Growth of singletons born after frozen embryo transfer until early adulthood: a Finnish register study

STUDY QUESTION

Are there growth differences between singleton children born after frozen embryo transfer (FET), fresh embryo transfer (ET), and natural conception (NC)?

SUMMARY ANSWER

Adolescent boys born after FET have a higher mean proportion and increased odds of overweight compared to those born after fresh ET.

WHAT IS KNOWN ALREADY

Children born after FET have higher mean birthweights and an increased risk of large-for-gestational-age compared to those born after fresh ET and even NC. This raises questions about possible growth differences later in childhood. Previous studies on child growth after FET report partly conflicting results and lack long-term data until adolescence.

STUDY DESIGN, SIZE, DURATION

This was a cohort study based on national population-based registers, the Finnish Medical Birth Register and the Register of Primary Health Care visits, including singletons born after FET (n = 1825), fresh ET (n = 2933), and NC (n = 31 136) in Finland between the years 1995 and 2006.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The proportions of overweight (i.e. age- and sex-adjusted ISO-BMI for children ≥ 25) were compared between the groups. Odds ratios (ORs) and adjusted odds ratios (aORs) of overweight were calculated. Adjustments were made for birth year, preterm birth, maternal age, parity, and socioeconomic status. Mean heights, weights, and BMIs were compared between the groups each year between the ages of 7 and 18.

MAIN RESULTS AND THE ROLE OF CHANCE

FET boys had a higher mean proportion of overweight (28%) compared to fresh ET (22%, P < 0.001) and NC (26%, P = 0.014) boys. For all ages combined, the aOR of overweight was increased (1.14, 95% CI 1.02-1.27) for FET boys compared to fresh ET boys. For girls, the mean proportions of overweight were 18%, 19%, and 22% for those born after FET, fresh ET, and NC, respectively (P = 0.169 for FET vs fresh ET, P < 0.001 for FET vs NC). For all ages combined, FET girls had a decreased aOR of overweight (0.89, 95% CI 0.80-0.99) compared to NC girls. Growth measurements were available for 6.9% to 30.6% of FET boys and for 4.7% to 29.4% of FET girls at different ages.

LIMITATIONS, REASONS FOR CAUTION

Unfortunately, we were not able to adjust for parental anthropometric characteristics. The growth data were not available for the whole cohort, and the proportion of children with available measurements was limited at the start and end of the follow-up. During the study period, mainly cleavage stage embryos were transferred, and slow freezing was used for ART.

WIDER IMPLICATIONS OF THE FINDINGS

The risk of overweight among FET boys warrants further research. Future studies should aim to investigate the mechanisms that explain this sex-specific finding and combine growth data with long-term health data to explore the possible risks of overweight and cardiometabolic disease in adulthood.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was obtained from the Päivikki and Sakari Sohlberg Foundation, the Alma and K.A. Snellman Foundation (personal grants to A.M.T.), and the Finnish Government Research Funding. The funding sources were not involved in the planning or execution of the study. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Serum erythropoietin level is increased during stimulation for IVF but not in OHSS

BACKGROUND

Erythropoietin (Epo) is a potent vascular growth factor that induces angiogenesis and antiapoptotic signalling. We investigated whether the development of numerous follicles and corpora lutea during in vitro fertilization (IVF) cycle affects circulating Epo levels and further, if Epo could be used as a novel marker for ovarian hyperstimulation syndrome (OHSS).

METHODS

24 women were included in the uncomplicated IVF group and 35 women in the OHSS group. Repeated blood samples from both groups were analysed for Epo, progesterone, blood haemoglobin, and creatinine. Follicular fluid from the IVF group was analysed for Epo and progesterone. Repeated measure analysis was performed for the variables and circulating Epo levels were compared between the IVF group and early OHSS. Furthermore, related growth factors, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1) were analysed from subgroup of women to test for correlation with Epo.

RESULTS

During IVF, circulating Epo increased from natural mid-luteal phase to stimulated mid-luteal phase (median 9.5; 95% CI 7.2-13.4 IU/L and 12.5; 10.3-13.4 IU/L; p = 0.003). In cycles resulting in pregnancy, Epo level decreased 14 days after oocyte pick-up (OPU) and remained low thereafter. In cycles not resulting in pregnancy, Epo level increased again 35 days after OPU. Follicle fluid Epo concentration was 1.5 times higher than the serum concentration (median 15.4; 95% CI 10.4-19.2 IU/L vs. 10.2; 8.8-12.7; p = 0.006). There was no difference in circulating Epo concentration between early OHSS and uncomplicated IVF. Circulating Epo did not correlate with VEGF or HIF-1.

CONCLUSIONS

Circulating Epo levels fluctuate during IVF cycle. We hypothesise this may suggest Epo's involvement in ovarian physiology and angiogenesis. However, Epo was not a clinical marker for OHSS.

Risk of congenital malformations in live-born singletons conceived after intracytoplasmic sperm injection: a Nordic study from the CoNARTaS group

OBJECTIVE

To investigate whether the risk of major congenital malformations is higher in live-born singletons conceived with intracytoplasmic sperm injection (ICSI) compared with in vitro fertilization (IVF)?

DESIGN

Nordic register-based cohort study.

SETTING

Cross-linked data from Medical Birth Registers and National ART and Patient Registers in Denmark, Norway and Sweden. Data were included from the year the first child conceived using ICSI was born: Sweden, 1992; Denmark, 1994; and Norway, 1996. Data were included until 2014 for Denmark and 2015 for Norway and Sweden.

PATIENT(S)

All live-born singletons conceived using fresh ICSI (n = 32,484); fresh IVF (n = 47,178); without medical assistance (n = 4,804,844); and cryo-ICSI (n = 7,200) during the study period.

INTERVENTION(S)

Different in vitro conception methods, and cryopreservation of embryos.

MAIN OUTCOME MEASURE(S)

Risk of major congenital malformations on the basis of International Classification of Diseases codes. The European Concerted Action on Congenital Anomalies and Twins was used to differentiate between major and minor malformations.

RESULT(S)

Among singletons conceived using fresh ICSI, 6.0% had a major malformation, compared with 5.3% of children conceived using fresh IVF; 4.2% of children conceived without medical assistance; and 4.9% of children conceived using cryo-ICSI; adjusted odds ratio (AOR) 1.07 (95% confidence interval [CI] 1.01-1.14) in ICSI vs. IVF; and AOR 1.28 (95% CI, 1.23-1.35) in ICSI vs. no medical assistance; and AOR 1.11 (95% CI, 0.99-1.26) in ICSI fresh vs. cryo-ICSI. When malformations were grouped by different organ systems, children conceived using ICSI had a higher risk of respiratory and chromosomal malformations compared with children conceived using IVF, but there were very few cases in each group. When categorizing children conceived using ICSI according to treatment indication (male factor infertility only vs. other indications), we found a higher risk of hypospadias when ICSI was performed because of male factor infertility only (AOR 1.85 [95% CI 1.03-332]). The indications for ICSI changed over time, as male factor infertility did not remain the primary indication for ICSI throughout the study period.

CONCLUSION(S)

In this large cohort study, we found the risk of major malformations in live-born singletons to be slightly higher after fresh ICSI compared with fresh IVF. These findings should be considered when choosing the assisted reproductive technology method for couples without male factor infertility.

Effects of letrozole on serum estradiol and estrone in postmenopausal breast cancer patients and tolerability of treatment: a prospective trial using a highly sensitive LC-MS/MS (liquid chromatography-tandem mass spectrometry) method for estrogen measurement

PURPOSE

To analyze serum estradiol (E2) and estrone (E1) during letrozole treatment and their association to Quality of Life (QoL) and side-effects.

METHODS

Postmenopausal breast cancer patients starting adjuvant letrozole were eligible. Serum samples were taken at baseline, three, and 12 months. E2 and FSH were measured with routine chemiluminescent immunoassays. E2 and E1 were analyzed after trial completion with a highly sensitive liquid chromatography-tandem mass spectrometry method (LC-MS/MS) with lower limits of quantification (LLOQ) of 5 pmol/L. QoL was measured at baseline and at 12 months with the EORTC QLQ-C30 and QLQ-BR23 and the Women's Health questionnaires, and menopause-related symptoms with the modified Kupperman Index.

RESULTS

Of 100 screened patients 90 completed the trial. Baseline mean LC-MS/MS E2 and E1 were 12 pmol/L (range < 5-57) and 66 pmol/L (< 5-226), respectively. E2 levels measured by immunoassay and LC-MS/MS showed no correlation. E2 and E1 were completely suppressed by letrozole except for one occasion (E1 11 pmol/L at 3 months). Pain, side effects of systemic therapy, vasomotor symptoms, joint and muscle aches, and vaginal dryness increased during letrozole treatment. A high baseline E2 was significantly associated with increased aching joints and muscles, but not with the other side effects.

CONCLUSIONS

Letrozole supresses E2 and E1 completely below the LLOQ of the LC-MS/MS in postmenopausal women. High pre-treatment E2 levels were associated with more joint and muscle pain during letrozole. Automated immunoassays are unsuitable for E2 monitoring during letrozole therapy due to poor sensitivity.

The challenges of selective fertility and carryover effects in within-sibship analyses: the effect of assisted reproductive technology on perinatal mortality as an example

BACKGROUND

Within-sibship analyses show lower perinatal mortality after assisted reproductive technology (ART) compared with natural conception (NC), a finding that appears biologically unlikely. We investigated whether this may be attributed to bias from selective fertility and carryover effects.

METHODS

Using data from national registries in Denmark (1994-2014), Finland (1990-2014) and Norway and Sweden (1988-2015), we studied 5 722 826 singleton pregnancies, including 119 900 ART-conceived and 37 590 exposure-discordant sibships. Perinatal mortality at the population level and within sibships was compared using multilevel logistic regression with random and fixed intercepts, respectively. We estimated selective fertility as the proportion of primiparous women with and without perinatal loss who had a second delivery, and carryover effects through bidirectional and crosswise associations.

RESULTS

Population analysis showed higher perinatal mortality among ART conception compared with NC (odds ratio 1.21, 95% CI 1.13 to 1.30), whereas within-sibship analysis showed the opposite (OR 0.36, 95% CI 0.31 to 0.43). Primiparous women with perinatal loss were more likely to give birth again (selective fertility) and to use ART in this subsequent pregnancy (carryover effects), resulting in strong selection of double-discordant sibships with death of the naturally conceived and survival of the ART-conceived sibling. After controlling for conception method and outcome in the first pregnancy, ART was not consistently associated with perinatal mortality in the second pregnancy.

CONCLUSIONS

Whereas population estimates may be biased by residual confounding, within-sibship estimates were biased by selective fertility and carryover effects. It remains unclear whether ART conception contributes to perinatal mortality.

Risk of ovarian cancer in women who give birth after assisted reproductive technology (ART)-a registry-based Nordic cohort study with follow-up from first pregnancy

BACKGROUND

There is concern that assisted reproductive technology (ART) may increase ovarian cancer risk, but previous studies are inconclusive. We compared ovarian cancer risk for women who gave birth after ART vs natural conception.

METHODS

Through linkage of nationwide registry data, we followed 3,303,880 initially nulliparous women in Denmark (1994-2014), Finland (1990-2014), Norway (1984-2015) and Sweden (1985-2015) from first pregnancy ≥22 weeks to ovarian cancer, emigration, death or end of follow-up (2014/2015). We estimated hazard ratios (HRs), adjusting for age, parity, maternal birth year and country, and for body mass index and smoking in subsamples.

RESULTS

Mean age at first birth was 27.7 years. During a mean follow-up of 14.4 person-years, 2683 participants (0.08%) developed ovarian cancer; 135 after ART and 2548 after natural conception only (incidence rates 11.6 and 5.5 per 100,000 person-years, respectively). The risk was higher for women who ever gave birth after ART (HR 1.70, 95% confidence interval 1.42-2.03) compared to natural conception. Associations were stronger for conventional in vitro fertilisation than for intracytoplasmic sperm injection.

CONCLUSIONS

Among parous women, ART-conception was associated with a higher risk of ovarian cancer than natural conception. Further studies should decipher whether this is causal or confounded by infertility or other factors.

Risk of stillbirth and neonatal death in singletons born after fresh and frozen embryo transfer: cohort study from the Committee of Nordic Assisted Reproduction Technology and Safety

OBJECTIVES

To investigate whether risks of stillbirth and neonatal death differ after fresh embryo transfers (fresh-ETs) and frozen embryo transfers (frozen-ETs) compared with singletons conceived without medical assistance.

DESIGN

A population-based cohort study.

SETTING

Not applicable.

PATIENT(S)

Data linkage between the nationwide Medical Birth Registries in Denmark (1994-2014), Norway and Sweden (1988-2015), and national quality registries and databases on assisted reproductive technology identified a total of 4,590,853 singletons, including 78,642 conceived by fresh-ET and 18,084 by frozen-ET.

INTERVENTION(S)

None MAIN OUTCOME MEASURE(S): Stillbirth (fetal death before and during delivery) and neonatal death (live born with death 0-27 days postpartum).

RESULT(S)

Overall, 17,123 (0.37%) singletons were stillborn and 7,685 (0.17%) died neonatally. Compared with singletons conceived without medical assistance, the odds of stillbirth were similar after fresh-ET and frozen-ET, whereas the odds of neonatal death were high after fresh-ET (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.46-1.95) and frozen-ET (OR, 1.51; 95% CI, 1.08-2.10). Preterm birth (<37 gestational weeks) was more common after fresh-ET (8.0%) and frozen-ET (6.6%) compared with singletons conceived without medical assistance (5.0%), and strongly associated with neonatal mortality across all conception methods. Within gestational age categories, risk of stillbirth and neonatal death was similar for all conception methods, except that singletons from fresh-ET had a higher risk of stillbirth during gestational week 22-27 (OR, 1.85; 95% CI, 1.51-2.26).

CONCLUSION(S)

Overall, the risk of stillbirth was similar after fresh-ET and frozen-ET compared with singletons conceived without medical assistance, whereas neonatal mortality was high, possibly mediated by the high risk of preterm birth when compared with singletons conceived without medical assistance. Our results gave no clear support for choosing one treatment over the other.

Risk of Hypertensive Disorders in Pregnancy After Fresh and Frozen Embryo Transfer in Assisted Reproduction: A Population-Based Cohort Study With Within-Sibship Analysis

BACKGROUND

Frozen embryo transfer (frozen-ET) is increasingly common because of improved cryopreservation methods and elective freezing of all embryos. Frozen-ET is associated with higher risk of hypertensive disorders in pregnancy than both natural conception and fresh embryo transfer (fresh-ET), but whether this is attributable to parental factors or treatment is unknown.

METHODS

Using the Medical Birth Registries of Denmark (1994-2014), Norway, and Sweden (1988-2015), linked to data from national quality registries and databases on assisted reproduction, we designed a population-based cohort study with within-sibship comparison. We included 4 426 691 naturally conceived, 78 300 fresh-ET, and 18 037 frozen-ET singleton pregnancies, of which 33 209 sibships were conceived using different conception methods. Adjusted odds ratios (aOR) of hypertensive disorders in pregnancy for fresh-ET and frozen-ET versus natural conception with 95% CI were estimated using multilevel logistic regression, where random effects provided conventional population-level estimates and fixed effects gave within-sibship estimates. Main models included adjustment for birth year, maternal age, parity, and country.

RESULTS

Risk of hypertensive disorders in pregnancy was higher after frozen-ET compared to natural conception, both at population-level (7.4% versus 4.3%, aOR, 1.74 [95% CI, 1.61-1.89]) and within sibships (aOR, 2.02 [95% CI, 1.72-2.39]). For fresh-ET, risk was similar to natural conception, both at population-level (aOR, 1.02 [95% CI, 0.98-1.07]) and within sibships (aOR, 0.99 [95% CI, 0.89-1.09]).

CONCLUSIONS

Frozen-ET was associated with substantially higher risk of hypertensive disorders in pregnancy, even after accounting for shared parental factors within sibships.

The effect of paternal and maternal factors on the prognosis of live birth in couples with recurrent pregnancy loss

INTRODUCTION

Currently, recurrent pregnancy loss (RPL) examinations focus on the woman, although paternal factors are also involved. Men in couples with RPL have higher sperm DNA fragmentation levels than fertile men, but the effect of sperm DNA damage on couple's later prognosis is unknown. Advanced maternal age and obesity are associated with RPL, but paternal lifestyle factors are less studied. Therefore, we aimed to study the associations of couples' lifestyle factors, causes of RPL, and sperm DNA fragmentation with their prognosis of future live birth.

MATERIAL AND METHODS

This descriptive cohort study comprised 506 couples investigated for RPL at Helsinki University Hospital, Finland, between 2007 and 2016, linked with national health and population registers. The primary outcome was couple's live birth after RPL investigations. Data on couple's background factors, including age, body mass index, smoking, and alcohol use, were collected from medical records. Sperm DNA fragmentation index was analyzed from 211 men using the sperm chromatin dispersion test. The associations between background factors, sperm DNA fragmentation, and cumulative probability of live birth over time were analyzed using cross-tabulations and age-adjusted Cox regression.

RESULTS

In all, 352 of 506 couples (69.6%) achieved live birth. Maternal age, unexplained RPL, prolonged pregnancy attempts before investigations, paternal obesity, and maternal smoking were associated with prognosis: unadjusted hazard ratio for couple's live birth for women aged 35-39 vs younger than 30 years was 0.63 (95% confidence interval [CI] 0.47-0.84), and for 40 years or older was 0.36 (95% CI 0.22-0.58). Age-adjusted hazard ratio for unexplained vs explained RPL was 1.39 (95% CI 1.12-1.72), for couple's pregnancy attempt at least 4 years vs less than 2 years was 0.50 (95% CI 0.33-0.76), for paternal body mass index at least 30 kg/m² vs less than 25 kg/m² was 0.67 (95% CI 0.46-0.98), and for maternal smoking was 0.71 (95% CI 0.51-0.99). Altogether, 96/135 (71.1%) couples with normal (<15%), 38/60 (63.3%) with intermediate (15-30%), and 11/16 (68.8%) with high sperm DNA fragmentation index achieved live birth (p = 0.56).

CONCLUSIONS

In couples with RPL, prolonged pregnancy attempts, a cause found in RPL examinations, lifestyle factors, and maternal age are negatively associated with their prognosis of future live birth. Sperm DNA fragmentation was not associated, but the number of men with damaged spermatozoa was small. We suggest that clinicians include women and men in RPL counseling because couple's joint lifestyle seems to determine their later prognosis.

Health of singletons born after frozen embryo transfer until early adulthood: a Finnish register study

STUDY QUESTION

Is the health of singletons born after frozen embryo transfer (FET) comparable to that of singletons born after fresh embryo transfer (ET) until early adulthood?

SUMMARY ANSWER

The health of singletons born after FET does not differ from that of singletons born after fresh ET.

WHAT IS KNOWN ALREADY

The differences in perinatal outcomes of children born after FET and fresh ET are well known. FET is associated with an increased risk of large-for-gestational-age but diminished risks of preterm birth (PTB), small-for-gestational-age and decreased perinatal mortality compared to fresh ET. However, knowledge on the long-term health after FET is scarce.

STUDY DESIGN, SIZE, DURATION

This retrospective register-based cohort study compares singletons born after FET (n = 1825) between the years 1995 and 2006 to those born after fresh ET (n = 2933) and natural conception (NC, n = 31 136) with a mean follow-up time of 18-20 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Singletons born after FET were compared to those born after fresh ET and NC regarding the frequencies of diagnoses in the main ICD-10 chapters (International Statistical Classification of Diseases and Related Health Problems, 10th revision), the number of outpatient visits and hospital admissions, and mortality. Adjustments were made for PTB, maternal age, parity, socioeconomic status based on mother's occupation and offspring sex. The study combines data from the Finnish Medical Birth Register, the Finnish Care Register for Health Care (CRHC) and the Cause-of-Death Register at Statistics Finland. The Student's T-test was used for continuous variables, and the Chi-square test was used for categorical variables. Cox regression was used to estimate crude and adjusted hazard ratios (HRs and aHRs, respectively). A general linear model was used to compare the means of outpatient visits, hospital admissions and lengths of hospital stays per person.

MAIN RESULTS AND THE ROLE OF CHANCE

No significant differences between the FET and fresh ET groups were found in the frequency of diagnoses in any of the ICD-10 chapters or in the parameters describing the need for hospital care. However, compared to the NC group, higher proportions in the FET group had outpatient visits in the hospital (93.5% vs 92.2%, aHR 1.23, 95% CI 1.17, 1.30) or hospital admissions (48% vs 46.5%, aHR 1.28, 95% CI 1.19, 1.37). Compared to the NC group, the FET group had elevated adjusted risks of diagnoses of infectious and parasitic diseases (aHR 1.24; 95% CI 1.11, 1.38), neoplasms (aHR 1.68; 95% CI 1.48, 1.91), diseases of the eye and adnexa, the ear or mastoid process (aHR 1.11; 95% CI 1.01, 1.21), the respiratory system (aHR 1.15; 95% CI 1.06, 1.23), the digestive system (aHR 1.17; 95% CI 1.05, 1.32), the skin or subcutaneous tissue (aHR 1.28; 95% CI 1.14, 1.43) and the genitourinary system (aHR 1.27; 95% CI 1.11, 1.45), as well as congenital malformations or chromosomal abnormalities (aHR 1.31; 95% CI 1.14, 1.50) and symptoms, signs or abnormal clinical or laboratory findings (aHR 1.25, 95% CI 1.16, 1.34).

LIMITATIONS, REASONS FOR CAUTION

Only hospital-based inpatient and outpatient care is covered by the CRHC register, excluding milder cases diagnosed elsewhere. We were not able to study the effect of ART treatments and subfertility separately in our setting. In addition, although our cohort is reasonably sized, even larger cohorts would be needed to reliably study rare outcomes, such as cancer.

WIDER IMPLICATIONS OF THE FINDINGS

For many ICD-10 chapters, we present the first published data on the long-term outcome of singletons born after FET. The results on FET versus fresh ET are reassuring, whereas the results on FET versus NC warrant further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

Finnish government research funding was obtained for this study. Funding was also obtained from the Finnish Medical Society Duodecim, the Päivikki and Sakari Sohlberg Foundation, Orion Research Foundation, Finnish Society of Obstetrics and Gynaecology (research grants to A.M.T.) and Finnish government research funding. The funding sources were not involved in the planning or execution of the study. The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Cancer in children born after frozen-thawed embryo transfer: A cohort study

BACKGROUND

The aim was to investigate whether children born after assisted reproduction technology (ART), particularly after frozen-thawed embryo transfer (FET), are at higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception.

METHODS AND FINDINGS

We performed a registry-based cohort study using data from the 4 Nordic countries: Denmark, Finland, Norway, and Sweden. The study included 7,944,248 children, out of whom 171,774 children were born after use of ART (2.2%) and 7,772,474 children were born after spontaneous conception, representing all children born between the years 1994 to 2014 in Denmark, 1990 to 2014 in Finland, 1984 to 2015 in Norway, and 1985 to 2015 in Sweden. Rates for any cancer and specific cancer groups in children born after each conception method were determined by cross-linking national ART registry data with national cancer and health data registries and population registries. We used Cox proportional hazards models to estimate the risk of any cancer, with age as the time scale. After a mean follow-up of 9.9 and 12.5 years, the incidence rate (IR) of cancer before age 18 years was 19.3/100,000 person-years for children born after ART (329 cases) and 16.7/100,000 person-years for children born after spontaneous conception (16,184 cases). Adjusted hazard ratio (aHR) was 1.08, 95% confidence interval (CI) 0.96 to 1.21, p = 0.18. Adjustment was performed for sex, plurality, year of birth, country of birth, maternal age at birth, and parity. Children born after FET had a higher risk of cancer (48 cases; IR 30.1/100,000 person-years) compared to both fresh embryo transfer (IR 18.8/100,000 person-years), aHR 1.59, 95% CI 1.15 to 2.20, p = 0.005, and spontaneous conception, aHR 1.65, 95% CI 1.24 to 2.19, p = 0.001. Adjustment either for macrosomia, birth weight, or major birth defects attenuated the association marginally. Higher risks of epithelial tumors and melanoma after any assisted reproductive method and of leukemia after FET were observed. The main limitation of this study is the small number of children with cancer in the FET group.

CONCLUSIONS

Children born after FET had a higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception. The results should be interpreted cautiously based on the small number of children with cancer, but the findings raise concerns considering the increasing use of FET, in particular freeze-all strategies without clear medical indications.

TRIAL REGISTRATION

Trial registration number: ISRCTN 11780826.

Puberty disorders among ART-conceived singletons: a Nordic register study from the CoNARTaS group

STUDY QUESTION

Do ART-conceived children have an increased risk for puberty disorders?

SUMMARY ANSWER

Both ART-conceived boys and girls had a higher risk of puberty disorders; early puberty was more common among girls and late puberty among boys.

WHAT IS KNOWN ALREADY

Some physiological differences in growth and metabolism have been reported for ART-conceived children compared to non-ART-conceived children. Knowledge on pubertal development and disorders in ART-conceived children is limited.

STUDY DESIGN, SIZE, DURATION

A register-based cohort study was carried out including data from 1985 to 2015. The Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS) study population consists of all live and stillborn children, as well as their mothers, registered in the Medical Birth Registers during the study period in Denmark, Sweden, Finland and Norway.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 122 321 ART-conceived singletons and 6 576 410 non-ART singletons born in Denmark (1994–2014), Finland (1990–2014), Norway (2002–2015) and Sweden (1985–2015) were included. Puberty disorders were defined using International Classification of Diseases and Related Health Problems (ICD)-9/ICD-10 codes and classified in the following groups: late puberty (6268/E30.0), early puberty (2591 and 2958/E30.1 and E30.8) and unspecified disorders (V212 and V579/E30.9 and Z00.3 as well as Z51.80 for Finland). The results in Cox regression were adjusted for maternal age, parity, smoking, gestational diabetes, chronic hypertension, hypertensive disorders during pregnancy and country, and further for either gestational age, birthweight, small for gestational age or large for gestational age.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 37 869 children with diagnoses related to puberty disorders, and 603 of them were born after ART. ART-conceived children had higher risks for early (adjusted hazard ratio (aHR) 1.45, 95% CI: 1.29–1.64) and late puberty (aHR 1.47, 95% CI: 1.21–1.77). Girls had more diagnoses related to early puberty (aHR 1.46, 95% CI: 1.29–1.66) and boys with late puberty (aHR 1.55, 95% CI: 1.24–1.95).

LIMITATIONS, REASONS FOR CAUTION

Using reported puberty disorders with ICD codes in health care registers might vary, which may affect the numbers of cases found in the registers. Register data may give an underestimation both among ART and non-ART-conceived children, especially among non-ART children, who may not be as carefully followed as ART-conceived children. Adjustment for causes and duration of infertility, mothers’ own puberty characteristics and BMI, as well as children’s BMI, was not possible because data were not available or data were missing for the early years. It was also not possible to compare ART to non-ART siblings or to study the pubertal disorders by cause of subfertility owing to a small number of discordant sibling pairs and a large proportion of missing data on cause of subfertility.

WIDER IMPLICATIONS OF THE FINDINGS

This large, register-based study suggests that ART-conceived children have a higher risk for puberty disorders. However, the mechanisms of infertility and pubertal onset are complex, and ART is a rapidly advancing field with various treatment options. Studying the pubertal disorders of ART-conceived offspring is a continuing challenge.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (71450), the Central Norway Regional Health Authorities (46045000), the Nordic Federation of Obstetrics and Gynaecology (NF13041, NF15058, NF16026 and NF17043), the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project), the Research Council of Norway’s Centre of Excellence funding scheme (262700), the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-70940) and FLUX Consortium ‘Family Formation in Flux—Causes, Consequences and Possible Futures’, funded by the Strategic Research Council, Academy of Finland (DEMOGRAPHY 345130). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Top-quality embryo transfer is associated with lower odds of ectopic pregnancy

INTRODUCTION

The incidence of ectopic pregnancy is up to four times higher after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) than in spontaneous pregnancies, and the risk of ectopic pregnancy is increased by tubal factor infertility and the transfer of multiple embryos. However, the effect of embryo quality on the probability of ectopic pregnancy has not been investigated until now and it is not clear whether ovarian stimulation parameters affect the incidence of ectopic pregnancy.

MATERIAL AND METHODS

An historical cohort study of 15 006 clinical pregnancies (diagnosed by ultrasound at 6-8 gestational weeks) after non-donor IVF/ICSI with fresh embryo transfer (n = 8952) or frozen-thawed embryo transfer (n = 6054). Treatments were performed during 2000-2017 in Finland. A total of 9207 (61.4%) single and 5799 (38.6%) double embryo transfers of no more than one top-quality embryo were evaluated. We analyzed the effects of multiple factors on ectopic pregnancy by logistic regression, including type of cycle (fresh vs frozen embryo transfer), female age, number and quality of embryos transferred, tubal factor infertility and factors of ovarian response to gonadotropin stimulation.

RESULTS

Ectopic pregnancy was observed in 2.3% of cycles. There was no significant difference in ectopic pregnancy rate after fresh embryo transfer and frozen embryo transfer (2.2% vs 2.4%, p = 0.3). The ectopic pregnancy rate was lower in cycles with top-quality embryo transfer (1.9%) than of those where only non-top quality embryos were transferred (2.7%, p < 0.0001). Tubal factor infertility was diagnosed more often in ectopic pregnancy than in intrauterine pregnancies (21.2% vs 11.0%, p < 0.0001). Logistic regression revealed lower odds for ectopic pregnancy after a top-quality embryo transfer than after transfer of a non-top quality embryo (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.56-0.92, p = 0.007). Transfer of two vs one embryo (OR 1.35, 95% CI 1.05-1.70, p = 0.02) and tubal factor infertility (OR 2.21, 95% CI 1.68-2.91, p < 0.0001) significantly increased the risk of ectopic pregnancy.

CONCLUSIONS

Transfer of non-top quality embryos is associated with a higher rate of ectopic pregnancy. This is particularly important to keep in mind in treatments with only non-top embryos available even in the absence of tubal factor infertility. To minimize the risk of ectopic pregnancy, the number of embryos transferred should be as low as possible.

O-274 Cancer in Children Born after Frozen-Thawed Embryo Transfer: A Cohort Study

Study question

Do children conceived after assisted reproductive technology (ART), particularly after frozen/thawed embryo transfer (FET), have a higher risk of cancer?

Summary answer

Children born after FET have a higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception.

What is known already

Previous studies on the association of ART conception and risk of childhood cancer show conflicting results. Worldwide, the number of children born after FET increases and in many countries the number of children born after FET now exceeds the number of children born after fresh embryo transfer. Children born after FET are at increased risk of macrosomia which has been associated with a higher risk of childhood cancer.

Study design, size, duration

This large Nordic registry-based cohort study included 171 774 children born after use of ART and 7 772 474 children born after spontaneous conception during a study period of up to three decades (Denmark 1994-2014, Finland 1990-2014, Norway 1984-2015 and Sweden 1985-2015).

Participants/materials, setting, methods

Cancer rates in children born after each conception method were determined by cross-linking data from national ART and birth registries, national cancer and population registries. The primary outcome was any cancer, and secondary outcomes were 12 cancer subgroups according to the International Classification of Childhood Cancer (ICCC-3). Children were followed from birth to cancer diagnosis, death, emigration, age 18 years or the end of the study period, whichever came first.

Main results and the role of chance

Mean follow up was 9.9 years for children born after ART and 12.5 years for children born after spontaneous conception. Incidence rate (IR) of any cancer before 18 years of age was 19.3/100 000 person-years for children born after ART (329 cases) and 16.7/100 000 person-years for children born after spontaneous conception. Adjusted hazard ratio (aHR) was 1.08, 95% confidence interval (CI) 0.96-1.21. Adjustment was performed for sex, plurality, country of birth, year of birth, maternal age at birth, and parity. Children born after FET had a higher risk of any cancer (48 cases, IR 30.1/100 000 person-years), compared to both children born after fresh embryo transfer (227 cases, IR 18.8/100 000 person-years) (aHR 1.59, 95% CI, 1.15 to 2.20) and children born after spontaneous conception (aHR 1.64, 95% CI, 1.24 to 2.19). Adjustment for macrosomia (birthweight &lt;/≥4000 g), birthweight (continuous variable) or major birth defects only slightly attenuated the association. For cancer subgroups, higher risks of epithelial tumours and melanoma after any ART and of leukaemia after FET were observed.

Limitations, reasons for caution

The main limitation is the number of children with cancer in the FET group. Although including a large cohort, the number of children with cancer is of moderate size. Furthermore, all data are observational, and residual confounding by factors as genetics, parental preconception health and lifestyle cannot be excluded.

Wider implications of the findings

While risk of any cancer was not higher in children born after any ART, we found that children born after FET had a higher risk of cancer than children born after fresh transfer and spontaneously conceived children. These findings are important considering the increasing use of the freeze-all strategy.

Trial registration number

ISRCTN11789826

O-084 Risk of breast cancer for women who give birth after conception by assisted reproductive technology versus natural conception - a Nordic cohort study

Study question

Are women who give birth after assisted reproductive technology (ART) at higher risk of breast cancer than women who give birth after natural conception?

Summary answer

Risk of breast cancer was similar or lower for women who gave birth after ART-conception compared to women who gave birth after natural conception.

What is known already

Most studies indicate no increase in breast cancer risk after use of ART, but results have been conflicting and with limited confounder control. Interpretation of existing knowledge is further complicated by the well-established dual effect of pregnancy on breast cancer risk, with short-term increase in risk and long-term protection. The population of ART-treated women is still relatively young and further studies are needed to understand how fertility treatment, pregnancy and causes of infertility collectively influence breast cancer risk in women treated with ART.

Study design, size, duration

Cohort study based on data linkage between the Medical Birth Registries, ART Registries, Population and Cause of Death Registries in Denmark (1994-2014), Finland (1990-2014), Norway (1984-2015) and Sweden (1985-2015) and the Cancer Registries in each country (1958-2014, 1954-2014, 1953-2015, 1958-2015, respectively). We included 2,283,592 women who gave their first birth during the study period, at age ≥25 years. Among these, 111,781 women had at least one birth after ART conception.

Participants/materials, setting, methods

Women without prior cancer were followed from first birth to date of first cancer, death, emigration, or end of follow-up. We compared risk of breast cancer in Cox regression for women who ever gave birth after ART (time-dependent) vs women with birth(s) after natural conception only, using age as the time scale. We included age at first birth, parity (time-dependent), country and year of delivery as covariates. Sub-analyses included height, body mass index and smoking.

Main results and the role of chance

Women who gave birth after ART were on average 3 years older than women who gave birth after natural conception. Among women who gave birth after ART, 1,101 were diagnosed with breast cancer during a median follow-up of 8.8 years (incidence rate 101/100,000 person-years), compared to 26,984 cases during a median follow-up of 12.7 years (incidence rate 91/100,000 person-years) among women with naturally conceived pregnancies. Age-specific rates were similar. After covariate adjustment, risk was slightly lower for women with ART vs natural conception (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.87 - 0.99). Further adjustment for height, body mass index and smoking gave similar results. Age at first birth was not clearly associated with breast cancer risk for women with either conception method. Women with ART-conception in their first two pregnancies had lower risk (HR 0.83, 95% CI 0.70 - 0.98), whereas no clear differences were found for women with both conception methods, compared to women with two naturally conceived pregnancies. Associations according to ART indication (male, ovarian, other female and unexplained infertility) were consistent with the main findings, as were results for treatment type (IVF, ICSI, fresh and frozen transfer, and single or double embryo transfer).

Limitations, reasons for caution

We had no data on unsuccessful ART treatments, number or type of stimulation cycles. Because only women who gave birth were included, and because a large proportion of ART-treated women had unknown cause of infertility, we cannot exclude residual confounding from causes or severity of infertility.

Wider implications of the findings

Women with successful ART treatment had similar or slightly lower risk of breast cancer compared to women who gave birth after natural conception. Although this study could not completely rule out adverse effects of ART on breast cancer risk, we found no evidence to support strong adverse effects.

Trial registration number

Not applicable

O-273 Risk of hypertensive disorders in pregnancy after fresh and frozen embryo transfer in assisted reproduction: A population-based cohort study with within sibship analysis

Study question

Is the risk of hypertensive disorders in pregnancy (HDP) increased following assisted reproductive technology (ART) with fresh or frozen cycles compared to conception without ART?

Summary answer

Pregnancies after frozen embryo transfer (FET) had a substantially higher risk of HDP, also after accounting for constant parental factors in within sibship comparisons.

What is known already

FET in assisted reproductive technology (ART) is increasingly common because of improved cryopreservation methods, blastocyst culture, and freeze-all practice. Conventional observational studies have raised concerns about treatment safety due to higher risk of HDP after FET compared to both non-ART and fresh embryo transfer (fresh-ET). Whether this is attributable to parental factors or treatment is unknown. Within sibship comparisons can provide unique insight by controlling for confounding from unmeasured, constant parental factors, like genetics, preconception lifestyle and health, as well as socioeconomic status.

Study design, size, duration

Population-based cohort study with within sibship comparison using health registry data from three Nordic countries. In total, 4,523,028 singleton pregnancies resulting in delivery between 1988 and 2015 were included, of which 78,300 were after fresh-ET, and 18,037 were after FET. We identified 33,209 sibships that were conceived using two or three different conception methods (fresh-ET, FET, and non-ART).

Participants/materials, setting, methods

Data were collected from several national health registries in Denmark, Norway, and Sweden, including ART, medical birth, and patient registries, and linked using the residents’ unique identification numbers. Adjusted odds ratios (aOR) of HDP with 95% confidence intervals (CI) were estimated using multilevel logistic regression, where random effects provided conventional population estimates, and fixed effects gave within sibship estimates. Main models included adjustment for maternal age, parity, birth year and country.

Main results and the role of chance

Risk of HDP was higher after FET compared to non-ART conception, both at the population level (7.4% vs 4.3%, aOR 1.74, 95% CI 1.61 to 1.89) and within sibships (aOR 2.02, 95% CI 1.72 to 2.39). For fresh-ET, the risk was similar to non-ART, both at the population level (5.9% vs 4.3%, aOR 1.02, 95% CI 0.98 to 1.07) and within sibships (aOR 0.99, 95% CI 0.89 to 1.09). Sensitivity analyses with adjustment for body mass index (BMI) and smoking, restriction to full siblings (same mother and father) and siblings born within a three-year interval, were all consistent with our main findings. Furthermore, the results were not driven by order of conception method or other ART procedures (intracytoplasmic sperm injection, culture duration or number of embryos transferred).

Limitations, reasons for caution

Despite the extra control for shared confounders provided by the within sibship analyses, we cannot exclude residual confounding from non-shared confounders, such as smoking and BMI, where confounder control was limited by a large proportion of missingness, and causes of infertility, which were largely unknown.

Wider implications of the findings

Our findings are important for the ongoing discussion about the freeze-all policy, and further investigation of which treatment factors might be involved is warranted.

Trial registration number

Not applicable

O-303 Recurrent pregnancy loss is associated with unfavorable composition of endometrial and vaginal microbiota

Study question

Does endometrial or vaginal microbiota composition associate with recurrent pregnancy loss (RPL)?

Summary answer

Reduced relative abundance of Lactobacillus crispatus in endometrium and increased relative abundance of Gardnerella vaginalis in endometrium and vagina were associated with RPL.

What is known already

Dysbiotic vaginal microbiota associates with sporadic miscarriage and the depletion of lactobacilli in the endometrium has been associated with poor IVF outcomes, but their association with RPL has not been studied.

Study design, size, duration

A nested case-control study of 47 women investigated for RPL and 39 healthy control women without a history of pregnancy loss were recruited between March 2018 and December 2020 at a university hospital. Endometrial biopsies and vaginal samples were collected from the women 6-8 days after positive ovulation test result.

Participants/materials, setting, methods

The endometrial and vaginal microbiota compositions, analysed using 16S rRNA gene amplicon sequencing, were compared between RPL women and controls, and between individual vaginal and endometrial samples. The mycobiota composition was analysed using internal transcribed spacer 1 amplicon sequencing for a descriptive summary. The models were adjusted for BMI, age, and parity. False discovery rate -corrected P-values (q-values) were used to define nominal statistical significance at q&lt; 0.05.

Main results and the role of chance

Lactobacillus crispatus was less abundant in the RPL women’s endometrial samples compared to controls (mean relative abundance 17.2% vs. 45.6%, q= 0.04). Gardnerella vaginalis was more abundant in RPL women than in controls in both endometrial (12.4% vs. 5.8%, q&lt; 0.001) and vaginal samples (8.7% vs. 5.7%, q&lt; 0.01). The individual vaginal and endometrial microbial compositions correlated strongly (R = 0.85, P&lt; 0.001). Fungi, mostly Candida albicans, were detected in 22% of the endometrial and 36% of the vaginal samples.

Limitations, reasons for caution

Limitations include the transcervical sampling technique with a potential risk of cervicovaginal contamination of endometrial samples, the loss of a proportion of the samples from statistical analyses due to their low read count, and the presentation of the 16S rRNA sequencing results in relative rather than absolute abundances

Wider implications of the findings

Our findings suggest that an unfavorable endometrial microbiota may be a novel risk factor for RPL. Further studies should elucidate the mechanisms, how microbiota may predispose to RPL, possibilities to modify microbiota by treatments, and the effects of such treatments on the success of future pregnancies in couples having RPL.

Trial registration number

not applicable

Adolescent attachment to parents and peers in singletons and twins born with assisted and natural conception

STUDY QUESTION

Does adolescent attachment to parents and peers differ between singletons and twins born with ART or natural conception (NC)?

SUMMARY ANSWER

Adolescent attachment anxiety with the father was higher among NC singletons than among ART and NC twins, whereas attachment avoidance with the father was higher in ART singletons than in NC singletons and NC twins. No differences were found in attachment to the mother, best friend or romantic partner.

WHAT IS KNOWN ALREADY

Most studies have not found differences between ART and NC singletons in parent–adolescent relationships, but twin relationships may be more at risk. No previous study has examined all four groups in the same study, or specifically looked at attachment relationships.

STUDY DESIGN, SIZE, DURATION

This was an 18-year, prospective and controlled longitudinal study with families of 496 ART singletons, 101 ART twin pairs, 476 NC singletons and 22 NC twin pairs. Families were recruited during the second trimester of pregnancy; the ART group was recruited from five infertility clinics in Finland and the control group was recruited from a hospital outpatient clinic during a routine visit.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Mothers and fathers gave background information for this study during pregnancy, and during the child’s first year and early school age (7–8 years). For the ART group, infertility characteristics and prenatal medical information was also obtained from the patient registry of the infertility clinics. Children (originally 50% girls) filled in electronic questionnaires related to their attachment to mother, father, best friend and romantic partner (Experiences in Close Relationships—Relationship Structures) at 17–19 years of age.

MAIN RESULTS AND THE ROLE OF CHANCE

Adolescent attachment anxiety to father was higher in NC singletons than in ART twins, P = 0.004 and marginally higher than in NC twins, P = 0.06. Adolescent attachment avoidance to father was higher in ART singletons than in NC singletons, P = 0.006 and marginally higher than in NC twins, P = 0.055.

LIMITATIONS, REASONS FOR CAUTION

The sample size was small especially in the NC twin group and there was drop-out over the 18-year time period, especially among boys and families with lower parental education level. The study only included native Finnish-speaking families. The results could differ in a more diverse population. ART singletons were younger and had fewer siblings than ART twins and NC children, and ART and NC twins had more newborn health risks than ART and NC singletons.

WIDER IMPLICATIONS OF THE FINDINGS

The study adds to a growing body of evidence that neither ART treatments nor being a twin places mother–child relationships or peer relationships at long-term risk. However, in our study, which was the first to examine both ART and twinhood simultaneously, we found that there may be more problems in father–adolescent relationships, but only in ART singletons and only related to attachment avoidance. Our findings suggest that men, as well as women, should receive enough support in pre- and peri-natal health care during and after infertility treatments.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Academy of Finland (grant number 2501308988), the Juho Vainio Foundation and the Finnish Cultural Foundation. The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

The neurodevelopmental morbidity of children born after assisted reproductive technology: a Nordic register study from the Committee of Nordic Assisted Reproductive Technology and Safety group

OBJECTIVE

To assess the risk of neurodevelopmental disorders in singletons born after the use of assisted reproductive technology (ART) compared with singletons born without the use of ART.

DESIGN

Nordic register-based study.

SETTING

Cross-linked data from Medical Birth Registers and National ART and Patient Registers; liveborn singletons in 1995-2014 in Denmark and Finland, 2005-2015 in Norway, and 1995-2015 in Sweden with follow-up to 2014 (Denmark and Finland) or 2015 (Norway and Sweden).

PATIENTS

A total of 5,076,444 singletons: 116,909 (2.3%) born with and 4,959,535 (97.7%) born without the use of ART (non-ART).

INTERVENTIONS

In vitro fertilization, intracytoplasmic sperm injection, and fresh and frozen embryo transfer.

MAIN OUTCOME MEASURES

The primary outcomes (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, codes) were learning and motor functioning disorders (F80-F83), autism spectrum disorder (F84), attention-deficit/hyperactivity disorder and conduct disorders (F90-F92), and tic disorders (F95). Crude hazard ratios (HRs) and adjusted hazard ratios (aHRs) with 95% confidence intervals were calculated.

RESULTS

Singletons in the ART cohort had a higher adjusted risk of learning and motor functioning disorders (HR, 1.01 [0.96-1.07]; aHR, 1.17 [1.11-1.24]) and a tendency toward a higher risk of autism spectrum disorder (HR, 1.12 [1.04-1.21]; aHR, 1.07 [0.98-1.16]) and attention-deficit/hyperactivity disorder and conduct disorders (HR, 0.82 [0.77-0.86]; aHR, 1.17 [0.99-1.12]) but not of tic disorders (HR, 1.21 [1.06-1.38]; aHR, 1.17 [0.96-1.27]). No differences in risk were found between children born after in vitro fertilization and intracytoplasmic sperm injection or after fresh and frozen embryo transfer.

CONCLUSIONS

Our findings of only small differences in neurodevelopment between ART and non-ART singletons are reassuring and in line with previous studies.

Adolescent Attachment Profiles Are Associated With Mental Health and Risk-Taking Behavior

This person-oriented study aimed to identify adolescents' hierarchical attachment profiles with parents and peers, and to analyze associations between the profiles and adolescent psychosocial adjustment. Participants were 449 Finnish 17-19-year-olds reporting their attachments to mother, father, best friend, and romantic partner and details on mental health (internalizing symptoms, inattention/hyperactivity, and anger control problems) and risk-taking behavior (substance use and sexual risk-taking). Attachment was measured with Experiences in Close Relationships - Relationship Structures (ECR-RS); internalizing, inattention/hyperactivity, and anger control problems with Self-Report of Personality - Adolescent (SRP-A) of the Behavior Assessment System for Children, third edition (BASC-3); substance use with the Consumption scale of the Alcohol Use Disorders Identification Test (AUDIT-C) and items from the Finnish School Health Promotion Study; and sexual risk-taking behavior with the Cognitive Appraisal of Risky Events (CARE). Latent profile analysis identified five attachment profiles: "All secure" (39%), "All insecure" (11%), "Parents insecure - Peers secure" (21%), "Parents secure - Friend insecure" (10%), and "Parents secure - Partner insecure" (19%). "All insecure" adolescents showed the highest and "All secure" adolescents the lowest levels of mental health problems and substance use. Further, parental attachment security seemed to specifically prevent substance use and anger control problems, while peer attachment security prevented internalizing problems. Our findings help both understand the organization of attachment hierarchies in adolescence and refine the role of specific attachment relationships in psychosocial adjustment, which can be important for clinical interventions in adolescence.

Endocrine Disorders and Genital Infections Impair Gynecological Health in APECED (APS-1)

Objective

In autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) defects in the autoimmune regulator gene lead to impaired immunotolerance. We explored the effects of immunodeficiency and endocrinopathies on gynecologic health in patients with APECED.

Design

Cross-sectional cohort study combined with longitudinal follow-up data.

Methods

We carried out a gynecologic evaluation, pelvic ultrasound, and laboratory and microbiologic assessment in 19 women with APECED. Retrospective data were collected from previous study visits and hospital records.

Results

The study subjects' median age was 42.6 years (range, 16.7-65.5). Sixteen patients (84%) had premature ovarian insufficiency, diagnosed at the median age of 16.5 years; 75% of them used currently either combined contraception or hormonal replacement therapy. In 76% of women, the morphology and size of the uterus were determined normal for age, menopausal status, and current hormonal therapy. Fifteen patients (79%) had primary adrenal insufficiency; three of them used dehydroepiandrosterone substitution. All androgen concentrations were under the detection limit in 11 patients (58%). Genital infections were detected in nine patients (47%); most of them were asymptomatic. Gynecologic C. albicans infection was detected in four patients (21%); one of the strains was resistant to azoles. Five patients (26%) had human papillomavirus infection, three of which were high-risk subtypes. Cervical cell atypia was detected in one patient. No correlation between genital infections and anti-cytokine autoantibodies was found.

Conclusions

Ovarian and adrenal insufficiencies manifested with very low androgen levels in over half of the patients. Asymptomatic genital infections, but not cervical cell atypia, were common in female patients with APECED.

Childhood growth of term singletons born after frozen compared with fresh embryo transfer

RESEARCH QUESTION

Is the growth of term singletons born after frozen embryo transfer (FET) comparable to those born after fresh embryo transfer and natural conception up to 5 years of age?

DESIGN

Observational cohort study in an academic medical centre and municipal child health clinics with repeated measurements carried out by medical professionals. Term singletons born after FET (n = 110) and fresh embryo transfer (n = 181) and their matched natural conception controls (n = 543) born in Oulu, Northern Finland, were included. Mean weights, lengths, heights and head circumferences at the ages of 4, 8 and 18 months and 3 and 5 years were compared. At 3 and 5 years, body mass indices were compared.

RESULTS

Childhood growth did not differ between term singletons born after FET, fresh embryo transfer and natural conception, correcting for exact age at measurement and adjusting for maternal body mass index and paternal height.

CONCLUSIONS

Similar growth between children born after FET, fresh embryo transfer and natural conception offers reassurance of the safety and feasibility of the steadily increasing use of embryo cryopreservation in assisted reproduction.

Probability of live birth after IVF/ICSI treatments in female early onset cancer survivors: a Finnish population-based registry study

STUDY QUESTION

Does the probability of a live birth after fresh IVF/ICSI cycles with autologous oocytes differ in early onset female cancer survivors compared to their siblings?

SUMMARY ANSWER

The probability of a live birth was similar in female cancer survivors and siblings after four fresh IVF/ICSI cycles.

WHAT IS KNOWN ALREADY

Fertility preservation strategies are rapidly being developed to help female cancer patients who wish to have children later. However, there are only a few studies available on fertility treatments and following live births in female cancer survivors before fertility preservation strategies became available. In one of them, the probability of a live birth was reduced after assisted reproductive technology with autologous oocytes in cancer survivors compared to siblings.

STUDY DESIGN, SIZE, DURATION

In this retrospective, register-based study, data from Finnish registers on cancer, birth and prescribed medications were merged to identify 8944 female cancer survivors (diagnosed with cancer between 1953 and 2012 at the age of 0-40 years) and 9848 female siblings of survivors eligible for IVF/ICSI treatments between January 1993 and December 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Fresh IVF/ICSI cycles and following live birth rates (LBRs) within 22-48 weeks in cancer survivors and siblings at the age of 20-41 years were identified. A binomial regression model with log-link function was used to calculate risk ratio (RR) for live births after fresh IVF/ICSI cycles in survivors compared to siblings, adjusting for attained age and calendar time. A Poisson regression model was used to estimate incidence rate ratios (IRRs) for an IVF/ICSI treatment, as well as overall live births, including both pregnancies after fertility treatments and spontaneous pregnancies, in survivors compared to siblings.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed an overall decreased LBR, irrespective of IVF/ICSI treatments, in cancer survivors compared to siblings (IRR 0.68, 95% CI 0.64-0.71). All in all, 179 (2.0%) survivors and 230 (2.3%) siblings were prescribed fertility drugs for IVF/ICSI treatments (IRR 0.72, 95% CI 0.62-0.84). For the first fresh IVF/ICSI cycle, the LBR was 17.2% among survivors and 15.7% among siblings (RR 1.13, 95% CI 0.72-1.87). The mean LBR after four fresh IVF/ICSI cycles was not statistically different in survivors compared to siblings.

LIMITATIONS, REASONS FOR CAUTION

In this study, only IVF/ICSI treatments with autologous oocytes were included. The probability of a live birth after a frozen embryo transfer or oocyte donation could not be evaluated in this study. Information on miscarriages, extrauterine pregnancies or termination of pregnancies was not available.

WIDER IMPLICATIONS OF THE FINDINGS

For those early onset cancer survivors, who received IVF/ICSI treatments, the probability of live birth was not different from siblings who received IVF/ICSI treatments. However, an overall decreased LBR, irrespective of IVF/ICSI treatments, was observed in cancer survivors compared to siblings, indicating that cancer survivors receiving IVF/ICSI treatments in our study consisted of a selected group with at least a moderate ovarian reserve.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by a grant from the Cancer Foundation (Finland) (grant number 130079) and by a grant from LähiTapiola. The authors have no potential conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Cardiovascular disease, obesity, and type 2 diabetes in children born after assisted reproductive technology: A population-based cohort study

BACKGROUND

Some earlier studies have found indications of significant changes in cardiometabolic risk factors in children born after assisted reproductive technology (ART). Most of these studies are based on small cohorts with high risk of selection bias. In this study, we compared the risk of cardiovascular disease, obesity, and type 2 diabetes between singleton children born after ART and singleton children born after spontaneous conception (SC).

METHODS AND FINDINGS

This was a large population-based cohort study of individuals born in Norway, Sweden, Finland, and Denmark between 1984 and 2015. Data were obtained from national ART and medical birth registers and cross-linked with data from national patient registers and other population-based registers in the respective countries. In total, 122,429 children born after ART and 7,574,685 children born after SC were included. Mean (SD) maternal age was 33.9 (4.3) years for ART and 29.7 (5.2) for SC, 67.7% versus 41.8% were primiparous, and 45.2% versus 32.1% had more than 12 years of education. Preterm birth (<37 weeks 0 days) occurred in 7.9% of children born after ART and 4.8% in children born after SC, and 5.7% versus 3.3% had a low birth weight (<2,500 g). Mean (SD) follow-up time was 8.6 (6.2) years for children born after ART and 14.0 (8.6) years for children born after SC. In total, 135 (0.11%), 645 (0.65%), and 18 (0.01%) children born after ART were diagnosed with cardiovascular disease (ischemic heart disease, cardiomyopathy, heart failure, or cerebrovascular disease), obesity or type 2 diabetes, respectively. The corresponding values were 10,702 (0.14%), 30,308 (0.74%), and 2,919 (0.04%) for children born after SC. In the unadjusted analysis, children born after ART had a significantly higher risk of any cardiovascular disease (hazard ratio [HR] 1.24; 95% CI 1.04-1.48; p = 0.02), obesity (HR 1.13; 95% CI 1.05-1.23; p = 0.002), and type 2 diabetes (HR 1.71; 95% CI 1.08-2.73; p = 0.02). After adjustment, there was no significant difference between children born after ART and children born after SC for any cardiovascular disease (adjusted HR [aHR]1.02; 95% CI 0.86-1.22; p = 0.80) or type 2 diabetes (aHR 1.31; 95% CI 0.82-2.09; p = 0.25). For any cardiovascular disease, the 95% CI was reasonably narrow, excluding effects of a substantial magnitude, while the 95% CI for type 2 diabetes was wide, not excluding clinically meaningful effects. For obesity, there was a small but significant increased risk among children born after ART (aHR 1.14; 95% CI 1.06-1.23; p = 0.001). Important limitations of the study were the relatively short follow-up time, the limited number of events for some outcomes, and that the outcome obesity is often not considered as a disease and therefore not caught by registers, likely leading to an underestimation of obesity in both children born after ART and children born after SC.

CONCLUSIONS

In this study, we observed no difference in the risk of cardiovascular disease or type 2 diabetes between children born after ART and children born after SC. For obesity, there was a small but significant increased risk for children born after ART.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

Cerebral palsy in ART children has declined substantially over time: a Nordic study from the CoNARTaS group

STUDY QUESTION

Are the decreasing multiple birth rates after ART associated with a simultaneous drop in the incidence of cerebral palsy (CP) in ART children over time?

SUMMARY ANSWER

The relative odds of CP in ART children have declined in the Nordic countries over the past two decades concurrently with declining multiple birth rates.

WHAT IS KNOWN ALREADY

In the Nordic countries, the rate of twin pregnancies after ART has decreased from 30% in the early 1990s to 4-13% in 2014, following the implementation of elective single embryo transfer (SET). Consequently, preterm birth rates have declined substantially in ART pregnancies. However, whether the risk of CP, a known consequence of preterm birth, has decreased correspondingly is still unknown.

STUDY DESIGN, SIZE, DURATION

Retrospective register-based cohort study based on data on all singletons, twins, and higher-order multiples born in Denmark (birth year 1994-2010), Finland (1990-2010), and Sweden (1990-2014), corresponding to 111 844 ART children and 4 679 351 spontaneously conceived children.

PARTICIPANTS/MATERIAL, SETTING, METHODS

Data were obtained from a large Nordic cohort of children born after ART and spontaneous conception initiated by the Committee of Nordic ART and Safety-CoNARTaS. The CoNARTaS cohort was established by cross-linking national register data using the unique personal identification number, allocated to every citizen in the Nordic countries. Data from the National Medical Birth Registers, where information on maternal, obstetric, and perinatal outcomes is recorded, were cross-linked to data from the National ART- and Patients Registers to obtain information on fertility treatments and CP diagnoses. Relative risks of CP for ART compared to spontaneous conception were estimated as odds ratios from multivariate logistic regression analyses across all birth years, as well as for the following birth year categories: 1990-1993, 1994-1998, 1999-2002, 2003-2006, 2007-2010, and 2011-2014. Analyses were made for all children and for singletons and twins, separately.

MAIN RESULTS AND THE ROLE OF CHANCE

The main outcome measure was the relative odds of CP in different time periods for ART versus spontaneously conceived children. CP was diagnosed in 661 ART children and 16 478 spontaneously conceived children born between 1990 and 2014. In 1990-1993, the relative odds of CP were substantially higher in all ART children (adjusted odds ratio (aOR) 2.76 (95% CI 2.03-3.67)) compared with all spontaneously conceived children, while in 2011-2014, it was only moderately higher (aOR 1.39 (95% CI 1.01-1.87)). In singletons, the higher relative odds of CP in ART children diminished over time from 1990 to 1993 (aOR 2.02 (95% CI 1.22-3.14)) to 2003-2006 (aOR 1.18 (95% CI 0.91-1. 49)) and was not significantly increased for birth cohorts 2007-2010 and 2011-2014. For ART twins versus spontaneously conceived twins, the relative odds of CP was not statistically significantly increased throughout the study period.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of the study was a shorter follow-up time and younger age at first CP diagnosis for ART children compared with spontaneously conceived children. However, analyses ensuring a minimum of bias from differences in age at CP diagnosis and follow-up time confirmed the results, hence, we do not consider this to cause substantial bias.

WIDER IMPLICATIONS OF THE FINDINGS

A SET policy in ART treatments has the potential to reduce the increased risk of cerebral palsy in the ART population due to lower rates of multiple deliveries. At a time with high survival rates of frozen/thawed embryos, this study provides a strong argument against the continued use of multiple embryo transfer in most ART settings. Larger cohort studies including also the number of gestational sacs in early pregnancy will be preferable to show an effect of vanishing twins on the risk of CP in the ART population.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by grants from NordForsk (grant number 71450), Elsass Foundation (19-3-0444), the ALF-agreement (ALFGBG 70940), and The Research Fund of Rigshospitalet, Copenhagen University Hospital. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

O-076 Neurodevelopmental morbidity in children born after ART: a Nordic register study from the Committee of Nordic ART and Safety (CoNARTaS) group

Study question

Does the risk of neurodevelopmental disorders differ between singletons born after various assisted reproductive techniques (ART) and spontaneous conception (SC) until young adulthood?

Summary answer

ART children had a slightly increased rate of learning and motor functioning disorders, autism spectrum disorders (ASD), and ADHD and conduct disorders.

What is known already

Studies on the impact of ART on offspring have reported both increased risk and comparable incidences of neurodevelopmental disorders between ART and SC offspring. The most studied neurodevelopmental disorders with ART are autism spectrum disorders (ASD.) There is, however, no consensus on the risk of ASD for ART children. The risk for other neurodevelopmental disorders, like attention-deficit hyperactivity disorders (ADHD) or tic disorder among ART children, is also a debated issue, as studies are scarce.

Study design, size, duration

A Nordic register-based cohort study including all singleton live births (N = 5 076 444) after ART (n = 116 909) or SC (n = 4 959 535) between 1995 and 2014 in Denmark and Finland, 1995 and 2015 in Sweden; and 2005 and 2015 in Norway. Children with intellectual disability (ICD-10: F70-F79) are excluded. The children are followed up to young adulthood (the year 2014 in Denmark and Finland, and 2015 in Norway and Sweden).

Participants/materials, setting, methods

Offspring outcomes were defined as following ICD-10 diagnoses: learning and motor functioning disorders (F80-83), ASD (F84), ADHD and conduct disorders (F90-F92), and tic disorders/Tourette (F95). We calculated crude and adjusted hazard ratios (HR) for neurodevelopmental diagnoses using Cox regression. Adjustments were made for the country, maternal age at the delivery, parity, smoking, and maternal psychiatric morbidity.

Main results and the role of chance

The cumulative incidences of neurodevelopmental disorders in the cohort were 1.74% for F90-F92, 1.40% for F80-83, 0.66% for F84, and 0.22% for F95. In crude Cox-regression ART children had an increased likelihood during the follow-up of being diagnosed with F84 (HR 1.12 [95% CI 1.04-1.21]) and F95 (HR 1.21 [95% CI 1.06-1.38]), but not with F80-83 (HR 1.01 [95% CI 0.96-1.07]) or F90-92 (HR 0.82 [95% CI 0.77-0.86]). After adjustments the likelihood was increased for F80-83 (HR 1.20 [95% CI 1.13-1.27]), F84 (HR 1.12 [95% CI 1.03-1.24]), and F90-92 (HR 1.09 [95% CI 1.04-1.19]), but nor for F95 (HR 1.13 [95% CI 0.99-1.30]).

After adjustments, intracytoplasmic sperm injection children compared with in vitro fertilization children had similar likelihood during follow-up for F80-83 (1.06 [95% CI 0.89–1.25]), for F84 (HR 0.92 [95% CI 0.76–1.11]), for F90-92 (HR 0.96 [95% CI 0.83–1.12]), and for F95 (HR 1.16 [95% CI 0.83–1.63]).

After adjustments, frozen embryo transfer children compared with fresh embryo transfer children had similar likelihood during follow-up for F80-83 (HR 1.11 [95% CI 0.90–1.37]), F84 (HR 0.98 [95% CI 0.76–1.27]), F90-92 (HR 0.96 [95% CI 0.78–1.19]), and F95 (HR 0.83 [95% CI 0.51–1.35]).

Limitations, reasons for caution

There may be residual confounding by unknown or unmeasured confounders. We lack information on possible confounders like the reason and length of infertility, maternal substance use other than self-reported smoking status, paternal age, and parental somatic morbidity. Additional limitations are differences in registration practice and data availability between study countries.

Wider implications of the findings

This is the largest singleton cohort and the first multinational study on the risk for neurodevelopmental disorders among ART children. While the rate of some neurodevelopmental disorders was increased among ART children, the absolute risk was moderate. The type of ART did not associate with the incidence of neurodevelopmental disorders.

Trial registration number

ISRCTN11780826

Developmental Stage-Specific Effects of Parenting on Adolescents' Emotion Regulation: A Longitudinal Study From Infancy to Late Adolescence

The quality of parenting shapes the development of children's emotion regulation. However, the relative importance of parenting in different developmental stages, indicative of sensitive periods, has rarely been studied. Therefore, we formulated four hypothetical developmental timing models to test the stage-specific effects of mothering and fathering in terms of parental autonomy and intimacy in infancy, middle childhood, and late adolescence on adolescents' emotion regulation. The emotion regulation included reappraisal, suppression, and rumination. We hypothesized that both mothering and fathering in each developmental stage contribute unique effects to adolescents' emotion regulation patterns. The participants were 885 families followed from pregnancy to late adolescence. This preregistered study used data at the children's ages of 1 year, 7 to 8 years, and 18 years. At each measurement point, maternal and paternal autonomy and intimacy were assessed with self- and partner reports using the Subjective Family Picture Test. At the age of 18 years, adolescents' reappraisal and suppression were assessed using the Emotion Regulation Questionnaire and rumination using the Cognitive Emotion Regulation Questionnaire. Stage-specific effects were tested comparing structural equation models. Against our hypotheses, the results showed no effects of mothering or fathering in infancy, middle childhood, or late adolescence on adolescents' emotion regulation patterns. The results were consistent irrespective of both the reporter (i.e., self or partner) and the parental dimension (i.e., autonomy or intimacy). In addition to our main results, there were relatively low agreement between the parents in each other's parenting and descriptive discontinuity of parenting across time (i.e., configural measurement invariance). Overall, we found no support for the stage-specific effects of parent-reported parenting in infancy, middle childhood, or late adolescence on adolescents' emotion regulation. Instead, our findings might reflect the high developmental plasticity of emotion regulation from infancy to late adolescence.

Separating parental and treatment contributions to perinatal health after fresh and frozen embryo transfer in assisted reproduction: A cohort study with within-sibship analysis

BACKGROUND

Compared to naturally conceived children, adverse perinatal outcomes are more common among children born after assisted reproductive technology with fresh embryo transfer (fresh-ET) or frozen embryo transfer (frozen-ET). However, most previous studies could not adequately control for family confounding factors such as subfertility. We compared birth size and duration of pregnancy among infants born after fresh-ET or frozen-ET versus natural conception, using a within-sibship design to account for confounding by maternal factors.

METHODS AND FINDINGS

This registry-based cohort study with nationwide data from Denmark (1994-2014), Norway (1988-2015), and Sweden (1988-2015) consisted of 4,510,790 live-born singletons, 4,414,703 from natural conception, 78,095 from fresh-ET, and 17,990 from frozen-ET. We identified 33,056 offspring sibling groups with the same mother, conceived by at least 2 different conception methods. Outcomes were mean birthweight, small and large for gestational age, mean gestational age, preterm (<37 weeks, versus ≥37), and very preterm birth (<32 weeks, versus ≥32). Singletons born after fresh-ET had lower mean birthweight (-51 g, 95% CI -58 to -45, p < 0.001) and increased odds of small for gestational age (odds ratio [OR] 1.20, 95% CI 1.08 to 1.34, p < 0.001), while those born after frozen-ET had higher mean birthweight (82 g, 95% CI 70 to 94, p < 0.001) and increased odds of large for gestational age (OR 1.84, 95% CI 1.56 to 2.17, p < 0.001), compared to naturally conceived siblings. Conventional population analyses gave similar results. Compared to naturally conceived siblings, mean gestational age was lower after fresh-ET (-1.0 days, 95% CI -1.2 to -0.8, p < 0.001), but not after frozen-ET (0.3 days, 95% CI 0.0 to 0.6, p = 0.028). There were increased odds of preterm birth after fresh-ET (OR 1.27, 95% CI 1.17 to 1.37, p < 0.001), and in most models after frozen-ET, versus naturally conceived siblings, with somewhat stronger associations in population analyses. For very preterm birth, population analyses showed increased odds for both fresh-ET (OR 2.03, 95% CI 1.90 to 2.12, p < 0.001) and frozen-ET (OR 1.66, 95% CI 1.42 to 1.94, p < 0.001) compared with natural conception, but results were notably attenuated within siblings (OR 1.18, 95% CI 1.0 to 1.41, p = 0.059, and OR 0.92, 95% CI 0.67 to 1.27, p = 0.6, for fresh-ET and frozen-ET, respectively). Sensitivity analyses in full siblings, in siblings born within 3-year interval, by birth order, and restricting to single embryo transfers and blastocyst transfers were consistent with the main analyses. Main limitations were high proportions of missing data on maternal body mass index and smoking.

CONCLUSIONS

We found that infants conceived by fresh-ET had lower birthweight and increased odds of small for gestational age, and those conceived by frozen-ET had higher birthweight and increased odds of large for gestational age. Conception by either fresh-ET or frozen-ET was associated with increased odds of preterm birth. That these findings were observed within siblings, as well as in conventional multivariable population analyses, reduces the likelihood that they are explained by confounding or selection bias.

TRIAL REGISTRATION

ClinicalTrials.gov ISRCTN11780826.

High birth weight and large-for-gestational-age in singletons born after frozen compared to fresh embryo transfer, by gestational week: a Nordic register study from the CoNARTaS group

STUDY QUESTION

When do the differences in birth weights become apparent between singletons born after frozen embryo transfer (FET) and fresh embryo transfer (fresh ET)?

SUMMARY ANSWER

Mean birth weights after FET become significantly higher starting from gestational week (GW) 33 among boys and from GW 34 among girls.

WHAT IS KNOWN ALREADY

In recent years, there has been a steep rise in recorded FET treatments, enabling widespread use of elective single embryo transfer, thus reducing the risks associated with multiple gestations. However, singletons born after FET are heavier and there is a higher risk of large-for-gestational-age (LGA) (birth weight > 90 percentiles) compared to fresh ET. In contrast, risk of small-for-gestational-age (SGA, birth weight < 10 percentiles) is lower in singletons born after FET compared to fresh ET. The reasons, timing and consequences of these differences remain largely unclear. There is limited evidence about whether this difference in growth develops before the last trimester of pregnancy.

STUDY DESIGN, SIZE, DURATION

This retrospective Nordic register-based cohort study compared singletons born after FET (n = 17 500) to singletons born after fresh ET (n = 69 510) and natural conception (NC, n = 3 311 588). All live born singletons born between the years 2000 and 2015 in Denmark, Norway and Sweden at gestational age ≥22 weeks were included from the population-based Committee of Nordic ART and Safety (CoNARTaS) study population.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Children born after FET were compared to those born after fresh ET and NC for mean birth weight and proportion of LGA and SGA for each GW at birth. Chi-square test and tests for relative proportions were used to compare categorical variables and Student's t-test was used to compare continuous variables. Adjusted odds ratios (aORs) for LGA and SGA were calculated using logistic regressions, adjusting for year of birth, maternal age, parity, BMI, chronic hypertension, diabetes, smoking and offspring sex.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean birth weights were significantly higher after FET compared to fresh ET starting from GW 33 (range from 75 g to 228 g by week) for boys and starting from GW 34 (range from 90 g to 236 g by week) for girls. Boys born after FET had a significantly higher proportion of LGA (11.0-15.1%) at birth between GW 36 and 42, compared to those born after fresh ET (7.1-9.4%) (range from P < 0.001 to P = 0.048 by week). For girls born after FET, the difference was seen between GW 37 and 42 (10.6-13.4%) compared to those born after fresh ET (6.6-8.0%) (range from P < 0.001 to P = 0.009 by week).The proportion of SGA was significantly lower among boys born after FET (7.6-8.7%) compared to fresh ET (11.9-13.6%) between GW 36 and 42 (range from P < 0.001 to P = 0.016 by week). For girls born after FET, the difference was seen between GW 38 and 42 (7.0-9.3%) compared to those born after fresh ET (13.0-14.6%) (P < 0.001). The proportion of LGA (12.3-15.1%) was significantly higher for boys born after FET between GW 38 and 41 (P < 0.001) and for girls born after FET (12.6-13.4%) between GW 37 and 40 (range from P < 0.001 to P = 0.018 by week), compared to naturally conceived boys (9.7-9.9%) and girls (9.0-10.0%). All singletons born after FET had a higher risk of LGA compared to singletons born after fresh ET (aOR 1.87, 95% CI 1.76-1.98) and singletons born after NC (aOR 1.28, 95% CI 1.22-1.35).

LIMITATIONS, REASONS FOR CAUTION

There may be residual confounding factors that we were not able to control for, most importantly the causes of preterm birth, which may also influence foetal growth. A further limitation is that we have no knowledge on growth patterns between implantation and GW 22. Finally, the number of children born extremely preterm or post-term was limited even in this large study population.

WIDER IMPLICATIONS OF THE FINDINGS

This is, to date, the largest study on birth weights among preterm and term ART singletons with a population-based design and NC control group. The results suggest that the freeze-thaw process is associated with higher birthweights and greater risk of LGA at least in the last trimester of pregnancy. This is an important aspect of the safety profile of ART. More research is needed on the long-term outcome of these children.

STUDY FUNDING/COMPETING INTEREST(S)

The CoNARTaS collaboration has received the following funding: the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk [71450], the Central Norway Regional Health Authorities [46045000], the Norwegian Cancer Society [182356-2016], the Nordic Federation of Obstetrics and Gynaecology [NF13041, NF15058, NF16026 and NF17043], the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project) and the Research Council of Norway's Centre of Excellence funding scheme [262700]. None of the authors have any competing interests to declare.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

Obstetric and perinatal risks in 4601 singletons and 884 twins conceived after fresh blastocyst transfers: a Nordic study from the CoNARTaS group

STUDY QUESTION

Are obstetric and perinatal outcomes in pregnancies after fresh blastocyst transfer (BT) comparable with those born after fresh cleavage stage transfer (CT) and spontaneous conception (SC)?

SUMMARY ANSWER

Fresh BT is associated with a higher risk of placental and perinatal complications.

WHAT IS KNOWN ALREADY

BT optimizes the selection of top-quality embryos and increases pregnancy and live birth rates per transfer compared to CT. However, concerns have been raised as extended culture duration may increase obstetric complications and impair perinatal outcomes. Previous studies have shown a higher risk of preterm birth (PTB) among infants born after BT compared with CT. Pregnancies after BT are also prone to a higher risk of same-sex twins after single embryo transfer (SET).

STUDY DESIGN, SIZE, DURATION

A retrospective register-based cohort study used data from Denmark, Norway and Sweden including three cohorts: 56 557 singletons and 16 315 twins born after fresh IVF/ICSI cycles and 2 808 323 SC singletons in Denmark (birth years 1997-2014), Norway (2010-2015) and Sweden (2002-2015). Of the fresh IVF/ICSI singletons, 4601 were born after BT and 51 956 after CT. The twin cohort consisted of 884 fresh IVF/ICSI children born after BT and 15 431 fresh IVF/ICSI children born after CT.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were obtained from a large Nordic cohort of children born after ART and SC initiated by the Committee of Nordic ART and Safety (CoNARTaS). The CoNARTaS cohort was established by cross-linking National ART-, Medical Birth-, and National Patients Registers using the unique personal identification number, allocated to every citizen in the Nordic countries. Obstetric and perinatal outcomes after BT, CT and SC were compared using logistic regression analysis. For perinatal outcomes, we calculated gestational age based on the date of oocyte pick-up (OPU) and in sensitivity analyses on data from Denmark and Norway, we also calculated gestational age based on the second-trimester ultrasonography (US) scan. Risk of pregnancies with same-sex twins after SET was used as a proxy for risk of monozygotic twins. Adjustments were made for child's sex, birth year, parity (0 or >1), maternal age, body mass index, smoking, educational level, fertilization method (IVF/ICSI), the number of aspirated oocytes, SET and country. Information on educational level and the number of aspirated oocytes was not available for Norway. Children born after frozen embryo transfer were not included. The birth cohorts were restricted according to the year in which BT was introduced in the different countries.

MAIN RESULTS AND THE ROLE OF CHANCE

A higher risk of placenta previa was found in singleton pregnancies after BT compared with CT (adjusted odds ratio [aOR] 2.11 [95% CI 1.76; 2.52]). Singletons born after BT had a higher risk of PTB (aOR 1.14 [95% CI 1.01; 1.29]) compared with CT singletons, when estimated based on OPU. Furthermore, an altered male/female ratio (aOR 1.13 [95% CI 1.06; 1.21]) with more males following BT compared with CT was seen. Risk of same-sex twins after SET was higher after single BT compared with single CT (aOR 1.94 [95% CI 1.42; 2.60]).

LIMITATIONS, REASONS FOR CAUTION

Residual confounding cannot be excluded, in particular related to duration and cause of infertility that we could not adjust for due to lack of reliable data.

WIDER IMPLICATIONS OF THE FINDINGS

Extended embryo culture to the blastocyst stage has the potential to compromise obstetric and perinatal outcomes in fresh cycles. These results are important since an increasing number of IVF/ICSI treatments are performed as BT.

STUDY FUNDING/COMPETING INTEREST(S)

NORDFORSK (project no: 71450). The Research Fund of Rigshospitalet, Copenhagen University Hospital. ReproUnion Collaborative study, co-financed by the European Union, Interreg V ÖKS. Grants from Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (LUA/ALF 70940), Hjalmar Svensson Research Foundation. The Research Council of Norway through its Centres of Excellence funding scheme, project number 262700. None of the authors has any conflicts of interests to declare regarding this study.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

Monitoring serum estradiol levels in breast cancer patients during extended adjuvant letrozole treatment after five years of tamoxifen: a prospective trial

PURPOSE

To analyze whether monitoring serum estradiol (E2) levels using a highly sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) method may identify patients with AI failure with E2 levels below the lower limit of quantification (LLOQ) after schwitching from tamoxifen to letrozole.

METHODS

In a prospective study of breast cancer patients switching to letrozole treatment after previous tamoxifen, plasma estrogen levels were measured at baseline and after 3- and 12-months using LC-MS/MS.

RESULTS

Forty-six patients were classified postmenopausal and entered into the final analysis. Thirty-nine (85%) patients had three- and 12-month E2 concentrations below the LLOQ (5 pmol/L). In the seven patients classified as AI-failures during letrozole treatment, serum E2-MS level rose above 5 pmol/L at 3 months with a mean E2-MS 77.5 pmol/L or 12 months with a mean E2-MS 21 pmol/L. None of the baseline variables i.e., age at diagnosis, age at study entry, age at menarche, BMI, endometrial thickness, total ovarian volume, baseline FSH, E2-IA, or E2-MS were significantly associated with the risk of AI failure in logistic regression. E2 levels at baseline measured by E2-IA did not significantly correlate to the levels measured by E2-MS.

CONCLUSIONS

There is a relatively high risk of inadequate estrogen suppression in patients who switch from tamoxifen treatment to AIs. The use of sensitive and specific assays, such as LC-MS/MS methods, to monitor estrogen levels during AI treatment is essential to minimize the risk of a proceeding inefficient endocrine therapy.

Pregnancy and delivery outcomes in women with rectovaginal endometriosis treated either conservatively or operatively

OBJECTIVE

To study reproductive outcomes, and pregnancy and delivery complications after conservative or operative treatment of rectovaginal endometriosis during long-term follow-up.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

PATIENT(S)

Women with rectovaginal endometriosis referred to hospital due to any indication from 2004 to 2013 (N = 543) who were treated initially either conservatively (group CONS, n = 183), or operatively (OPER, n = 360) either with resection of rectovaginal nodule (RVR, n = 192) or with concomitant bowel resection (BR, n = 132).

INTERVENTION(S)

Conservative or operative management.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate, live-birth rate, and assessment of the complications during pregnancy and delivery.

RESULTS(S)

Between women in the CONS group or OPER group, no differences were found in either clinical pregnancy rate (56%, n = 102 vs. 50%, n = 181) or live-birth rate (48%, n = 87 vs. 42%, n = 153). Of the pregnancies, 64% (n = 65) and 49% (n = 89), respectively, started after medically assisted reproduction. No differences emerge in the subanalysis of women <40 years-old who wished to conceive. The most common pregnancy complication was preterm birth: 15% (n = 13) in the CONS group and 20% (n = 30) in the OPER group. The cesarean delivery rate also was high (46%, n = 40 vs. 49%, n = 76). Complications emerged in 21% (n = 10) versus 29% (n = 23) of vaginal deliveries and 45% (n = 18) versus 53% (n = 40) of cesarean deliveries. The most common delivery complication was excessive bleeding. The follow-up period was 4.9 years in the CONS group and 5.6 years in the OPER group.

CONCLUSION(S)

Women with rectovaginal endometriosis have comparable and good reproductive prognosis regardless of the treatment method.

Perinatal and maternal outcome after vitrification of blastocysts: a Nordic study in singletons from the CoNARTaS group

STUDY QUESTION

Is transfer of vitrified blastocysts associated with higher perinatal and maternal risks compared with slow-frozen cleavage stage embryos and fresh blastocysts?

SUMMARY ANSWER

Transfer of vitrified blastocysts is associated with a higher risk of preterm birth (PTB) when compared with slow-frozen cleavage stage embryos and with a higher risk of a large baby, hypertensive disorders in pregnancy (HDPs) and postpartum hemorrhage (PPH) but a lower risk of placenta previa when compared with fresh blastocysts.

WHAT IS KNOWN ALREADY

Transfer of frozen-thawed embryos (FETs) plays a central role in modern fertility treatment, limiting the risk of ovarian hyperstimulation syndrome and multiple pregnancies. Following FET, several studies report a lower risk of PTB, low birth weight (LBW) and small for gestational age (SGA) yet a higher risk of fetal macrosomia and large for gestational age (LGA) compared with fresh embryos. In recent years, the introduction of new freezing techniques has increased treatment success. The slow-freeze technique combined with cleavage stage transfer has been replaced by vitrification and blastocyst transfer. Only few studies have compared perinatal and maternal outcomes after vitrification and slow-freeze and mainly in cleavage stage embryos, with most studies indicating similar outcomes in the two groups. Studies on perinatal and maternal outcomes following vitrified blastocysts are limited.

STUDY DESIGN, SIZE, DURATION

This registry-based cohort study includes singletons born after frozen-thawed and fresh transfers following the introduction of vitrification in Sweden and Denmark, in 2002 and 2009, respectively. The study includes 3650 children born after transfer of vitrified blastocysts, 8123 children born after transfer of slow-frozen cleavage stage embryos and 4469 children born after transfer of fresh blastocysts during 2002-2015. Perinatal and maternal outcomes in singletons born after vitrified blastocyst transfer were compared with singletons born after slow-frozen cleavage stage transfer and singletons born after fresh blastocyst transfer. Main outcomes included PTB, LBW, macrosomia, HDP and placenta previa.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were obtained from the CoNARTaS (Committee of Nordic ART and Safety) group. Based on national registries in Sweden, Finland, Denmark and Norway, the CoNARTaS cohort includes all children born after ART treatment in public and private clinics 1984-2015. Outcomes were assessed with logistic multivariable regression analysis, adjusting for the country and year of birth, maternal age, body mass index, parity, smoking, parental educational level, fertilisation method (IVF/ICSI), single embryo transfer, number of gestational sacs and the child's sex.

MAIN RESULTS AND THE ROLE OF CHANCE

A higher risk of PTB (<37 weeks) was noted in the vitrified blastocyst group compared with the slow-frozen cleavage stage group (adjusted odds ratio, aOR [95% CI], 1.33 [1.09-1.62]). No significant differences were observed for LBW (<2500 g), SGA, macrosomia (≥4500 g) and LGA when comparing the vitrified blastocyst with the slow-frozen cleavage stage group. For maternal outcomes, no significant difference was seen in the risk of HDP, placenta previa, placental abruption and PPH in the vitrified blastocyst versus the slow frozen cleavage stage group, although the precision was limited.When comparing vitrified and fresh blastocysts, we found higher risks of macrosomia (≥4500 g) aOR 1.77 [1.35-2.31] and LGA aOR 1.48 [1.18-1.84]. Further, the risks of HDP aOR 1.47 [1.19-1.81] and PPH aOR 1.68 [1.39-2.03] were higher in singletons born after vitrified compared with fresh blastocyst transfer while the risks of SGA aOR 0.58 [0.44-0.78] and placenta previa aOR 0.35 [0.25-0.48] were lower.

LIMITATIONS, REASONS FOR CAUTION

Since vitrification was introduced simultaneously with blastocyst transfer in Sweden and Denmark, it was not possible to explore the effect of vitrification per se in this study.

WIDER IMPLICATIONS OF THE FINDINGS

The results from the change of strategy to vitrification of blastocysts are reassuring, indicating that the freezing technique per se has no major influence on the perinatal and maternal outcomes. The higher risk of PTB may be related to the extended embryo culture rather than vitrification.

STUDY FUNDING/COMPETING INTEREST(S)

The study is part of the ReproUnion Collaborative study, co-financed by the European Union, Interreg V ÖKS. The study was also financed by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF agreement (LUA/ALF 70940), Hjalmar Svensson Research Foundation and NordForsk (project 71 450). There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

Puberty problems among ART children born 1985-2015 in the Nordic countries – CoNARTaS cohort data

Background

Children born after ART (Assisted reproductive technology) are known to be at increased risk for adverse outcomes, but there are little data on health of older children. The aim of this study is to examine puberty related outcomes of ART children as available in existing health care registers, using Nordic data.

Methods

The CoNARTaS cohort contains data on 121 746 ART children and 6 538 411 naturally conceived children born in Denmark (1994-2014), Finland (1990-2014), Norway (2002-2015) and Sweden (1985-2015). All data were obtained from national health registries, disease-specific quality registries and other nationwide databases. Puberty problems were defined by using ICD-10 codes and classified as any problems, late and early puberty and unspecified problems. Cox regression adjusted for maternal age, parity, plurality, maternal diabetes and maternal smoking were made, separately for girls and boys.

Results

36 508 children had diagnoses related to puberty problems, of which 591 were ART-children including IVF (in vitro fertilization) and ICSI (intra cytoplasmic sperm injection). In total, ART children had increased risks for any pubertal problems (adjusted HR 1.60, 95% CI: 1.47-1.74), late puberty (1.57, 95% CI: 1.31-1.89) and early puberty (1.63, 95% CI: 1.46-1.82). The effect was similar for girls (1.61, 95% CI: 1.46-1.78) and boys (1.55, 95% CI: 1.33-1.81), but girls had more diagnoses related to early puberty (66.2%) and boys with late puberty (48.8%). ICSI was associated with higher risk (2.01, 95% CI 1.74-2.31) than IVF (1.46, 95% CI: 1.30-1.65), but the difference between fresh and frozen embryo transfer remained statistically insignificant.

Conclusions

Both girls and boys born after ART had the increased risk for pubertal problems. However, we could not adjust for all possible confounders such as infertility diagnoses or drugs used in ART. More studies are needed to confirm the findings and to find out reasons for the increased risks.

Key messages

Both girls and boys born after ART had the increased risk for pubertal problems. More studies are needed to confirm the findings and to find out reasons for the increased risks.

Time trends in placenta-mediated pregnancy complications after assisted reproductive technology in the Nordic countries

BACKGROUND

The use of assisted reproductive technology is increasing worldwide and conception after assisted reproduction currently comprises 3%-6% of birth cohorts in the Nordic countries. The risk of placenta-mediated pregnancy complications is greater after assisted reproductive technology compared with spontaneously conceived pregnancies. Whether the excess risk of placenta-mediated pregnancy complications in pregnancies following assisted reproduction has changed over time, is unknown.

OBJECTIVES

To investigate whether time trends in risk of pregnancy complications (hypertensive disorders in pregnancy, placental abruption and placenta previa) differ for pregnancies after assisted reproductive technology compared with spontaneously conceived pregnancies during 3 decades of assisted reproduction treatment in the Nordic countries.

STUDY DESIGN

In a population-based cohort study, with data from national health registries in Denmark (1994-2014), Finland (1990-2014), Norway (1988-2015) and Sweden (1988-2015), we included 6,830,578 pregnancies resulting in delivery. Among these, 146,998 (2.2%) were pregnancies after assisted reproduction (125,708 singleton pregnancies, 20,668 twin pregnancies and 622 of higher order plurality) and 6,683,132 (97.8%) pregnancies were conceived spontaneously (6,595,185 singleton pregnancies, 87,106 twin pregnancies and 1,289 of higher order plurality). We used logistic regression with post-estimation to estimate absolute risks and risk differences for each complication. We repeated analyses for singleton and twin pregnancies, separately. In subsamples with available information, we also adjusted for maternal body mass index, smoking during pregnancy, previous cesarean delivery, culture duration, and cryopreservation.

RESULTS

The risk of each placental complication was consistently greater in pregnancies following assisted reproductive technology compared with spontaneously conceived pregnancies across the study period, except for hypertensive disorders in twin pregnancies, where risks were similar. Risk of hypertensive disorders increased over time in twin pregnancies for both conception methods, but more strongly for pregnancies following assisted reproductive technology (risk difference, 1.73 percentage points per 5 years; 95% confidence interval, 1.35-2.11) than for spontaneously conceived twins (risk difference, 0.75 percentage points; 95% confidence interval, 0.61-0.89). No clear time trends were found for hypertensive disorders in singleton pregnancies. Risk of placental abruption decreased over time in all groups. Risk differences were -0.16 percentage points (95% confidence interval, -0.19 to -0.12) and -0.06 percentage points (95% confidence interval, -0.06 to -0.05) for pregnancies after assisted reproduction and spontaneously conceived pregnancies, respectively, for singletons and multiple pregnancies combined. Over time, the risk of placenta previa increased in pregnancies after assisted reproduction among both singletons (risk difference, 0.21 percentage points; 95% confidence interval, 0.14-0.27) and twins (risk difference, 0.30 percentage points; 95% confidence interval, 0.16-0.43), but remained stable in spontaneously conceived pregnancies. When adjusting for culture duration, the temporal increase in placenta previa became weaker in all groups of assisted reproductive technology pregnancies, whereas adjustment for cryopreservation moderately attenuated trends in assisted reproductive technology twin pregnancies.

CONCLUSIONS

The risk of placenta-mediated pregnancy complications following assisted reproductive technology remains higher compared to spontaneously conceived pregnancies, despite declining rates of multiple pregnancies. For hypertensive disorders in pregnancy and placental abruption, pregnancies after assisted reproduction follow the same time trends as the background population, whereas for placenta previa, risk has increased over time in pregnancies after assisted reproductive technology.

Imprinting disorders in children born after ART: a Nordic study from the CoNARTaS group

STUDY QUESTION:

Is the risk of imprinting disorders increased in children conceived after

SUMMARY ANSWER:

We found an adjusted odds ratio (AOR) of 2.84 [95% CI: 1.34–6.01] for Beckwith–Wiedemann syndrome in ART children, while the risk of Prader–Willi syndrome, Silver–Russell syndrome or Angelman syndrome was not increased in children conceived after ART.

WHAT IS KNOWN ALREADY:

Earlier studies, most of them small, have suggested an association between ART and imprinting disorders.

STUDY DESIGN, SIZE, DURATION:

This was a binational register-based cohort study. All children conceived by ART in Denmark (n = 45 393, born between 1994 and 2014) and in Finland (n = 29 244, born between 1990 and 2014) were identified. The full background populations born during the same time periods in the two countries were included as controls. Odds ratios of imprinting disorders in ART children compared with naturally conceived (NC) children were calculated. The median follow-up time was 8 years and 9 months for ART children and 11 years and 9 months for NC children.

PARTICIPANTS/MATERIALS, SETTING, METHODS:

From the national health registries in Denmark and Finland, we identified all children diagnosed with Prader–Willi syndrome (n = 143), Silver–Russell syndrome (n = 69), Beckwith–Wiedemann syndrome (n = 105) and Angelman syndrome (n = 72) born between 1994/1990 and 2014, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE:

We identified a total of 388 children diagnosed with imprinting disorders; 16 of these were conceived after ART. The overall AOR for the four imprinting disorders in ART children compared with NC children was 1.35 [95% CI: 0.80–2.29], but since eight ART children were diagnosed with Beckwith–Wiedemann syndrome, the AOR for this specific imprinting disorder was 2.84 [95% CI: 1.34–6.01]. The absolute risk of Beckwith–Wiedemann syndrome in children conceived after ART was still low: 10.7 out of 100 000 newborns. The risks of Prader–Willi syndrome, Silver–Russell syndrome and Angelman syndrome were not increased in children conceived after ART.

LIMITATIONS, REASONS FOR CAUTION:

Imprinting disorders are rare events and our results are based on few ART children with imprinting disorders. The aetiology is complex and only partly clarified, and the clinical diagnoses are challenged by a broad phenotypic spectrum.

WIDER IMPLICATIONS OF THE FINDINGS:

In the existing studies, results on the risk of imprinting disorders in children conceived after ART are ambiguous. This study adds that the risk of imprinting disorders in ART children is very small and perhaps restricted to Beckwith–Wiedemann syndrome.

STUDY FUNDING/COMPETING INTEREST(S):

This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (grant number: 71450), the Nordic Federation of Obstetrics and Gynecology (grant numbers: NF13041, NF15058, NF16026 and NF17043) and the Interreg Öresund-Kattegat-Skagerak European Regional Development Fund (ReproUnion project). The authors have no conflicts of interest related to this work.

TRIAL REGISTRATION NUMBER:

N/A

Plasma pentraxin 3 is higher in early ovarian hyperstimulation syndrome than in uncomplicated in vitro fertilization cycle of high-risk women

Purpose

Pentraxin 3 (PTX3) is a locally secreted, quicker responsive pro-inflammatory protein than C-reactive protein (CRP). We evaluated the value of PTX3 in the prediction of ovarian hyperstimulation syndrome (OHSS), a severe complication of in vitro fertilization (IVF).

Methods

This two-year prospective follow-up study included 27 women with uncomplicated IVF-cycles (IVF group) and 31 patients diagnosed with moderate or severe early OHSS (OHSS group). PTX3 was analysed from follicular fluid (FF) and serial blood samples with enzyme-linked immunoassay and CRP with particle-enhanced immunoturbidimetric assay. The value of PTX3 and CRP in detecting OHSS was examined with receiver operating characteristic (ROC) curve analysis and expressed as the area under the curve (AUC).

Results

The circulating PTX3 level peaked at two days after oocyte pick-up (OPU2), and in the OHSS group the level was 1.9 times higher (P = 0.006) than in the IVF group. However, in ROC curve analysis PTX3 (AUC 0.79, best cut off 1.1 µg/L) was not superior to CRP (AUC 0.87; best cut off 9.5 mg/L) in predicting early OHSS. In the IVF group, the FF-PTX3 concentration was 15–20 times higher than in the plasma. PTX3 level at OPU2 correlated with the number of punctured follicles (r = 0.56, n = 22, P = 0.006). Triggering with human chorionic gonadotrophin or early pregnancy had no effect on PTX3 level.

Conclusion

The elevated PTX3 concentration in OHSS at OPU2, when freeze-all embryos strategy is still possible to consider, indicates that PTX3 level could provide additional benefit in the risk assessment for early OHSS.

Low anti-Müllerian hormone level is not a risk factor for early pregnancy loss in IVF/ICSI treatment

STUDY QUESTION

Is a low (&lt;1.0 μg/L) or moderately low (1.0–1.9 μg/L) serum anti-Müllerian hormone (AMH) level a risk factor for early pregnancy loss in IVF/ICSI with a fresh or frozen-thawed embryo transfer (ET)?

SUMMARY ANSWER

A low or moderately low serum AMH level does not associate with miscarriage, non-visualized pregnancy loss or overall early pregnancy loss rate in the IVF/ICSI treatment.

WHAT IS KNOWN ALREADY

Low AMH predicts poor ovarian response and small oocyte yield in IVF/ICSI treatment, but its value in the evaluation of live birth rate (LBR) is modest. Little is known about the risk of early pregnancy loss in ART among women with low AMH.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study on 1383 women undergoing their first oocyte retrieval for IVF/ICSI in Helsinki University Hospital in Helsinki, Finland, between 2012 and 2016, with all associated fresh (n = 1315) and frozen-thawed (n = 1418) ET cycles finished by August 2018. AMH was measured within 12 months before the IVF/ICSI stimulation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of all the women, 235 (17.0%) had low (&lt;1.0 μg/L), 278 (20.1%) had moderately low (1.0–1.9 μg/L) and 870 (62.9%) had normal (≥2.0 μg/L) AMH. The primary outcomes were miscarriage, non-visualized pregnancy loss and early pregnancy loss (miscarriage and non-visualized pregnancy loss combined) after fresh or frozen-thawed ET. The impact of AMH on these outcomes was calculated in three populations: among all women who became pregnant, among women with AMH ≤6.0 μg/L and in a population weighted by the inverse probability of becoming pregnant (inverse probability weighting, IPW). The impact of AMH was also assessed on the secondary outcomes, cumulative pregnancy rate (cPR) and cumulative live birth rate (cLBR) across all ET cycles in the woman’s first IVF/ICSI. Potential confounders (the woman’s age, overweight, smoking, history of endometriosis and underlying medical conditions) adjusted the final results.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 1123 pregnancies, 285 (25.4%) ended in non-visualized pregnancy loss and 143 (12.7%) in miscarriage. The LBR was 24.6% per ET (673/2733). Low or moderately low AMH, compared with normal AMH, did not associate with miscarriage or non-visualized pregnancy loss in analyses among all women who became pregnant (adjusted relative risk (RR) for miscarriage vs live birth, 0.70 and 95% CI 0.42–1.17 in low AMH and adjusted RR, 1.00 and 95% CI, 0.68–1.49 in moderately low AMH; adjusted RR for non-visualized pregnancy loss vs live birth, 0.90 and 95% CI, 0.65–1.23 in low AMH and adjusted RR, 1.09 and 95% CI 0.85–1.41 in moderately low AMH), nor did low or moderately low AMH associate with the overall early pregnancy loss rate (adjusted RR for early pregnancy loss vs live birth, 0.86 and 95% CI, 0.68–1.10 in low AMH and adjusted RR, 1.01 and 95% CI, 0.86–1.27 in moderately low AMH). Results remained similar after restricting the analysis to women with AMH ≤6.0 μg/L. Women with low or moderately low AMH had fewer pregnancies and live births than women with normal AMH in their first IVF/ICSI (cPR/cLBR in women with low AMH 50.6/34.0%, moderately low AMH 59.0/36.3% and normal AMH 68.3/49.2%). When the lower probability for pregnancy was considered by using IPW, women with low or moderately low AMH did not have a higher risk for miscarriage, non-visualized pregnancy loss or overall early pregnancy loss compared with women with normal AMH.

LIMITATIONS, REASONS FOR CAUTION

The number of miscarriages in women with low AMH was moderately small, limiting the power of the study. The real-world clinical setting of the study restricted the ability to control for all factors causing selection bias.

WIDER IMPLICATIONS OF THE FINDINGS

The cLBR was higher among women with normal AMH than among women with low or moderately low AMH in their first IVF/ICSI treatment because these women had more oocytes and embryos. Women with low or moderately low AMH did not have an increased risk for early pregnancy loss. This information is reassuring for couples and useful in counseling. These results are also valuable when assessing the overall effectiveness of IVF/ICSI treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Research funds from Helsinki University Hospital (no. TYH2018232), Hyvinkää Hospital (no. M3080TUT18) and the Emil Aaltonen Foundation for P.P. Grants from the Paulo Foundation and the Finnish Medical Foundation for H.H. The authors report no conflicts of interest.

TRIAL REGISTRATION NUMBER

HUS/138/2017.

Prevalence and persistence of Chlamydia trachomatis-specific antibodies after occasional and recurrent infections

OBJECTIVES

Population-based Chlamydia trachomatis seroepidemiological studies help to identify trends in chlamydia infection. However, an improved understanding of the antibody response to infection is required when using serology to estimate cumulative incidence. Thus, the objectives of this longitudinal, retrospective, biobank-based study were to assess the appearance and persistence of C. trachomatis major outer membrane protein (MOMP)-specific serum IgG antibodies after infection and to evaluate the role of antibodies in providing protective immunity against recurrent infection.

METHODS

Data of notified C. trachomatis infections in Finland were obtained from the National Infectious Diseases Register. Serum samples were acquired from the Finnish Maternity Cohort. 411 women with single chlamydia infection and 62 women with recurrent infections, and for whom suitable paired serum samples were available, were included in the study. Antibody appearance, persistence after infection and the impact of recurrent infections were evaluated. IgG antibodies specific for MOMP were measured from serum using an ELISA method.

RESULTS

Anti-C. trachomatis MOMP-specific IgG antibodies were detected in 65.5% (269/411) of women within 3 months of notification of infection. In the absence of recurrent infection, seroprevalence declined to 34.5% (142/411) 3-10 years after the initial infection. The serum antibody levels at baseline correlated positively with seroprevalence at follow-up. Reinfection boosted the humoral immune response by increasing seroprevalence and the serum antibody levels. Seroprevalence within 3 months after first notification of infection was 65.5% (19/29) in women who were later diagnosed with recurrent infection, comparable with women with single notification of infection (65.5%, 269/411).

CONCLUSIONS

Approximately one-third of women with single notification of chlamydia infection remain seropositive 3-10 years after the initial infection. The concentration of antibodies remained stable during the follow-up. Recurrent infection boosted the humoral immune response, but reinfection occurred despite the presence of pre-existing antibodies.

Mortality of midlife women with surgically verified endometriosis—a cohort study including 2.5 million person-years of observation

STUDY QUESTION

Is all-cause and cause-specific mortality increased among women with surgically verified endometriosis?

SUMMARY ANSWER

The all-cause and cause-specific mortality in midlife was lower throughout the follow-up among women with surgically verified endometriosis compared to the reference cohort.

WHAT IS KNOWN ALREADY

Endometriosis has been associated with an increased risk of comorbidities such as certain cancers and cardiovascular diseases. These diseases are also common causes of death; however, little is known about the mortality of women with endometriosis.

STUDY DESIGN, SIZE, DURATION

A nationwide retrospective cohort study of women with surgically verified diagnosis of endometriosis was compared to the reference cohort in Finland (1987–2012). Follow-up ended at death or 31 December 2014. During the median follow-up of 17 years, 2.5 million person-years accumulated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Forty-nine thousand nine hundred and fifty-six women with at least one record of surgically verified diagnosis of endometriosis in the Finnish Hospital Discharge Register between 1987 and 2012 were compared to a reference cohort of 98 824 age- and municipality-matched women. The age (mean ± standard deviation) of the endometriosis cohort was 36.4 ± 9.0 and 53.6 ± 12.1 years at the beginning and at the end of the follow-up, respectively. By using the Poisson regression models the crude and adjusted all-cause and cause-specific mortality rate ratios (MRR) and 95% confidence intervals (CI) were assessed. Calendar time, age, time since the start of follow-up, educational level, and parity adjusted were considered in the multivariate analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1656 and 4291 deaths occurred in the endometriosis and reference cohorts, respectively. A lower all-cause mortality was observed for the endometriosis cohort (adjusted MRR, 0.73 [95% CI 0.69 to 0.77])—there were four deaths less per 1000 women over 10 years. A lower cause-specific mortality contributed to this: the adjusted MRR was 0.88 (95% CI 0.81 to 0.96) for any cancer and 0.55 (95% CI 0.47 to 0.65) for cardiovascular diseases, including 0.52 (95% CI 0.42 to 0.64) for ischemic heart disease and 0.60 (95% CI 0.47 to 0.76) for cerebrovascular disease. Mortality due to alcohol, accidents and violence, respiratory, and digestive disease-related causes was also decreased.

LIMITATIONS, REASONS FOR CAUSATION

These results are limited to women with endometriosis diagnosed by surgery. In addition, the study does not extend into the oldest age groups. The results might be explained by the characteristics and factors related to women’s lifestyle, and/or increased medical attention and care received, rather than the disease itself.

WIDER IMPLICATIONS OF THE FINDINGS

These reassuring data are valuable to women with endometriosis and to their health care providers. Nonetheless, more studies are needed to address the causality.

STUDY FUNDING/COMPETING INTEREST

This research was funded by the Hospital District of Helsinki and Uusimaa and The Finnish Medical Foundation. None of the authors report any competing interest in relation to the present work; all the authors have completed the disclosure form.

Hormone profiling, including anti-Müllerian hormone (AMH), for the diagnosis of polycystic ovary syndrome (PCOS) and characterization of PCOS phenotypes

Objective was to evaluate serum anti-Müllerian hormone (AMH) levels in polycystic ovary syndrome (PCOS) and in its different phenotypes in relation to clinical, endocrine and metabolic parameters using a new automated VIDAS^® method and to compare it with the Gen II method. Study design was multi-center study including 319 PCOS women and 109 healthy controls. Serum AMH levels measured using VIDAS^® were significantly higher in PCOS women than controls (p < .001), and they correlated with those measured using the AMH Gen II method. An AMH cutoff value of 42.1 pmol/L distinguished PCOS women from controls with 67% sensitivity and 83% specificity. The PCOS women with three Rotterdam criteria or hyperandrogenism displayed significantly higher AMH levels compared with those with two Rotterdam criteria or normoandrogenism. In PCOS, AMH levels correlated positively with luteinizing hormone (LH), androgen and sex hormone-binding globulin (SHBG) levels and negatively with BMI, abdominal obesity, follicle-stimulating hormone (FSH), fasting glucose and insulin, and insulin resistance. In conclusion, AMH evaluated using the VIDAS^® method distinguished PCOS patients from healthy controls relatively well, especially in those with more severe phenotypes. Further studies are needed to establish whether AMH measurements can distinguish PCOS patients with different metabolic risk factors.

A cohort study of 49 933 women with surgically verified endometriosis: Increased incidence of breast cancer below the age of 40

INTRODUCTION

The association between endometriosis and breast cancer is unclear. We assessed the risk of breast cancer in women with surgically verified endometriosis, with special focus on the age at cancer diagnosis, time from endometriosis diagnosis and breast cancer histology.

MATERIAL AND METHODS

All women with first endometriosis-associated diagnoses occurring concomitantly with relevant surgical codes during 1987-2012 were retrieved from the Finnish Hospital Discharge Register in Finland. Breast cancers diagnosed after the endometriosis diagnosis were identified from the Finnish Cancer Registry. The Finnish female population served as the reference. The endometriosis cohort consisted of 49 933 women (23 210 cases of ovarian, 20 187 peritoneal and 2372 deep infiltrating endometriosis). The outcome measure was the standardized incidence ratio (SIR) with 95% confidence interval (95% CI) of breast cancer calculated for the whole cohort and for the subtypes of endometriosis, stratified by the age at breast cancer diagnosis, histology and time from endometriosis diagnosis.

RESULTS

The overall risk of breast cancer (1555 cases) was similar to the reference population (SIR 0.99; 95% CI 0.94-1.03), did not differ in types of endometriosis, and was similar for ductal and lobular breast cancer. However, the SIR of breast cancer was increased in the age group of 20-29 years (SIR 4.44; 95% CI 2.22-7.94) and in the age group of 30-39 years (SIR 1.28; 95% CI 1.03-1.57). The risk of in situ breast cancer (170 cases) was increased in the entire endometriosis cohort (SIR 1.25; 95% CI 1.07-1.44).

CONCLUSIONS

The overall risk of breast cancer in women with surgically verified endometriosis was similar to that of general population. However, the risk of breast cancer at young age was increased. Young women with surgically verified endometriosis represent highly symptomatic patients with more frequent surgeries and additional therapies that might also contribute to the risk of breast cancer.

Premature ovarian insufficiency and early depletion of the ovarian reserve in the monogenic Mulibrey nanism disorder

STUDY QUESTION

What is the timing of onset and clinical course of premature ovarian insufficiency (POI) in patients with Mulibrey nanism (MUL), a monogenic disorder caused by mutations of the peroxisomal TRIM37 gene?

SUMMARY ANSWER

The number of ovarian follicles is highly reduced already in infant and young MUL girls and the majority of them will have early depletion of follicles resulting in clinical and biochemical signs of POI.

WHAT IS KNOWN ALREADY

Both female and male patients with MUL show failure of sexual maturation, signs of hypogonadism and infertility.

STUDY DESIGN, SIZE, DURATION

We studied the gonadal function, pubertal development and ovarian reserve in 33 MUL patients aged 5.1-47.3 years (median age 22.3) at the end of observation. The patients were followed between 2004 and 2014 and 19 pubertal or postpubertal patients were enrolled in a cross-sectional study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The period of postnatal activation of the hypothalamic-pituitary-gonadal axis (minipuberty), pubertal development and menstrual history were assessed longitudinally. The cross-sectional study included gynecological examination, analysis of reproductive hormones and ultrasonography with evaluation of ovarian volume and antral follicle count.

MAIN RESULTS AND THE ROLE OF CHANCE

Infant girls experienced a transient minipuberty with a high FSH surge. In childhood, gonadotropins were normal or slightly elevated but began to rise to hypergonadotropic levels in prepuberty. Anti-Müllerian hormone (AMH) levels remained undetectable or low throughout childhood. The onset of puberty occurred spontaneously and the median age at menarche was 12.5 years. Of the patients, 54% never attained regular menses and 10 years from menarche, only 8% of the women menstruated regularly. In the cross-sectional study, none of the patients had normal ovarian morphology under ultrasonography. Ovaries were hypoplastic and 82% had no or fewer than two visible antral follicles. AMH levels were undetectable in the vast majority (89%).

LIMITATIONS, REASONS FOR CAUTION

The Finnish MUL patients genotypically form a homogenous group and therefore it is possible, that different TRIM37 mutations lead to different hypogonadal phenotypes. However, to date there is no known genotype-phenotype correlation in MUL.

WIDER IMPLICATIONS OF THE FINDINGS

In MUL, AMH is a useful marker of ovarian function. MUL should be added to the list of syndromes associated with POI and correspondingly, TRIM37 should be added to the list of genes associated with POI. To our knowledge, TRIM37 is the first known gene coding for a peroxisomal membrane protein associated with female gonadal failure and infertility. Elucidating the role of syndromic genes in reproduction may aid in a greater understanding of ovarian biology.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Finnish Foundation for Pediatric Research, Finska Läkaresällskapet, the Sigrid Jusélius Foundation and Helsinki University Hospital Research Funds. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Single embryo transfer: Why and how to identify the embryo with the best developmental potential

Multiple pregnancies with higher risk of preterm birth and the associated higher morbidity have been a major obstacle from the early days of in vitro fertilization. A good strategy to avoid multiple pregnancies is elective single embryo transfer and cryopreservation of spare embryos. Important factors in adopting this strategy are good counselling of the patients and the selection of embryos with high implantation potential. Technical advances in embryo selection have been described during recent years, time lapse monitoring and genetic assessment of the embryos being the most important achievements. With these studies we have gained new information on early embryos. However, at present, there is insufficient evidence to recommend the routine use of these new techniques. The ultimate goal of infertility treatment is a healthy baby.

Heterogeneity of gestational diabetes (GDM) and challenges in developing a GDM risk score

AIMS

Gestational diabetes (GDM) affects a growing number of women and identification of individuals at risk, e.g., with risk prediction models, would be important. However, the performance of GDM risk scores has not been optimal. Here, we assess the impact of GDM heterogeneity on the performance of two top-rated GDM risk scores.

METHODS

This is a substudy of the RADIEL trial-a lifestyle intervention study including women at high GDM risk. We assessed the GDM risk score by Teede and that developed by Van Leeuwen in our high-risk cohort of 510 women. To investigate the heterogeneity of GDM, we further divided the women according to GDM history, BMI, and parity. With the goal of identifying novel predictors of GDM, we further analyzed 319 women with normal glucose tolerance in the first trimester.

RESULTS

Both risk scores underestimated GDM incidence in our high-risk cohort. Among women with a BMI ≥ 30 kg/m² and/or previous GDM, 49.4% developed GDM and 37.4% received the diagnosis already in the first trimester. Van Leeuwen score estimated a 19% probability of GDM and Teede succeeded in risk identification in 61%. The lowest performance of the risk scores was seen among the non-obese women. Fasting plasma glucose, HbA_1c, and family history of diabetes were predictors of GDM in the total study population. Analysis of subgroups did not provide any further information.

CONCLUSIONS

Our findings suggest that the marked heterogeneity of GDM challenges the development of risk scores for detection of GDM.