Infant and maternal health monitoring using a combined Nordic database on ART and safety

Long-term outcomes for children conceived by assisted reproductive technology

Worldwide, more than 10 million children have been born after assisted reproduction technology (ART), comprising up to 7.9% of children born in Europe and up to 5.1 % of children born in the US in 2018. The short-term outcome for children born after ART is well-known from numerous publications, with higher rates of preterm birth and low birth weight in children born after fresh embryo transfer and higher rates of large for gestational age and high birth weight in children born after frozen embryo transfer compared with children born after spontaneous conception. Higher rates of birth defects in children born after ART have also been shown consistently over time. Studies on long-term health outcomes after ART are scarcer but suggest an increased risk of altered blood pressure and cardiovascular function in children born after ART. In this review, we summarize long-term health outcomes in children born after ART and discuss whether the increased health risks are associated with intrinsic maternal or paternal factors related to subfertility or ART treatments per se. Finally, we speculate where the future will bring us regarding ART treatment strategies and the safety of the mother and child.

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.

The Swedish medical birth register during five decades: documentation of the content and quality of the register

Pregnancy-related factors are important for short- and long-term health in mothers and offspring. The nationwide population-based Swedish Medical Birth Register (MBR) was established in 1973. The present study describes the content and quality of the MBR, using original MBR data, Swedish-language and international publications based on the MBR.The MBR includes around 98% of all births in Sweden. From 1982 onwards, the MBR is based on prospectively recorded information in standardized antenatal, obstetric, and neonatal records. When the mother and infant are discharged from hospital, this information is forwarded to the MBR, which is updated annually. Maternal data include information from first antenatal visit on self-reported obstetric history, infertility, diseases, medication use, cohabitation status, smoking and snuff use, self-reported height and measured weight, allowing calculation of body mass index. Birth and neonatal data include date and time of birth, mode of delivery, singleton or multiple birth, gestational age, stillbirth, birth weight, birth length, head circumference, infant sex, Apgar scores, and maternal and infant diagnoses/procedures, including neonatal care. The overall quality of the MBR is very high, owing to the semi-automated data extraction from the standardized regional electronic health records, Sweden's universal access to antenatal care, and the possibility to compare mothers and offspring to the Total Population Register in order to identify missing records. Through the unique personal identity numbers of mothers and live-born offspring, the MBR can be linked to other health registers. The Swedish MBR contains high-quality pregnancy-related information on more than 5 million births during five decades.

Cohort profile: a national, population-based cohort of children born after assisted conception in the UK (1992-2009): methodology and birthweight analysis

PURPOSE

To generate a large cohort of children born after assisted reproductive technology (ART) in the UK between 1992 and 2009, their naturally conceived siblings (NCS) and matched naturally conceived population (NCP) controls and linking this with health outcome data to allow exploration of the effects of ART. The effects of fresh and frozen embryo transfer on birth weight (BW) were analysed to test the validity of the cohort.

PARTICIPANTS

Children recorded on the Human Fertilisation and Embryology Authority (HFEA) register as being born after ART between 1992 and 2009, their NCS and matched NCP controls linked to Office for National Statistics birth registration dataset (HFEA-ONS cohort). This cohort was further linked to the UK Hospital Episode Statistics database to allow monitoring of the child's post-natal health outcomes up to 2015 (HFEA-ONS-HES subcohort).

FINDINGS TO DATE

The HFEA-ONS cohort consisted of 75 348 children born after non-donor ART carried out in the UK between 1 April 1992 and 31 July 2009 and successfully linked to birth registration records, 14 763 NCS and 164 823 matched NCP controls. The HFEA-ONS-HES subcohort included 63 877 ART, 11 343 NCS and 127 544 matched NCP controls further linked to health outcome data. The exemplar analysis showed that children born after fresh embryo transfers were lighter (BW difference: -131 g, 95% CI: -140 to -123) and those born after frozen embryo transfers were heavier (BW difference: 35 g, 95% CI: 19 to 52) than the NCP controls. The within-sibling analyses were directionally consistent with the population control analyses, but attenuated markedly for the fresh versus natural conception (BW difference: -54 g; 95% CI: -72 to -36) and increased markedly for the frozen versus natural conception (BW difference: 152 g; 95% CI: 113 to 190) analyses.

FUTURE PLANS

To use this cohort to explore the relationship between ART conception and short-term and long-term health outcomes in offspring.

The Danish National Register of assisted reproductive technology: content and research potentials

The Danish National Register of assisted reproductive technology (ART) was initially established in 1994. The register comprises complete information on all ART procedures in public and private clinics in Denmark from 2013 and onwards, including baseline information on the cause of infertility and a number of health-related patient characteristics. The register enables monitoring and research on infertility treatment and reproductive topics in single women or couples seeking assisted reproduction, and the register is thus a key component of the Danish health information system within human reproduction. We aimed to provide an updated description of the register including advantages and pitfalls when using the register for reproductive epidemiological research, and a description of the accessibility for researchers. The Danish ART register is a valuable tool for epidemiological research. However, the inherent strengths and limitations ought to be in perspective when designing studies and interpreting the study results. Reports with annually aggregated data on ART treatments, can be accessed on the Danish Health Data Authority web page and researchers may obtain access to individual pseudonomized data via secure servers at the Danish Health Data Authority and Statistics Denmark.

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.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

INTRODUCTION

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

OBJECTIVE

This systematic review aims to identify barriers and facilitators to health data harmonization-including data sharing and linkage-by a comparative analysis of studies from Denmark and Switzerland.

METHODS

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

RESULTS

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

CONCLUSION

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

In vitro fertilization is associated with the onset and progression of preeclampsia

OBJECTIVE

We aimed to estimate the risk of preeclampsia (PE) associated with in vitro fertilization (IVF) and potential predisposing factors responsible for the observed association.

METHODS

This retrospective cohort study included 114485 pregnant women who delivered at the Nanjing Maternity and Child Health Care Hospital between 2013 and 2018. Of the 114485 women, 4601 (4%) conceived through IVF (IVF group) and 109884 (96%) conceived spontaneously (SC group). We performed logistic regression analysis to evaluate the risk of PE following IVF compared to spontaneous conception (SC). Then, we used propensity score matching analysis to compare the clinical characteristics and pregnancy outcomes between IVF patients with and without PE.

RESULT

There were 1339 PE cases in the total study population, with a significantly higher incidence of PE in IVF relative to spontaneous pregnancies (6.1% vs. 1.0%, p < 0.01). Severe PE was more prevalent in singleton IVF-PE group than in singleton SC-PE group (40% vs. 24.1%, p = 0.025). Placenta accreta was more common in singleton preeclamptic patients with IVF than without IVF (12.5vs.2.6%, p = 0.003). Placental hypoxia was more prevalent in twin IVF pregnancies with PE than without PE (6% vs. 12.2%, p = 0.045). Moreover, the IVF-PE group showed more frequent first-trimester bleeding (31.6% vs. 10.5%, p = 0.024) compared to the control group.

CONCLUSION

IVF is associated with the onset and progression of PE. Defective placentation and placental insufficiency may predispose IVF patients to PE and may manifest as first-trimester bleeding.

Increased pregnancy complications following frozen-thawed embryo transfer during an artificial cycle

PURPOSE

This study aimed to clarify the risks of adverse pregnancy outcomes in patients and their offspring after frozen embryo transfer (FET) during an artificial cycle (AC).

METHODS

We conducted a retrospective cohort study that included all FET cycles and subsequent deliveries in a single centre between August 2013 and March 2016. Pregnancy, obstetric and neonatal outcomes were compared among patients treated during an AC or a natural cycle with luteal phase support (NC-LPS). Multivariate logistic regression was performed to evaluate the relationship between endometrial preparation schemes and pregnancy, obstetric and neonatal outcomes.

RESULTS

AC-FET was not a significant risk factor for clinical pregnancy rate, multiple birth rate or miscarriage rate after adjusting for potential confounders. However, AC-FET was a significant risk factor for ectopic pregnancy rate (adjusted odds ratio (AOR), 1.738; 95% confidence interval (CI), 1.086-2.781) and live birth rate (AOR, 0.709; 95% CI, 0.626-0.802). Regarding obstetric outcomes, AC-FET was found to be associated with an increased risk for hypertension disorder (AOR, 1.780; 95% CI, 1.262-2.510) and caesarean section (AOR, 1.507; 95% CI, 1.195-1.900). In multiples, birth weight (2550 g (2150-2900 g) in AC-FET vs. 2600 g (2350-2900 g) in NC-LPS; P = 0.023), gestational age (36.6 weeks (35.3-37.6 weeks) vs. 37.1 weeks (36.1-37.9 weeks); P < 0.001), and z-score (- 0.5 (- 1.1, - 0.0) vs. - 0.4 (- 1.0, 0.2); P = 0.009) were higher in the NC-LPS group than in the AC-FET group, although there were no differences in these variables among singletons.

CONCLUSION

Compared with NC-LPS, AC-FET seemed to have a negative effect on obstetric outcomes.

Trends over time in congenital malformations in live-born children conceived after assisted reproductive technology

INTRODUCTION

Children born after assisted reproductive technology, particularly singletons, have been shown to have an increased risk of congenital malformations compared with children born after spontaneous conception. We wished to study whether there has been a change in the past 20 years in the risk of major congenital malformations in children conceived after assisted reproductive technology compared with children spontaneously conceived.

MATERIAL AND METHODS

Population-based cohort study including 90 201 assisted reproductive technology children and 482 552 children spontaneously conceived, born in Denmark, Finland, Norway and Sweden. Both singletons and twins born after in vitro fertilization, intracytoplasmatic sperm injection and frozen embryo transfer were included. Data on children were taken from when the national Nordic assisted reproductive technology registries were established until 2007. Multiple logistic regression analyses were used to estimate the risks and adjusted odds ratios for congenital malformations in four time periods: 1988-1992, 1993-1997, 1998-2002 and 2003-2007. Only major malformations were included.

RESULTS

The absolute risk for singletons of being born with a major malformation was 3.4% among assisted reproductive technology children vs. 2.9% among children spontaneously conceived during the study period. The relative risk of being born with a major congenital malformation between all assisted reproductive technology children and children spontaneously conceived remained similar through all four time periods (p = 0.39). However, we found that over time the number of children diagnosed with a major malformation increased in both groups across all four time periods.

CONCLUSION

When comparing children conceived after assisted reproductive technology and spontaneously conceived, the relative risk of being born with a major congenital malformation did not change during the study period.

Fertility treatment and childhood type 1 diabetes mellitus: a nationwide cohort study of 565,116 live births

OBJECTIVE

To investigate the association between specific types of fertility treatment and childhood type 1 diabetes mellitus.

DESIGN

Nationwide birth cohort study.

SETTING

Not applicable.

PATIENT(S)

All pregnancies resulting in a live-born singleton child in Denmark from 1995 to 2003.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Childhood type 1 diabetes mellitus identified from redeemed prescriptions for insulin until 2013.

RESULT(S)

The study included 565,116 singleton pregnancies. A total of 14,985 children were conceived by ovulation induction or intrauterine insemination, and 8,490 children were conceived by in vitro fertilization or intracytoplasmic sperm injection. During the follow-up period, 2,011 (0.4%) children developed type 1 diabetes mellitus. The primary analyses showed no association between fertility treatment and childhood type 1 diabetes mellitus. In secondary analyses, ovulation induction or intrauterine insemination with follicle-stimulating hormone was associated with an increased risk of type 1 diabetes mellitus (hazard ratio 3.22; 95% confidence interval 1.20 to 8.64). No clear associations were seen with other types of fertility treatment or with specific treatment indications.

CONCLUSION(S)

No association between fertility treatment and childhood type 1 diabetes mellitus was found. Ovulation induction or intrauterine insemination with follicle-stimulating hormone may be associated with an increased risk of childhood type 1 diabetes mellitus. However, this finding may be due to chance or to confounding by indication and thus requires further investigation.

Validation of birth outcomes from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS): population-based analysis from the Massachusetts Outcome Study of Assisted Reproductive Technology (MOSART)

OBJECTIVE

To assess the validity of outcome data reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) compared with data from vital records and the birth defects registry in Massachusetts.

DESIGN

Longitudinal cohort.

SETTING

Not applicable.

PARTICIPANT(S)

A total of 342,035 live births and fetal deaths from Massachusetts mothers giving birth in the state from July 1, 2004, to December 31, 2008; 9,092 births and fetal deaths were from mothers who had conceived with the use of assisted reproductive technology (ART) and whose cycle data had been reported to the SART CORS.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Percentage agreement between maternal race and ethnicity, delivery outcome (live birth or fetal death), plurality (singleton, twin, or triplet+), delivery date, and singleton birth weight reported in the SART CORS versus vital records; sensitivity and specificity for birth defects among singletons as reported in the SART CORS versus the Massachusetts Birth Defects Monitoring Program (BDMP).

RESULT(S)

There was >95% agreement between the SART CORS and vital records for fields of maternal race/ethnicity, live birth/fetal death, and plurality; birth outcome date was within 1 day with 94.9% agreement and birth weight was within 100 g with 89.6% agreement. In contrast, sensitivity for report of any birth defect was 38.6%, with a range of 18.4%-50.0%, for specific birth defect categories.

CONCLUSION(S)

Although most SART CORS outcome fields are accurately reported, birth defect variables showed poor sensitivity compared with the gold standard data from the BDMP. We suggest that reporting of birth defects be discontinued.

Linking databases on perinatal health: a review of the literature and current practices in Europe

Background: International comparisons of perinatal health indicators are complicated by the heterogeneity of data sources on pregnancy, maternal and neonatal outcomes. Record linkage can extend the range of data items available and thus can improve the validity and quality of routine data. We sought to assess the extent to which data are linked routinely for perinatal health research and reporting. Methods: We conducted a systematic review of the literature by searching PubMed for perinatal health studies from 2001 to 2011 based on linkage of routine data (data collected continuously at various time intervals). We also surveyed European health monitoring professionals about use of linkage for national perinatal health surveillance. Results: 516 studies fit our inclusion criteria. Denmark, Finland, Norway and Sweden, the US and the UK contributed 76% of the publications; a further 29 countries contributed at least one publication. Most studies linked vital statistics, hospital records, medical birth registries and cohort data. Other sources were specific registers for: cancer (70), congenital anomalies (56), ART (19), census (19), health professionals (37), insurance (22) prescription (31), and level of education (18). Eighteen of 29 countries (62%) reported linking data for routine perinatal health monitoring. Conclusion: Research using linkage is concentrated in a few countries and is not widely practiced in Europe. Broader adoption of data linkage could yield substantial gains for perinatal health research and surveillance.

Are repeated assisted reproductive technology treatments and an unsuccessful outcome risk factors for unipolar depression in infertile women?

INTRODUCTION

Previous studies have shown conflicting results as to whether unsuccessful medically assisted reproduction is a risk factor for depression among women. This study therefore investigated if women with no live birth after assisted reproductive technology (ART) treatment had a higher risk of unipolar depression compared with women with a live birth after ART treatment.

MATERIAL AND METHODS

The Danish National ART-Couple (DANAC) Cohort is a national register-based cohort study that consists of women who received ART treatment from 1 January 1994 to 30 September 2009, in Denmark (n = 41 050). Information on unipolar depression was obtained from the Danish Psychiatric Central Research Register. The analyses were conducted in Cox regression analysis.

RESULTS

During the 308 494 person-years of follow up, 552 women were diagnosed with unipolar depression. A Cox proportional hazards model showed that women in ART treatment, with no live birth yet, had a lower risk of unipolar depression compared with women with a live birth. Women had the highest risk of unipolar depression 0-42 days after a live birth (adjusted hazard ratio 5.08, 95% CI 3.11-8.29) compared with women with no live birth. A lower, but still increased, risk of unipolar depression, was found in women 43 days to 1 year and >1 year after a live birth compared with women with no live birth yet.

CONCLUSIONS

Motherhood is an important trigger of unipolar depression in women conceiving after ART treatment.

Risk of hypertensive disorders in pregnancies following assisted reproductive technology: a cohort study from the CoNARTaS group

STUDY QUESTION

Is the risk of hypertensive disorders in pregnancies conceived following specific assisted reproductive technology (ART) procedures different from the risk in spontaneously conceived (SC) pregnancies?

SUMMARY ANSWER

ART pregnancies had a higher risk of hypertensive disorders, in particular following cryopreservation, with the highest risk seen in twin pregnancies following frozen-thawed cycles.

WHAT IS KNOWN ALREADY

The risk of hypertensive disorders is higher in ART pregnancies than in SC pregnancies. The increased risk may be partly explained by multiple pregnancies and underlying infertility, but a contribution from specific ART procedures has not been excluded.

STUDY DESIGN, SIZE, DURATION

Population-based cohort study, including sibling design with nationwide data from health registers in Sweden, Denmark and Norway.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All registered ART pregnancies and a sample of SC pregnancies with gestational age ≥22 weeks from 1988 to 2007 were included. ART singleton pregnancies (n = 47 088) were compared with SC singleton pregnancies (n = 268 599), matched on parity and birth year. ART twin pregnancies (n = 10 918) were compared with SC twin pregnancies (46 674). We used logistic regression to estimate adjusted odds ratios and risk differences for hypertensive disorders in pregnancies following IVF, ICSI and fresh or frozen-thawed cycles. We also compared fresh and frozen-thawed cycles within mothers who had conceived following both procedures using conditional logistic regression (sibling analysis).

MAIN RESULTS AND THE ROLE OF CHANCE

Hypertensive disorders were reported in 5.9% of ART singleton and 12.6% of ART twin pregnancies. Comparing singleton pregnancies, the risk of hypertensive disorders was higher after all ART procedures. The highest risk in singleton pregnancies was seen after frozen-thawed cycles [risk 7.0%, risk difference 1.8%, 95% confidence interval (CI) 1.2-2.8]. Comparing twin pregnancies, the risk was higher after frozen-thawed cycles (risk 19.6%, risk difference 5.1%, 95% CI 3.0-7.1), but not after fresh cycles. In siblings, the risk was higher after frozen-thawed cycles compared with fresh cycles within the same mother (odds ratio 2.63, 95% CI 1.73-3.99). There were no clear differences in risk for IVF and ICSI.

LIMITATIONS, REASONS FOR CAUTION

The number of ART siblings in the study was limited. Residual confounding cannot be excluded. In addition, we did not have information on all SC pregnancies in each woman's history, and could therefore not compare risk in ART versus SC pregnancies in the same mother.

WIDER IMPLICATIONS OF THE FINDINGS

Pregnancies following frozen-thawed cycles have a higher risk of hypertensive disorders, also when compared with fresh cycle pregnancies by the same mother. The safety aspects in frozen-thawed cycles merit further attention.

STUDY FUNDING/COMPETING INTERESTS

Funding was received from the European Society for Human Reproduction and Embryology, the University of Copenhagen, the Danish Agency for Science, Technology and Innovation, the Nordic Federation of Societies of Obstetrics and Gynecology and the Liaison Committee between the Central Norway Regional Health Authority and the Norwegian University of Science and Technology. None of the authors has any competing interests to declare.

Trends in perinatal health after assisted reproduction: a Nordic study from the CoNARTaS group

STUDY QUESTIONS

Has the perinatal outcome of children conceived after assisted reproductive technology (ART) improved over time?

SUMMARY ANSWER

The perinatal outcomes in children born after ART have improved over the last 20 years, mainly due to the reduction of multiple births.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

A Swedish study has shown a reduction in unwanted outcomes over time in children conceived after ART. Our analyses based on data from more than 92 000 ART children born in four Nordic countries confirm these findings.

STUDY DESIGN

Nordic population-based matched cohort study with ART outcome and health data from Denmark, Finland, Norway and Sweden.

PARTICIPANTS, SETTING AND METHODS

We analysed the perinatal outcome of 62 379 ART singletons and 29 758 ART twins, born from 1988 to 2007 in four Nordic countries. The ART singletons were compared with a control group of 362 215 spontaneously conceived singletons. Twins conceived after ART were compared with all spontaneously conceived twins (n = 122 763) born in the Nordic countries during the study period. The rates of several adverse perinatal outcomes were stratified into the time periods: 1988-1992; 1993-1997; 1998-2002 and 2003-2007 and presented according to multiplicity.

MAIN RESULTS AND ROLE OF CHANCE

For singletons conceived after ART, a remarkable decline in the risk of being born preterm and very preterm was observed. The proportion of ART singletons born with a low and very low birthweight also decreased. Finally, the stillbirth and infant death rates have declined among both ART singletons and twins. Throughout the 20 year period, fewer ART twins were stillborn or died during the first year of life compared with spontaneously conceived twins, presumably due to the lower proportion of monozygotic twins among the ART twins.

LIMITATIONS, REASONS FOR CAUTION

We were not able to adjust for some potential confounders such as BMI, smoking, length or cause of infertility. The Nordic ART populations have changed over time, and in recent years, both less as well as severely reproductive ill couples are being treated. This may have affected the observed trends.

WIDER IMPLICATIONS OF THE FINDINGS

It is assuring that data from four countries confirm an overall improvement over time in the perinatal outcomes of children conceived after ART. Furthermore, data show the beneficial effect of single embryo transfer, not only in regard to lowering the rate of multiples but also concerning the health of singletons.

STUDY FUNDING/COMPETING INTERESTS

The European Society for Human Reproduction and Embryology (ESHRE), the University of Copenhagen and the Danish Agency for Science, Technology and Innovation has supported the project. The CoNARTaS group has received travel and meeting funding from the Nordic Federation of Obstetrics and Gynecology (NFOG). None of the authors has any competing interests to declare.

Cancer in children and young adults born after assisted reproductive technology: a Nordic cohort study from the Committee of Nordic ART and Safety (CoNARTaS)

STUDY QUESTION

Do children and young adults born after assisted reproductive technology (ART) have an increased risk of cancer?

SUMMARY ANSWER

Children born after ART showed no overall increase in the rate of cancer when compared with children born as a result of spontaneous conception.

WHAT IS KNOWN ALREADY

Children born after ART have more adverse perinatal outcomes, i.e. preterm births, low birthweights and birth defects. Previous studies have shown divergent results regarding the risk of cancer among children born after ART.

STUDY DESIGN, SIZE, DURATION

A retrospective Nordic population-based cohort study was performed, comprising all children born after ART in Sweden, Denmark, Finland and Norway between 1982 and 2007. The mean (±standard deviation) follow-up time was 9.5 (4.8) years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Children born after ART (n = 91 796) were compared with a control group of children born after spontaneous conception. This control group was almost 4-fold the size of the ART group (n = 358 419) and matched for parity, year of birth and country. Data on perinatal outcomes and cancer were obtained from the National Medical Birth Registries, the Cancer Registries, the Patient Registries and the Cause of Death Registries. The cancer diagnoses were divided into 12 main groups. Hazard ratios (HRs) and adjusted HR were calculated. Adjustments were carried out for country, maternal age, parity, sex, gestational age and birth defects.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant increase in overall cancer rates among children born after ART when compared with children born after spontaneous conception (adjusted HR 1.08; 95% CI 0.91-1.27). Cancer, of any form, was found among 181 children born after ART (2.0/1000 children, 21.0/100 000 person-years) compared with 638 children born after spontaneous conception (1.8/1000 children, 18.8/100 000 person-years). Leukaemia was the most common type of cancer (n = 278, 0.62/1000 children) but no significantly increased incidence was found among children born after ART. An increased risk was observed for 2 of 12 cancer groups. They were central nervous system tumours (adjusted HR 1.44; 95% CI 1.01-2.05) and malignant epithelial neoplasms (adjusted HR 2.03; 95% CI 1.06-3.89); the absolute risks were 0.46/1000 and 0.15/1000 children, respectively, corresponding to an absolute increased risk of 0.14/1000 and 0.08/1000 children, respectively.

LIMITATIONS, REASONS FOR CAUTION

As this is an observational study, the main limitation is the fact that it is not possible to adjust for all potential confounders. We were not able to control for confounders such as socio-economic status and perinatal factors, such as Apgar score, which other studies have suggested affect cancer rates.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this large population-based cohort study are in agreement with most previously published studies. The main findings are reassuring for couples undergoing ART, children born after ART and clinicians working with ART.

STUDY FUNDING/COMPETING INTERESTS

No conflict of interest was reported. The study was supported by grants from The European Society for Human Reproduction and Embryology (ESHRE), Sahlgrenska University Hospital, Gothenburg, Sweden, the University of Copenhagen, Denmark, the Danish Agency of Science, Technology and Innovation and the Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).

Birth defects and congenital health risks in children conceived through assisted reproduction technology (ART): a meeting report

PURPOSE

Assisted Reproduction Treatment (ART) is here to stay. This review addresses the parental background of birth defects, before, during and after conception and focuses both on the underlying subfertility and on the question whether ART as a treatment is an additional contributing factor.

METHODS

Searches were performed in Medline and other databases. Summaries were discussed in a Delphi panel set-up by the European Society of Human Reproduction and Embryology (ESHRE).

RESULTS

Several birth defects and adult diseases arise during the earliest stages of ovarian development and oocyte differentiation: this is the case of cleft palate disorders in offspring from female rat exposed to Dioxin during fetal life or the polycystic ovary diseases in female offspring (primates) exposed to elevated androgen concentration during fetal life. Human oocytes and embryos often fail to stop the propagation of aneuploid cells but maintain their ability to repair DNA damages including those introduced by the fertilizing sperm. There is a 29 % increased risk of birth defects in the newborns spontaneously conceived by subfertile couples and the risk is further increased (34 %) when conception is achieved by treating infertlity with ART (Danish IVF Registry). Periconceptional conditions are critical for ART babies: their birth weight is in general smaller (Norvegian Registry) but a more prolonged culture time doubled the number of large babies (Finnish Registry).

CONCLUSION

The long-term developmental effects of ART on child and subsequent health as an adult remains a subject worthy of futher monitoring and investigation.

Nordic databases to evaluate medications in pregnancy

The objective of this review is to describe the possibilities to assess drugs used in pregnancy by means of the Nordic health registers. The Nordic countries comprise five countries: Denmark, Finland, Iceland, Norway and Sweden and have a total population of 25 million. All five countries have in their national health registers for many years recorded information concerning all births, cancer diagnoses, hospital contacts, causes of death and dispensed drugs. The registers can be used for studying drugs dispensed during pregnancy and though most previous studies focused on risks of congenital abnormalities, other health consequences of maternal medication can also be assessed.

Psychiatric disorders among women and men in assisted reproductive technology (ART) treatment. The Danish National ART-Couple (DANAC) cohort: protocol for a longitudinal, national register-based cohort study

INTRODUCTION

There are complex causal associations between mental disorders, fertility treatment, fertility treatment outcome and infertility per se. Eating disorders cause endocrine disturbances, anovulation and thereby infertility, and research has shown that infertility as well as unsuccessful assisted reproductive technology (ART) treatment are potential risk factors for developing a depression on a long-term basis. Despite the fact that worldwide more than 400 000 ART treatment cycles are performed every year, the causal associations between mental disorders, use of medication for mental disorders and ART treatment in both sexes have only been sparsely explored.

METHOD AND ANALYSIS

The main objective of this national register-based cohort study is to assess women's and men's mental health before, during, and after ART treatment in comparison with the mental health in an age-matched population-based cohort of couples with no history of ART treatment. Furthermore, the objective is to study the reproductive outcome of ART treatment among women who have a registered diagnosis of a mental disorder or have used medication for mental disorders prior to ART treatment compared with women in ART treatment without a mental disorder. We will establish the Danish National ART-Couple (DANAC) cohort including all women registered with ART treatment in the Danish in vitro fertilisation Register during 1994-2009 (N=42 915) and their partners. An age-matched population-based comparison cohort of women without ART treatment (n=215 290) and their partners will be established. Data will be cross-linked with data from national registers on psychiatric disorders, medical prescriptions for mental disorders, births, causes of deaths and sociodemographic data. Survival analyses and other statistical analyses will be conducted on the development of mental disorders and use of medication for mental disorders for women and men both prior to and after ART treatment.

Incidence of depression and influence of depression on the number of treatment cycles and births in a national cohort of 42,880 women treated with ART

STUDY QUESTION

Does prior depression in women treated with assisted reproduction technology (ART) influence the number of treatment cycles and ART live births?

SUMMARY ANSWER

Women with a depression diagnosis prior to ART treatment initiated statistically significantly fewer ART treatment cycles and had a lower mean number of ART live births compared with women with no history of depression.

WHAT IS KNOWN ALREADY

Previous studies have shown an increased prevalence of depressive symptoms in fertility patients than in the comparison groups.

STUDY DESIGN, SIZE, DURATION

A register-based national cohort study, including all women (n = 42,915) treated with IVF, ICSI, frozen embryo transfer and oocyte recipient cycle in Denmark from 1 January 1994 to 30 September 2009 extracted from the IVF register (ART cohort). Data on births and depression diagnoses were obtained by linking to the Danish Medical Birth Register (1994-2010) and the Danish Psychiatric Central Research Register (1969-2010).

PARTICIPANTS/MATERIALS, SETTING, METHODS

For each woman in the ART cohort, we included five age-matched women from the female background population not having received ART treatment. This comparison group was cross-linked with identical register data as the ART cohort. Women with incomplete ART information or a depression diagnosis before 18 years of age were excluded; remaining n = 42,880. The ART cohort was grouped into (i) women with a depression diagnosis and (ii) women never diagnosed with depression. In the ART group with depression, analyses were specified on women with their first depression prior to ART treatment. In total, 2.6% of the women in the ART cohort had a depression diagnosis. For the incidence rate ratio (IRR) 39,194 women from the ART cohort (3686 women were excluded due to migration) were compared with 206,005 women from the age-matched comparison group who did not receive ART treatment.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the women in the ART cohort with a depression diagnosis, 34.7% had their first depression diagnosis prior to ART treatment, 4.7% during ART treatment and 60.7% after ART treatment. The mean number of initiated ART cycles was significantly lower in the ART group of women having a depression diagnosis prior to ART treatment [2.55 (±1.78)] compared with the ART group of women without a depression diagnosis [3.22 (±2.31); P < 0.001; P < 0.001]. Women having a depression diagnosis prior to ART treatment had a lower mean number of ART live births [0.82 (±0.73)] compared with women without a depression diagnosis [1.03 (±0.81); P < 0.001]. The incidence rate of first and recurrent depression diagnoses in the ART cohort was significantly lower compared with the age-matched background population group; IRR = 0.80 (P < 0.001) and IRR = 0.77 (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Only clinical depression diagnoses treated in a psychiatric hospital setting are included. The age-matched comparison group from the background population is heterogeneous as it consists of women differing in fertility status (both mothers and childless women).

WIDER IMPLICATIONS OF THE FINDINGS

Fewer women in the ART cohort developed depression over time compared with the age-matched background population, which might reflect a healthy patient effect of the women seeking ART treatment. Women with a depression diagnosis before ART treatment receive fewer ART treatments and are less likely to achieve an ART live birth. These women might be more vulnerable and we recommend that they be offered more psychiatric attention before starting, as well as during and after ART treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Research grants are funded by the Danish Health Insurance Foundation and Merck Sharp & Dohme. The funders had no influence on the data collection, analyses or conclusions of the study. No conflict of interests to declare.

TRIAL REGISTRATION NUMBER

N/A.