Inequality in smoking and related risk factors for smoking in expectant mothers - a nationwide Danish register-based study

AIMS

Foetuses exposed to smoking during pregnancy are disadvantaged due to numerous adverse obstetric outcomes. This study aimed to examine 1) inequality in maternal smoking between subgroups of pregnant women and 2) significant risk factors of maternal smoking.

METHODS

Data were collected from Danish registries. Trends in maternal smoking within each study period, T1 (2000-2002) and T2 (2014-2016), were investigated by Poisson regression calculating prevalence proportion ratios, and trends between study periods were studied by adding an interaction term. The significance of risk factors for maternal smoking (low age, low education, living alone and having a moderate/severe mental health condition) were studied by interaction analysis on the additive scale.

RESULTS

The prevalence of maternal smoking decreased from 21% in 2000 to 7% in 2016. Decreases were found in all subgroups of maternal age, cohabitation status, educational level and mental health condition. However, large differences in smoking prevalence between subgroups were found, and inequality in maternal smoking increased from 2000 to 2016. The probability of maternal smoking increased with the addition of risk factors, and positive additive interactions were found for almost all combinations of multiple risk factors.

CONCLUSIONS

Our results provide knowledge on risk factors and increasing levels of inequality in maternal smoking which points to a need for targeted interventions in relation to maternal smoking for subgroups of pregnant women in future smoking cessation programmes and in antenatal care.

Rectal progesterone administration secures a high ongoing pregnancy rate in a personalized Hormone Replacement Therapy Frozen Embryo Transfer (HRT-FET) protocol: a prospective interventional study

STUDY QUESTION

Can supplementation with rectal administration of progesterone secure high ongoing pregnancy rates (OPRs) in patients with low serum progesterone (P4) on the day of blastocyst transfer (ET)?

SUMMARY ANSWER

Rectally administered progesterone commencing on the ET day secures high OPRs in patients with serum P4 levels below 35 nmol/l (11 ng/ml).

WHAT IS KNOWN ALREADY

Low serum P4 levels at peri-implantation in Hormone Replacement Therapy Frozen Embryo Transfer (HRT-FET) cycles impact reproductive outcomes negatively. However, studies have shown that patients with low P4 after a standard vaginal progesterone treatment can obtain live birth rates (LBRs) comparable to patients with optimal P4 levels if they receive additionalsubcutaneous progesterone, starting around the day of blastocyst transfer. In contrast, increasing vaginal progesterone supplementation in low serum P4 patients does not increase LBR. Another route of administration rarely used in ART is the rectal route, despite the fact that progesterone is well absorbed and serum P4 levels reach a maximum level after ∼2 h.

STUDY DESIGN, SIZE, DURATION

This prospective interventional study included a cohort of 488 HRT-FET cycles, in which a total of 374 patients had serum P4 levels ≥35 nmol/l (11 ng/ml) at ET, and 114 patients had serum P4 levels <35 nmol/l (11 ng/ml). The study was conducted from January 2020 to November 2022.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients underwent HRT-FET in a public Fertility Clinic, and endometrial preparation included oral oestradiol (6 mg/24 h), followed by vaginal micronized progesterone, 400 mg/12 h. Blastocyst transfer and P4 measurements were performed on the sixth day of progesterone administration. In patients with serum P4 <35 nmol/l (11 ng/ml), 'rescue' was performed by rectal administration of progesterone (400 mg/12 h) starting that same day. In pregnant patients, rectal administration continued until Week 8 of gestation, and oestradiol and vaginal progesterone treatment continued until Week 10 of gestation.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 488 HRT-FET single blastocyst transfers, the mean age of the patients at oocyte retrieval (OR) was 30.9 ± 4.6 years and the mean BMI at ET 25.1 ± 3.5 kg/m2. The mean serum P4 level after vaginal progesterone administration on the day of ET was 48.9 ± 21.0 nmol/l (15.4 ± 6.6 ng/ml), and a total of 23% (114/488) of the patients had a serum P4 level lower than 35 nmol/l (11 ng/ml). The overall, positive hCG rate, clinical pregnancy rate, OPR week 12, and total pregnancy loss rate were 66% (320/488), 54% (265/488), 45% (221/488), and 31% (99/320), respectively. There was no significant difference in either OPR week 12 or total pregnancy loss rate between patients with P4 ≥35 nmol/l (11 ng/ml) and patients with P4 <35 nmol/l, who received rescue in terms of rectally administered progesterone, 45% versus 46%, P = 0.77 and 30% versus 34%, P = 0.53, respectively. OPR did not differ whether patients had initially low P4 and rectal rescue or were above the P4 cut-off. Logistic regression analysis showed that only age at OR and blastocyst scoring correlated with OPR week 12, independently of other factors like BMI and vitrification day of blastocysts (Day 5 or 6).

LIMITATIONS, REASONS FOR CAUTION

In this study, vaginal micronized progesterone pessaries, a solid pessary with progesterone suspended in vegetable hard fat, were used vaginally as well as rectally. It is unknown whether other vaginal progesterone products, such as capsules, gel, or tablet, could be used rectally with the same rescue effect.

WIDER IMPLICATIONS OF THE FINDINGS

A substantial part of HRT-FET patients receiving vaginal progesterone treatment has lowserum P4. Adding rectally administered progesterone in these patients increases the reproductive outcome. Importantly, rectal progesterone administration is considered convenient, and progesterone pessaries are easy to administer rectally and of low cost.

STUDY FUNDING/COMPETING INTEREST(S)

Gedeon Richter Nordic supported the study with an unrestricted grant as well as study medication. B.A. has received unrestricted grant from Gedeon Richter Nordic and Merck and honoraria for lectures from Gedeon Richter, Merck, IBSA and Marckyrl Pharma. P.H. has received honoraria for lectures from Gedeon Richter, Merck, IBSA and U.S.K. has received grant from Gedeon Richter Nordic, IBSA and Merck for studies outside this work and honoraria for teaching from Merck and Thillotts Pharma AB and conference expenses covered by Merck. The other co-authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER (25)

EudraCT no.: 2019-001539-29.

Implementation of universal umbilical cord pH analysis in Denmark. A national register-based study

INTRODUCTION

Umbilical cord blood gas analysis provides information about intrapartum hypoxia and is considered an important measure of quality in maternity care. Universal measurement of umbilical cord pH (UC-pH), as part of umbilical cord blood gas analysis, has been recommended in Denmark since 2009. The recommendation is that UC-pH is measured from the umbilical cord artery (pH_UA ) and vein (pH_UV ). The aim of this study was to evaluate the national implementation of universal measurement of UC-pH.

MATERIAL AND METHODS

The study consisted of two parts. First, an evaluation of the implementation, that is, the proportion of births with measured UC-pH since the recommendation was introduced. Second, an evaluation of the cases in which UC-pH was missing. This analysis only involved births with gestational age ≥35 + 0 weeks.

RESULTS

In the period 2009 to 2018 there were 560 889 singleton, live births with registered gestational age in Denmark. The proportion of births with measured pH_UA and pH_UV increased from 12.4% in 2009 to 82.8% in 2015 and then declined to 76.9% in 2018 (p < 0.001). When comparing the group with missing pH from one or both vessels to the group with both pH_UA and pH_UV we found lower occurrence of pregnancy and births complications in the first group, body mass index ≥35 (unadjusted RR: 0.89, 95% CI: 0.85-0.93), pregnancy induced medical conditions (RR: 0.86, 95% CI: 0.84-0.89), fetal distress during birth (RR: 0.77, 95% CI: 0.76-0.79), emergency cesarean section (RR: 0.80, 95% CI: 0.78-0.83) and serious births events (RR: 0.80, 95% CI: 0.74-0.86). In contrast, the occurrence of placental insufficiency (RR: 1.07, 95% CI: 1.03-1.11), small for gestational age (RR: 1.36, 95% CI: 1.30-1.43, for <2.3th percentile), hypothermia treatment (RR: 1.60, 95% CI: 1.21-2.14) and neonatal death (RR: 1.96, 95% CI: 1.40-2.74) were higher in the group without measured pH_UA and pH_UV .

CONCLUSIONS

The use of UC-pH measurement has increased markedly in Denmark since universal measurement was recommended in 2009. Missing UC-pH from one or both vessels was associated with less complicated pregnancies and with small for gestational age, hypothermia treatment and neonatal death.

Association of birth by cesarean section with academic performance and intelligence in youth: A cohort study

INTRODUCTION

It is suggested that birth by elective cesarean section (CS) reduces the risk of birth-related infant mortality and injury. Other studies suggest an increased risk of somatic immune-related diseases among children born by CS such as asthma, type 1 diabetes, and inflammatory bowel disease. The WHO Statement on Cesarean Section Rates 2015 described an increase in CS globally. The statement concluded that the effects of CS on social and psychological outcomes remain unclear and that more research is needed to fully understand the effects of CS, including effects on cognition and intelligence in the child. Therefore, we aimed to investigate the association between delivery by CS (elective and acute) and school performance and intelligence in youth.

MATERIAL AND METHODS

This cohort study included all Danish live-born children in 1978-2000. We retrieved data regarding pregnancies, births, parents, school grades, and intelligence of the children from Danish registers and performed multiple imputations to avoid discarding data. The final cohort after exclusion comprised 1 408 230 children. Associations between CS and school graduation, grades, conscription attendance, and conscription intelligence scores were analyzed using univariate and multivariate logistic and linear regressions.

RESULTS

Adjusted odds ratio with 95% CI of graduating from lower (LSE) and upper (USE) secondary education and of attending conscription were significantly lower in the CS group: LSE graduation: 0.87 (0.84-0.89), USE graduation: 0.93 (0.92-0.94), attending conscription: 0.95 (0.93-0.98). The CS group had significantly lower grade point averages (GPA) in LSE with adjusted differences in mean total GPA of -0.090 (-0.10 to -0.007), and mean core subject GPA of -0.098 (-0.11 to -0.08), in USE with total GPA difference of -0.091 (-0.11 to -0.075) and lower mean intelligence scores of -0.36 (-0.46 to -0.27) in adjusted linear models. A sub-analysis revealed lower chances of graduating LSE and USE when born by acute rather than elective CS.

CONCLUSIONS

Chances of LSE and USE graduation and of attending conscription were significantly lower for children born by CS. However, even significant differences in mean GPAs and intelligence scores were very small, so performances when graduating school and attending conscription were comparable regardless of delivery mode.

Maternal carriage of H-Y restricting HLA class II alleles is a negative prognostic factor for women with recurrent pregnancy loss after birth of a boy

Immune system aberrations are suggested to be an important factor in the pathophysiology of unexplained secondary recurrent pregnancy loss (sRPL). The objective was to investigate if the sex ratio of the firstborn child in sRPL patients differs from the background population and whether the sex of the firstborn child has a negative impact on the pregnancy prognosis alone and/or in combination with carriage of male-specific minor histocompatibility (H-Y) restricting HLA class II alleles. From January 2016 to October 2022, 582 patients with unexplained RPL were admitted to the RPL Center of Western Denmark and continuously followed-up. HLA-DRB1 and -DQB1 typing was performed as part of the routine diagnostic work-up. In sRPL patients, a history of a firstborn boy was significantly more frequent than in the Danish background population and was associated with significantly lower odds of a successful reproductive outcome in the first pregnancy after admission compared to a firstborn girl (OR=0.41, 95% CI: 0.20-0.83, p = 0.014). The odds of a successful reproductive outcome were enhanced in patients carrying ≥ 1 H-Y-restricting HLA class II alleles with a first-born girl compared to a firstborn boy (OR=3.33, 95% CI: 1.40-7.88, p = 0.005), while no difference in successful reproductive outcome was seen in sRPL patients not carrying these alleles (OR=1.20, 95% CI: 0.33-4.43, p = 0.781). The sex ratio of children born after RPL was similar to the Danish background population. These findings confirm previous findings and suggests that a harmful immune response triggered by H-Y-antigen exposure during a previous pregnancy in preconditioned women may cause sRPL.

Psychological interventions improve quality of life despite persistent pain in endometriosis: results of a 3-armed randomized controlled trial

PURPOSE

Despite standard medical treatment endometriosis is often associated with disabling pain and poor quality of life (QoL). Studies indicate that psychological interventions (PIs) may improve pain and QoL, yet studies on the effects of PIs for women with endometriosis are sparse and limited by low-quality study designs. Therefore, this study aimed, in a rigorous three-armed design, to evaluate the effect of PIs on chronic pelvic pain (CPP) and QoL in women with endometriosis.

METHODS

This three-armed parallel, multi-center randomized controlled trial included fifty-eight endometriosis patients reporting severe CPP [≥ 5 for pain intensity measured on a 0-10-point numeric rating scale (NRS)]. Patients were randomly assigned to (1) Specific mindfulness- and acceptance-based psychological intervention (MY-ENDO), (2) Carefully matched non-specific psychological intervention (Non-specific), or (3) A wait-list control group (WL). The primary outcome was pelvic pain intensity/unpleasantness measured on NRS. Secondary outcomes included endometriosis-related quality of life, workability, pain acceptance, and endometriosis-related symptoms. Differences in outcomes between groups at post-treatment follow-up were analyzed using mixed linear models. Analyses were performed on an intention-to-treat basis.

RESULTS

Compared to WL, psychological intervention (MY-ENDO + Non-specific) did not significantly reduce pain. However, psychological intervention did significantly improve the QoL-subscales 'control and powerlessness', 'emotional well-being', and 'social support' as well as the endometriosis-related symptoms 'dyschezia' and 'constipation'. MY-ENDO was not superior to Non-specific.

CONCLUSIONS

Women with endometriosis may have significant and large effects of psychological intervention on QoL despite an ongoing experience of severe CPP.

TRIAL REGISTRATION

12 April 2016, clinicaltrials.gov (NCT02761382), retrospectively registered.

Long-Term Follow-Up on Morbidity Among Women With a History of Gestational Diabetes Mellitus: A Systematic Review

BACKGROUND

Gestational diabetes mellitus (GDM) complicates up to 10% of pregnancies and is a well-known risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease. Little is known about possible long-term risks of other diseases.

BACKGROUND

The aim was to review the literature for evidence of associations with morbidity other than T2DM and cardiovascular disease and with long-term mortality.

METHODS

A systematic review based on searches in Medline, Embase, and Cochrane Library until March 31, 2021, using a broad range of keywords. We extracted study characteristics and results on associations between GDM and disease occurrence at least 10 years postpartum, excluding studies on women with diabetes prior to pregnancy or only diabetes prior to outcome. The results are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Newcastle-Ottawa Scale was used to assess risk of bias.

RESULTS

We screened 3084 titles, 81 articles were assessed full-text, and 15 included in the review. The strongest evidence for an association was for kidney diseases, particularly in Black women. We found indication of an association with liver disease, possibly restricted to women with T2DM postpartum. The association between GDM and breast cancer had been studied extensively, but in most cases based on self-reported diagnosis and with conflicting results. Only sparse and inconsistent results were found for other cancers. No study on thyroid diseases was found, and no study reported on short-term or long-term mortality in women with a history of GDM.

CONCLUSION

Given the frequency of GDM, there is a need for better evidence on possible long-term health consequences, in particular, studies based on comprehensive records of diagnosis of GDM and long-term health outcomes.

Is paternal age associated with transfer day, developmental stage, morphology, and initial hCG-rise of the competent blastocyst leading to live birth? A multicenter cohort study

In this study we investigated whether age of men undergoing assisted reproductive technology (ART) treatment was associated with day of transfer, stage, morphology, and initial hCG-rise of the competent blastocyst leading to a live birth? The design was a multicenter historical cohort study based on exposure (age) and outcome data (blastocyst stage and morphology and initial hCG-rise) from men whose partner underwent single blastocyst transfer resulting in singleton pregnancy/birth. The ART treatments were carried out at sixteen private and university-based public fertility clinics. We included 7246 men and women, who between 2014 and 2018 underwent controlled ovarian stimulation (COS) or Frozen-thawed Embryo Transfer (FET) with a single blastocyst transfer resulting in singleton pregnancy were identified. 4842 men with a partner giving birth were included, by linking data to the Danish Medical Birth Registry. We showed that the adjusted association between paternal age and transfer day in COS treatments was OR 1.06, 95% CI (1.00;1.13). Meaning that for every increase of one year, men had a 6% increased probability that the competent blastocyst was transferred on day 6 compared to day 5. Further we showed that the mean difference in hCG values when comparing paternal age group 30–34, 35–39 and 40–45 with the age group 25–29 in those receiving COS treatment, all showed significantly lower adjusted values for older men. In conclusion we hypothesize that the later transfer (day 6) in female partners of older men may be due to longer time spent by the oocyte to repair fragmented DNA of the sperm cells, which should be a focus of future research in men.

Plasma level of mannose-binding lectin is associated with the risk of recurrent pregnancy loss but not pregnancy outcome after the diagnosis

STUDY QUESTION

Are low or high plasma mannose-binding lectin (p-MBL) levels associated with recurrent pregnancy loss (RPL) and the reproductive and perinatal outcomes before and after RPL?

SUMMARY ANSWER

The prevalence of low p-MBL levels was significantly higher in RPL patients, while high levels were significantly less prevalent. No association was found between p-MBL level and reproductive and perinatal outcomes before and after RPL.

WHAT IS KNOWN ALREADY

Mannose-binding lectin (MBL) is an important component in the innate immune system. Low p-MBL levels have been associated with RPL, while the correlation with high levels has been poorly studied. Adverse perinatal outcomes are generally more frequent among RPL patients, but reports concerning the association between maternal p-MBL levels and perinatal outcomes, including birth weight (BW) and gestational age (GA), are conflicting.

STUDY DESIGN, SIZE, DURATION

This study was a combined cross-sectional and cohort study of 267 RPL patients admitted to the RPL Center of Western Denmark between January 2016 and March 2020. RPL patients were followed until birth of a liveborn child or until end of follow-up, March 2021. A sample of 185 healthy female blood donors of reproductive age was used as a MBL reference group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All RPL patients had ≥3 consecutive pregnancy losses, a regular menstrual cycle and no known significant chromosomal or uterine malformations. At the first consultation, routine blood samples including p-MBL measurement and detailed obstetrical and perinatal information were collected. p-MBL levels in RPL patients were compared to the MBL reference group. A logistic regression analysis adjusted for relevant confounders assessed the association between low p-MBL levels and an unsuccessful reproductive outcome in RPL patients in first pregnancy after admission. Perinatal outcomes before and after RPL were compared between RPL subgroups according to low (≤500 µg/l), intermediate (501–3000 µg/l) and high (>3000 µg/l) p-MBL levels.

MAIN RESULTS AND THE ROLE OF CHANCE

Significantly more RPL patients had low p-MBL levels (prevalence proportion ratio (PPR): 1.79, 95% CI: 1.34–2.38) and fewer had high p-MBL levels (PPR: 0.56, 95% CI: 0.40–0.79) compared to the reference group, while the prevalence of intermediate p-MBL level was not different between the groups (PPR: 0.86, 95% CI: 0.69–1.08). In the prospective study, low p-MBL level was not a significant risk factor for a pregnancy loss in the first pregnancy after admission after adjustment for age, BMI and smoking. Neither before nor after the RPL diagnosis were maternal p-MBL levels significantly associated with BW or GA.

LIMITATIONS, REASONS FOR CAUTION

Only 161 (60.3%) patients had given birth after RPL during the follow-up period, which limited the possibility to detect clear associations between p-MBL levels and perinatal outcomes after RPL.

WIDER IMPLICATIONS OF THE FINDINGS

In agreement with several previous studies, low p-MBL levels are strongly associated with RPL, while this study for the first time documents that high levels may play a protective role, which suggests a causal relationship. We suggest that larger prospective studies evaluate the association between p-MBL levels and RPL prognosis.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. We acknowledge the Department of Obstetrics and Gynaecology at Aalborg University Hospital for financial support. U.S.K. has reported personal fees from Merck, consulting fees from IBSA Nordic, and a grant from Gedeon Richter, Merck and IBSA Nordic outside of the submitted work.

TRIAL REGISTRATION NUMBER

ID from clinicaltrials.gov is NCT04017754.

Patients' choices and opinions on chorionic villous sampling and non-invasive alternatives for prenatal testing following preimplantation genetic testing for hereditary disorders: A cross-sectional questionnaire study

OBJECTIVE

The aim of this study was to investigate choices of and reasoning behind chorionic villous sampling and opinions on non-invasive prenatal testing among women and men achieving pregnancy following preimplantation genetic testing (PGT) for hereditary disorders.

METHODS

A questionnaire was electronically submitted to patients who had achieved a clinical pregnancy following PGT at the Center for Preimplantation Genetic Testing, Aalborg University Hospital, Denmark, between 2017 and 2020.

RESULTS

Chorionic villous sampling was declined by approximately half of the patients. The primary reason for declining was the perceived risk of miscarriage due to the procedure. Nine out of 10 patients responded that they would have opted for a non-invasive prenatal test if it had been offered. Some patients were not aware that the nuchal translucency scan offered to all pregnant women in the early second trimester only rarely provides information on the hereditary disorder for which PGT was performed.

CONCLUSION

Improved counseling on the array of prenatal tests and screenings available might be required to assist patients in making better informed decisions regarding prenatal testing. Non-invasive prenatal testing is welcomed by the patients and will likely increase the number of patients opting for confirmatory prenatal testing following PGT for hereditary disorders.

Developmental stage and morphology of the competent blastocyst are associated with sex of the child but not with other obstetric outcomes: a multicenter cohort study

STUDY QUESTION

Are transfer day, developmental stage and morphology of the competent blastocyst in pregnancies leading to live birth associated with preterm birth, birthweight, length at birth and sex of the child?

SUMMARY ANSWER

A high score in blastocyst developmental stage and in trophectoderm (TE) showed a significant association with the sex of the child, while no other associations with obstetric outcomes were observed.

WHAT IS KNOWN ALREADY

The association between blastocyst assessment scores and obstetric outcomes have been reported in small single-center studies and the results are conflicting.

STUDY DESIGN, SIZE, DURATION

Multicenter historical cohort study based on exposure data (transfer day (blastocyst developmental stage reached by Day 5 or Day 6)) blastocyst developmental stage (1-6) and morphology (TE and inner cell mass (ICM): A, B, C)) and outcome data (preterm birth, birthweight, length at birth, and sex of the child) from women undergoing single blastocyst transfer resulting in a singleton pregnancy and live birth.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data from 16 private and university-based facilities for clinical services and research were used. A total of 7246 women, who in 2014-2018 underwent fresh-embryo transfer with a single blastocyst or frozen-thawed embryo transfer (FET) with a single blastocyst resulting in a singleton pregnancy were identified. Linking to the Danish Medical Birth Registry resulted in a total of 4842 women with a live birth being included. Cycles with pre-implantation genetic testing and donated gametes were excluded. The analyses were adjusted for female age (n = 4842), female BMI (n = 4302), female smoking (n = 4290), parity (n = 4365), infertility diagnosis (n = 4765), type of treatment (n = 4842) and center (n = 4842); some analyses additionally included gestational age (n = 4368) and sex of the child (n = 4833).

MAIN RESULTS AND THE ROLE OF CHANCE

No statistically significant associations between blastocyst assessment scores (transfer day, developmental stage, TE, ICM) and preterm birth (8.3%) or birthweight (mean 3461.7 g) were found. The adjusted association between blastocysts with a TE score of C and a TE score of A and length at birth (mean 51.6 cm) were statistically significant (adjusted mean difference 0.4 cm (95% CI: 0.02; 0.77)). Blastocysts transferred with developmental stage score 5 compared to blastocysts transferred with score 3 had a 34% increased probability of being a boy (odds ratio (OR) 1.34 (95% CI: 1.09; 1.64). Further, TE score B blastocysts compared to TE score A blastocysts had a 31% reduced probability of being a boy (OR 0.69 (95% CI: 0.60; 0.80)).

LIMITATIONS, REASONS FOR CAUTION

It is possible that some residual confounding remains.

WIDER IMPLICATIONS OF THE FINDINGS

Blastocyst selection during ART does not appear to introduce any negative effects on obstetric outcome. Therefore, clinicians and patients can be reassured that the assessment scores of the selected blastocyst will not in themselves pose a risk of preterm birth or affect birthweight and the length at birth.

STUDY FUNDING/COMPETING INTEREST(S)

Unrestricted grant from Gedeon Richter Nordics AB, Sweden. None of the authors have any competing interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Health-related quality of life in women with endometriosis: psychometric validation of the Endometriosis Health Profile 30 questionnaire using confirmatory factor analysis

STUDY QUESTION

Which of the competing models of the Endometriosis Health Profile 30 Questionnaire (EHP-30) factor structure is best supported by confirmatory factor analysis (CFA)?

SUMMARY ANSWER

Findings support a five-factor first-order model of the EHP-30, thereby lending support to the model originally suggested by the questionnaire developers.

WHAT IS KNOWN ALREADY

Endometriosis has a negative impact on quality of life, and measures specifically developed to address this impact, such as the EHP-30, are vital in research and disease management. Previous studies have found different models of the EHP-30 factor structure, and generated uncertainty regarding how to use the questionnaire. CFA can be applied to compare competing factor models and determine the underlying structure of a questionnaire.

STUDY DESIGN SIZE DURATION

This cross-sectional multicenter study included 304 women with endometriosis recruited from three different public health service endometriosis clinics (referral centers for treatment of severe endometriosis) and the Danish Endometriosis Patients Association from 2014 to 2015.

PARTICIPANTS/MATERIALS SETTING METHODS

Diagnosis of endometriosis was confirmed in medical records for 84.2% and by histology for 66.8% of participants. Questionnaires (the licensed Danish version of the EHP-30) were sent by post two times with a 6- to 12-week interval. CFA was used to examine construct validity and Bland-Altman plots to examine test-retest reliability and the convergent validity with the Short Form 36 version 2.

MAIN RESULTS AND THE ROLE OF CHANCE

Response rate was high (87.6%). CFA supported the original first-order five-factor structure of the EHP-30, and thereby, the use of five separate scale-scores in clinical and research practice. Visual inspection of Bland-Altman plots suggested excellent test-retest reliability of the EHP-30 and supported the use of a disease specific quality of life instrument for women with endometriosis.

LIMITATIONS REASONS FOR CAUTION

Diagnosis could not be confirmed through histology data in 33.2% of participants. However, subgroup analyses based on women with confirmed histology only, yielded similar results. Data related to menstrual cycle stage and the use of hormonal and pain medication during questionnaire completion were not collected. A larger study, including data from different countries on different continents, would be better designed to exclude potential population bias.

WIDER IMPLICATIONS OF THE FINDINGS

EHP-30, with its original five-factor structure, appears to be a valid, stable, and specific quality of life measure for women with endometriosis. It seems easy to understand, quick to administer, and importantly, scoring might be unaffected by cyclical/menstrual pain symptoms related to endometriosis. The finding of a five-factor model from different studies across several countries supports the crosscultural validity of the EHP-30.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Danish Endometriosis Association, which is a nongovernmental organization run by women with endometriosis and by a scholarship from the Health Research Fund of Central Denmark Region. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

The Danish Data Protection Agency (J.nr: 2013-41-2264).

GnRH agonist supplementation in hormone replacement therapy-frozen embryo transfer cycles: a randomized controlled trial

RESEARCH QUESTION

Will two boluses of gonadotrophin-releasing hormone agonist (GnRHa) during hormone replacement therapy-frozen embryo transfer (HRT-FET) cycles reduce the total pregnancy loss rate?

DESIGN

Randomized controlled trial including a total of 287 HRT-FET cycles performed between 2013 and 2019. After randomization participants allocated to the GnRHa group (n = 144) underwent a standard HRT protocol, supplemented with a total of two boluses of triptorelin 0.1 mg; one bolus 2 days before starting vaginal progesterone and one bolus on the 7th day of progesterone. The control group (n = 143) underwent a standard HRT-FET protocol only.

RESULTS

The intention-to-treat analysis showed no significant difference in total pregnancy loss between the GnRHa group and the control group (21% versus 33%; relative risk [RR] 0.63, 95% confidence interval [CI] 0.35-1.11), nor was the biochemical pregnancy loss per positive human chorionic gonadotrophin (HCG) significantly lower in the GnRHa group (12%, 8/67) compared with the control group (25%, 18/72) (RR 0.48, 95% CI 0.22-1.02). Participants with a live birth had a significantly higher mean progesterone concentration compared with participants without a live birth (25.0 ± 12.2 versus 23.8 ± 8.9 nmol/l; P = 0.001). Furthermore, a trend for a higher live birth rate (LBR) correlated with the highest oestradiol quartile concentration (oestradiol >0.957 nmol/l).

CONCLUSIONS

Although a difference of 14% in biochemical loss and 12% in total pregnancy loss in favour of GnRHa supplementation was seen this did not reach statistical difference. Luteal progesterone and oestradiol concentrations correlate with LBR in the HRT-FET cycle, emphasizing the importance of luteal serum progesterone and oestradiol monitoring.

Fertility treatment with clomiphene citrate and childhood epilepsy: a nationwide cohort study

STUDY QUESTION

Is fertility treatment with clomiphene citrate associated with an increased risk of childhood epilepsy, including specific subtypes of epilepsy?

SUMMARY ANSWER

Fertility treatment with clomiphene citrate may be associated with a small increased risk of idiopathic generalized epilepsy and focal epilepsy in childhood.

WHAT IS KNOWN ALREADY

Clomiphene citrate is among the most commonly prescribed drugs for fertility treatment. However, concerns have been raised as to whether the treatment may harm the developing fetus.

STUDY DESIGN, SIZE, DURATION

This nationwide cohort study included all pregnancies in Denmark from 1 July 1995 resulting in a live-born singleton child before 31 December 2013. The children were followed until 31 December 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Children conceived after fertility treatment with clomiphene citrate were identified from the Danish National Prescription Registry. The primary outcomes were childhood epilepsy, idiopathic generalized epilepsy, and focal epilepsy identified from the Danish National Patient Register and from antiepileptic drug prescriptions in the Danish National Prescription Registry. All analyses were conducted using Cox proportional hazards regression.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1 081 291 pregnancies were included; 12 644 children (1.2%) developed epilepsy. Fertility treatment with clomiphene citrate was associated with a small increased risk of childhood epilepsy (hazard ratio [HR]: 1.10; 95% CI: 1.00-1.22), idiopathic generalized epilepsy (HR: 1.41; 95% CI: 1.16-1.72), and focal epilepsy (HR: 1.26; 95% CI: 1.04-1.53).

LIMITATIONS, REASONS FOR CAUTION

The increased risk of idiopathic generalized epilepsy may be due to confounding from time stable parental characteristics related to treatment with clomiphene citrate, since the association was strongest with the lowest administered dosage of clomiphene citrate prior to conception, and the association disappeared in a sibling analysis.

WIDER IMPLICATIONS OF THE FINDINGS

The increased risk of focal epilepsy may be related to the hormonal treatment, since the association tended to increase with increasing cumulative dosage of clomiphene citrate prior to conception, and the association persisted in a sibling analysis. This finding may be of clinical importance, since alternative hormones are available for fertility treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Financial support from Aarhus University and the Aase and Ejnar Danielsen Foundation. U.S.K. received personal teaching fees from Merck, outside the submitted work.

TRIAL REGISTRATION NUMBER

N/A.

Early ovarian ageing: is a low number of oocytes harvested in young women associated with an earlier and increased risk of age-related diseases?

STUDY QUESTION

Do young women with early ovarian ageing (EOA), defined as unexplained, and repeatedly few oocytes harvested in ART have an increased risk of age-related events?

SUMMARY ANSWER

At follow-up, women with idiopathic EOA had an increased risk of age-related events compared to women with normal ovarian ageing (NOA).

WHAT IS KNOWN ALREADY

Early and premature menopause is associated with an increased risk of cardiovascular diseases (CVDs), osteoporosis and death. In young women, repeated harvest of few oocytes in well-stimulated ART cycles is a likely predictor of advanced menopausal age and may thus serve as an early marker of accelerated general ageing.

STUDY DESIGN, SIZE, DURATION

A register-based national, historical cohort study. Young women (≤37 years) having their first ART treatment in a public or private fertility clinic during the period 1995-2014 were divided into two groups depending on ovarian reserve status: EOA (n = 1222) and NOA (n = 16 385). Several national registers were applied to assess morbidity and mortality.

PARTICIPANTS/MATERIALS, SETTING, METHODS

EOA was defined as ≤5 oocytes harvested in a minimum of two FSH-stimulated cycles and NOA as ≥8 oocytes in at least one cycle. Cases with known causes influencing the ovarian reserve (endometriosis, ovarian surgery, polycystic ovary syndrome, chemotherapy etc.) were excluded. To investigate for early signs of ageing, primary outcome was an overall risk of ageing-related events, defined as a diagnosis of either CVD, osteoporosis, type 2 diabetes, cancer, cataract, Alzheimer's or Parkinson's disease, by death of any-cause as well as a Charlson comorbidity index score of ≥1 or by registration of early retirement benefit. Cox regression models were used to assess the risk of these events. Exposure status was defined 1 year after the first ART cycle to assure reliable classification, and time-to-event was measured from that time point.

MAIN RESULTS AND THE ROLE OF CHANCE

Median follow-up time from baseline to first event was 4.9 years (10/90 percentile 0.7/11.8) and 6.4 years (1.1/13.3) in the EOA and NOA group, respectively. Women with EOA had an increased risk of ageing-related events when compared to women with a normal oocyte yield (adjusted hazard ratio 1.24, 95% CI 1.08 to 1.43). Stratifying on categories, the EOA group had a significantly increased risk for CVD (1.44, 1.19 to 1.75) and osteoporosis (2.45, 1.59 to 3.90). Charlson comorbidity index (1.15, 0.93 to 1.41) and early retirement benefit (1.21, 0.80 to 1.83) was also increased, although not reaching statistical significance.

LIMITATIONS, REASONS FOR CAUTION

Cycles never reaching oocyte aspiration were left out of account in the inclusion process and we may therefore have missed women with the most severe forms of EOA. We had no information on the total doses of gonadotrophin administered in each cycle.

WIDER IMPLICATIONS OF THE FINDINGS

These findings indicate that oocyte yield may serve as marker of later accelerated ageing when, unexpectedly, repeatedly few oocytes are harvested in young women. Counselling on life-style factors as a prophylactic effort against cardiovascular and other age-related diseases may be essential for this group of women.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received for this study. All authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Effect of early discharge after planned cesarean section on recovery and parental sense of security. A randomized clinical trial

INTRODUCTION

In some European countries, discharge the day after planned cesarean section has become an accepted procedure. However, little is known about the patients' perception of early discharge. The aim of this study was to compare early discharge with standard care in relation to parental sense of security. Further, we evaluated postoperative pain, mobilization, and readmission.

MATERIAL AND METHODS

We performed a randomized clinical trial including parous, singleton pregnant women with a planned cesarean section at term. The women were allocated to either discharge within 28 hours (intervention group) or after 48 hours (standard care group) following the cesarean section. Women discharged within 28 hours after cesarean section were offered a home visit by a midwife the following day. The primary outcome was the postnatal sense of security, which was reported by the woman and her partner in the "Parents' Postnatal Sense of Security" questionnaire 1 week postpartum. Secondary outcomes were pain score, use of analgesics, mobilization, readmission, and contacts with the healthcare system in the postoperative period.

RESULTS

We included 143 women, of whom 72 were allocated to the intervention group and 71 were allocated to the standard care group. There were no differences in baseline characteristics. The two groups did not differ concerning the postnatal sense of security for the women (P = .98) or the postnatal sense of security for the partners (P = .38). We found no difference in pain scores, step count, use of analgesics, or number of contacts with the health-care system between the groups.

CONCLUSIONS

Parental postnatal sense of security is not compromised by discharge within 28 hours followed by a home visit compared with discharge after 48 hours after planned cesarean section among parous women.

Length of hospital stay after cesarean section in Denmark from 2004 to 2016: A national register-based study

INTRODUCTION

Length of hospital stay after birth has decreased during the last decades, but nationwide data on length of hospital stay after cesarean section are lacking. Elements of Enhanced Recovery Programs were reported to reduce the length of hospital stay. The aim of this nationwide study was to describe the length of hospital stay after cesarean section in Denmark from 2004 to 2016 taking into account birth- and health-related factors as well as demographic changes and, further, to assess potential differences between the five Danish regions.

MATERIAL AND METHODS

Length of hospital stay was assessed in 164 209 deliveries by cesarean section in Denmark from 2004 to 2016. Data were obtained from the Danish National Patient Register. All deliveries by cesarean section at gestational age <22 weeks were excluded. Median length of hospital stay was reported based on crude and adjusted analyses.

RESULTS

The median length of hospital stay was significantly reduced by 39 hours (95% confidence interval [CI] 37.9-40.1), from 97 hours (4.0 days) in 2004 to 58 hours (2.4 days) in 2016. Reductions were observed among both planned and emergency cesarean sections. When birth- and health-related factors as well as demographic changes were accounted for, median length of hospital stay was reduced by 30 hours (95% CI 29.3-30.8) in the period. The decrease in length of hospital stay from 2004 to 2016 varied between the five Danish regions, with adjusted reductions between 19 and 46 hours.

CONCLUSIONS

A nationwide decrease in length of hospital stay after cesarean section was observed from 2004 to 2016 across all five regions but with significant regional variations. Further studies on the optimal length of hospital stay are needed, especially with regard to implementation of enhanced recovery programs.

Female cigarette smoking and successful fertility treatment: A Danish cohort study

INTRODUCTION

Despite smoking being a well-established risk factor for adverse pregnancy and neonatal outcomes, a substantial proportion of women of reproductive age smoke. Previously, meta-analyses have indicated a significantly negative impact of female smoking on outcomes of assisted reproduction, yet most of the included studies have several, essential methodological limitations. We aimed to investigate whether female cigarette smoking may affect the chance of achieving a clinical pregnancy and live birth among women and couples receiving medically assisted reproduction treatment.

MATERIAL AND METHODS

A cohort study with longitudinally and repeatedly collected exposure information from 1 January 2010 to 31 August 2015, including data on 1708 women and potential partners initiating either intrauterine insemination, in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) or frozen embryo transfer treatment cycles at the public Fertility Clinic, Aarhus University Hospital, Denmark. Smoking was assessed from self-reported questionnaires completed before treatment. Outcomes were a clinical pregnancy and a live birth. Information on these was obtained from the Danish national health registries, allowing complete follow-up. To evaluate associations between female occasional/daily cigarette smoking and successful medically assisted reproduction treatments, a modified Poisson regression with robust standard errors was used.

RESULTS

Female occasional/daily cigarette smoking was not associated with the chance of achieving a clinical pregnancy or a live birth in all intrauterine insemination or IVF/ICSI treatment cycles. When compared with nonsmokers, the adjusted relative risk for obtaining a live birth for those reporting smoking was 1.22 (0.70-2.12) among women initiating 1456 intrauterine insemination treatment cycles. Among women initiating 2788 IVF/ICSI treatment cycles, those reporting occasional/daily smoking had a relative risk for obtaining a live birth of 1.15 (0.82-1.60) when compared with nonsmokers.

CONCLUSIONS

Occasionally/daily cigarette smoking women had similar chance of achieving a clinical pregnancy or a live birth as the nonsmokers when receiving medically assisted reproduction treatments. However, tobacco use before and during pregnancy remains a major cause of reduced fertility as well as maternal, fetal, and infant morbidity and mortality, and should strongly be discouraged.

Uterine fibroids increase time to pregnancy: a cohort study

Objectives: The primary purpose of the study was to investigate a possible association between uterine fibroids and time to pregnancy (TTP), and, secondly, to explore the effect of myomectomy on TTP.Methods: This historical cohort study used data from the Danish National Birth Cohort and the Danish National Patient Registry. The study population consisted of 86,323 women with 92,696 pregnancies. The main outcome was TTP; groups were compared using a binary outcome: TTP >12 months or TTP ≤12 months.Results: Women who had a fibroid diagnosis code before attempting to conceive (n = 92) had an increased risk of TTP >12 months compared with women without a fibroid diagnosis code (n = 87,358) (adjusted odds ratio [OR] 1.67; 95% confidence interval [CI] 1.05, 6.68). Women who had a fibroid diagnosis code after pregnancy (n = 963) also had an increased risk of TTP >12 months compared with women without a fibroid diagnosis code (adjusted OR 1.24; 95% CI 1.04, 1.47).Conclusion: We found an association between having a uterine fibroid diagnosis code and TTP >12 months. We were not able to make a valid assessment of the effect of myomectomy on TTP.

Children Born by Women With Rheumatoid Arthritis and Increased Susceptibility for Chronic Diseases: A Nationwide Cohort Study

OBJECTIVE

Fetal exposure to maternal rheumatoid arthritis (RA) might impact the long-term risk of disease in the offspring. We examined a possible association between maternal RA and 15 selected groups of chronic diseases in the offspring.

METHODS

This nationwide cohort study was based on the Danish health registries and included data on all children born alive in Denmark between January 1, 1989 and December 31, 2013. The cohort comprised 2,106 children born by women with RA (exposed), and 1,378,539 children born by women without RA (unexposed). Cox proportional hazards regression models were used, taking a large range of confounders into consideration, and the hazard ratios (HRs) of child and adolescent diseases were calculated.

RESULTS

In children exposed to maternal RA in utero, the HR of thyroid diseases was 2.19 (95% confidence interval [95% CI] 1.14-4.21), epilepsy 1.61 (95% CI 1.16-2.25), and RA 2.89 (95% CI 2.06-4.05). The HRs for anxiety and personality disorders and chronic lung disease including asthma were in the range of 1.15-1.16, but these were not statistically significant associations.

CONCLUSION

Our results suggest that in utero exposure to maternal RA is associated with an increased risk of thyroid disease and epilepsy in childhood and adolescence, and in particular an increased risk of RA, compared to children born to mothers without RA. These important findings should encourage pediatricians and general practitioners to have an increased awareness of certain chronic diseases in children exposed to RA in utero.

Low-to-moderate alcohol consumption and success in fertility treatment: a Danish cohort study

STUDY QUESTION

Does female weekly alcohol intake and binge drinking impact the chance of a successful fertility treatment?

SUMMARY ANSWER

Low-to-moderate weekly alcohol drinking and binge drinking were not associated with the chance of achieving a clinical pregnancy or a live birth among women and couples undergoing medically assisted reproduction (MAR) treatments.

WHAT IS KNOWN ALREADY

Alcohol consumption is common among women of reproductive age, even though health authorities advise women trying to conceive to abstain from drinking. A growing number of couples struggle with infertility, but it is unknown whether low-to-moderate levels of alcohol consumption and alcohol binge drinking impair success in fertility treatment.

STUDY DESIGN, SIZE, DURATION

Cohort study with prospectively collected exposure information including 1708 women and potential partners undergoing fertility treatment at the public fertility clinic, Aarhus University Hospital, 1 January 2010 to 31 August 2015. In total, data on 1511 intrauterine insemination (IUI) cycles, 2870 in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles and 1355 frozen embryo transfer cycles.

PARTTICIPANTS/MATERIALS, SETTING, METHODS

Exposure to weekly average alcohol intake was assessed from questionnaires completed by participants before the start of treatment. Outcome measures are the achievement of a clinical pregnancy and live birth in consecutive treatment cycles in the Danish national health registries, enabling complete follow-up. A modified Poisson regression with robust standard errors was used to evaluate associations between a weekly average alcohol intake and MAR outcomes, adjusting for female age, body mass index, cigarette smoking, coffee consumption, chronic diseases, level of education, and cycle number. When evaluating the association between binge drinking in the month prior to baseline and MAR outcomes the analyses were further adjusted for average weekly alcohol consumption.

MAIN RESULTS AND THE ROLE OF CHANCE

Low-to-moderate average weekly alcohol intake was not statistically significantly associated with the chance of achieving a clinical pregnancy or a live birth following IUI or IVF/ICSI treatment cycles. Compared to women abstaining from alcohol, the adjusted relative risks for achieving a live birth among those reporting 1–2, 3–7, and &gt;7 drinks per week were 1.00 (95% CI 0.66; 1.53), 1.20 (0.76; 1.91), and 1.48 (0.56; 3.93), respectively, among women initiating IUI treatments. Among those initiating IVF/ICSI treatments, the chance for achieving a live birth among those reporting 1–2, 3–7, and &gt;7 drinks per week were 1.00 (0.83; 1.21), 0.95 (0.75; 1.20), and 0.89 (0.53; 1.51), respectively. The chance of achieving a live birth in the first IUI or IVF/ICSI treatment cycle was unrelated to the number of binge drinking episodes in the month preceding baseline.

LIMITATIONS, REASONS FOR CAUTION

The risk of non-differential exposure misclassification, confounding, or chance cannot be ruled out. In addition, due to the low number of women reporting an intake of &gt;7 drinks/week, the potential effect of high alcohol consumption should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

Although it remains unsettled if and how alcohol affects female reproduction, our results indicate that is not necessary to abstain from alcohol when striving for a successful outcome following fertility treatment.

STUDY FUNDING/COMPETING INTEREST(S)

J.L. is supported by a fully financed Ph.D. scholarship from Aarhus University and has received funds from the A.P. Møller foundation. The funding sources had no involvement in the conduct of the article. Dr Kesmodel reports personal fees from MSD and Ferring Pharmaceuticals outside the submitted work. All other authors have no conflicts of interest to declare and all have completed the ICMJE disclosure form.

TRIAL REGISTRATION NUMBER

Not relevant.

Conservative treatment of rectosigmoid endometriosis: A prospective study

INTRODUCTION

Deep infiltrating endometriosis is a common cause of pelvic pain. However, some patients have limited problems that may be controlled by medical treatment, so avoiding the potentially severe complications of major surgery. This approach requires detailed knowledge on quality of life and clinical symptoms over time. The aim of the study was to monitor these parameters in patients with rectosigmoid endometriosis treated with oral contraceptives, oral gestagens, and/or the levonorgestrel-releasing intrauterine device. Moreover, nodule size measurements performed with transvaginal sonography were correlated to severity of symptoms.

MATERIAL AND METHODS

Conservatively treated patients on oral contraceptives, oral gestagens, or the levonorgestrel-releasing intrauterine device underwent transvaginal sonography and answered a self-administered questionnaire regarding clinical symptoms and quality of life (Short Form 36 and Endometriosis Health Profile 30) at baseline, and 6 and 12 months later.

RESULTS

Eighty women completed the follow up. Scores of quality of life were comparable to normative data for Danish women of similar age and did not change with time. No association between change in size of the rectosigmoid nodule and change in symptoms was seen.

CONCLUSIONS

This study supports that simple treatment with oral contraceptives, oral gestagens, or the levonorgestrel-releasing intrauterine device represents a viable therapeutic approach to rectosigmoid Deep infiltrating endometriosis, provided that proper selection of patients in need of surgery exists.

Risk of stillbirth in low-risk singleton term pregnancies following fertility treatment: a national cohort study

OBJECTIVE

To assess the risk of stillbirth in low-risk in vitro fertilisation (IVF) pregnancies.

DESIGN

Register-based national cohort study.

SETTING

Denmark 2003-2013.

POPULATION

Cohort of 425 732 singleton pregnancies including 10 235 conceived following IVF/intracytoplasmic sperm injection (ICSI), 4521 conceived following intrauterine insemination (IUI), and 410 976 spontaneously conceived.

METHODS

Information on pregnancy, obstetrical risk factors, stillbirth, and fertility treatment was obtained from the Danish national health registers for all pregnancies after gestational week 21⁺⁶ . We estimated the overall and gestational age-specific risk of stillbirth in low-risk term pregnancies following IVF, ICSI, and IUI. Further, we estimated the association between stillbirth and IVF and ICSI respectively as well as fresh or frozen-thawed embryo transfer.

MAIN OUTCOME MEASURES

Risk of stillbirth.

RESULTS

The number of stillbirths in spontaneously conceived and IVF/ICSI low-risk term pregnancies was 525 (0.1%) and 35 (0.3%), respectively. In multivariate analysis, the risk of stillbirth in pregnancies following IVF/ICSI was increased (odds ratio 2.1, 95% CI 1.4-3.1). The risk of stillbirth was correspondingly increased in time-to-event analyses taking risk time for each fetus into account from gestational week 37 and onwards (hazard ratio 2.4, 95% CI 1.6-3.6). In sub-analyses, the risk of stillbirth was increased for pregnancies following ICSI (odds ratio 2.2, 95% CI 1.2-3.1), but not IVF (odds ratio 1.7, 95% CI 0.9-3.1).

CONCLUSION

We found a systematically increased risk of stillbirth in low-risk term pregnancies following IVF/ICSI. Whether the risk was related to the treatment or to underlying subfertility is uncertain. The results may indicate a need for obstetrical surveillance for these pregnancies when reaching term.

TWEETABLE ABSTRACT

Increased risk of stillbirth in low-risk term pregnancies following fresh cycle IVF/ICSI.

Information bias in epidemiological studies with a special focus on obstetrics and gynecology

Information bias occurs when any information used in a study is either measured or recorded inaccurately. This paper describes some of the most common types of information bias, using examples from obstetrics and gynecology, and describes how information bias may affect results of observational studies. Non-differential misclassification occurs when the degree of misclassification of exposure status among those with and those without the disease is the same; in cohort studies, this type of bias is most likely and will bias estimates toward no association when exposure is dichotomized. Non-differential underreporting of an exposure with more than two categories may mask a true threshold effect as a dose-response relation and, if a true threshold effect exists, the threshold will be set at too low a level, if the exposure is underreported. Differential misclassification may cause bias in either direction and is particularly likely, when exposure status is reported after the outcome occurred. Misclassification of confounders is an issue that needs special attention by researchers, as failure to measure accurately one or more (strong) confounders may seriously bias the observed results. Misclassification of disease status may also cause bias of estimates of association in either direction. Information bias is probably best prevented during planning of data collection, as there are few and insufficient methods available for correcting inaccurate information.

Childhood growth of singletons conceived following in vitro fertilisation or intracytoplasmic sperm injection: a systematic review and meta-analysis

BACKGROUND

Assisted reproductive techniques are associated with an increased risk of adverse pregnancy outcomes, including low birthweight and intrauterine growth restriction. Yet, the long-term follow-up on the growth of these children is limited.

OBJECTIVE

To systematically review the literature on post-neonatal height and weight among children conceived following in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment, compared with that of children born after spontaneous conception.

SEARCH STRATEGY

A systematic computerised literature search using the online databases PubMed, Embase, and Scopus.

SELECTION CRITERIA

Cohort or case-control studies with an exposed group of singletons conceived following IVF or ICSI along with a control group of spontaneously conceived singletons.

DATA COLLECTION AND ANALYSIS

Studies were reviewed by at least two authors. Meta-analyses were conducted using Cochrane Review Manager. The quality of the studies was assessed with the Newcastle-Ottawa Scale.

MAIN RESULTS

Twenty studies were included, with 13 of these eligible for meta-analyses. The meta-analyses compared 3972 children born after IVF/ICSI with 11 012 spontaneously conceived children and revealed no statistically significant difference in child weight [mean difference (MD) in weight of -160 g; 95% confidence interval (95% CI) -360, 3]. When stratifying by age of child at follow-up, we found a significant lower weight in children aged 0-4 years conceived following IVF/ICSI treatment (MD -180 g; 95% CI -320, -4), but this was no longer significant in children from 5 years of age (MD -160 g; 95% CI -580, 260). The pooled analysis revealed no statistically significant difference in childhood height.

CONCLUSIONS

In vitro fertilisation/ICSI was not associated with long-term weight and height.

TWEETABLE ABSTRACT

Children born following IVF/ICSI do not have impaired long-term weight or height compared with spontaneously conceived children.

Associations between parity and maternal BMI in a population-based cohort study

INTRODUCTION

We aimed to investigate the change in prevalence of overweight and obesity in pregnant Danish women from 2004 to 2012, and investigate whether increasing parity was associated with a change in body mass index (BMI) prevalence.

MATERIAL AND METHODS

We obtained a population-based cohort from the Danish Medical Birth Registry consisting of all Danish women giving birth in 2004-2012 (n = 572 321). This registry contains information on 99.8% of all births in Denmark. We calculated the overall change in prepregnancy BMI status among pregnant women in Denmark, and a multiple linear regression model with adjustment for several potential confounders was used to examine the change in prepregnancy BMI with increasing parity.

RESULTS

In 2004, the prevalence of prepregnancy overweight and obesity (BMI ≥ 25) and obesity alone (BMI ≥ 30) was 31.9 and 11%, respectively. In 2012, the prevalence had reached 34.2 and 12.8%. The mean BMI increased for every additional parity from 23.80 (95% CI 23.77-23.82) in parity group 1 to 26.70 (26.52-26.90) in parity group 5+. A multiple linear regression adjusted for potential confounders showed that women on average gained 0.62 (0.58-0.65) BMI units after every additional birth.

CONCLUSIONS

This study showed a 7.2% increase in overweight and obesity (BMI ≥ 25) and a 16.4% increase in obesity alone (BMI ≥ 30) for pregnant women in Denmark from 2004 to 2012. In addition, an increase in interpregnancy BMI was seen at every additional delivery, suggesting that obesity is an increasing challenge in obstetrics.

Is TWEAK a valid screening questionnaire to identify alcohol risk drinkers among pregnant women in Denmark?

INTRODUCTION

Identification of pregnant alcohol risk drinkers is crucial to prevent adverse birth outcomes. The TWEAK screening instrument has shown promising results for identifying risk drinkers. However, as the effectiveness of the screening questionnaire has only been investigated among American women with mainly low socioeconomic status, we aimed to investigate the ability of TWEAK to identify alcohol risk drinkers among pregnant Danish women.

MATERIAL AND METHODS

During 2000, Danish-speaking women referred to the Midwife Center at Aarhus University Hospital (n = 1554) and Fredericia Hospital (n = 499) for routine antenatal care were invited to participate in the study at their first visit. The women were interviewed about their periconceptional and current drinking habits including average weekly alcohol consumption and binge drinking. Additionally, the women were also asked the questions related to the TWEAK questionnaire.

RESULTS

We found that the sensitivity of TWEAK to identify periconceptional risk drinking was quite low, but its ability to identify risk drinkers during pregnancy was marginally higher. Our results suggested that older age (odds ratio 1.46, 95% confidence interval 0.95-2.23), current smoking (odds ratio 2.33, 95% confidence interval 1.63-3.33), being single (odds ratio 2.38, 95% confidence interval 1.38-4.11) and a TWEAK score with a cut-off score of ≥1 (odds ratio 2.75, 95% confidence interval 2.02-3.76) increased the risk of high-risk drinking during pregnancy.

CONCLUSIONS

In a Danish setting, TWEAK does not seem as an optimal screening tool to identify periconceptional risk drinkers but it may be useful in identifying high-risk drinking during pregnancy.

Coffee, tea and caffeine consumption and risk of primary infertility in women: a Danish cohort study

INTRODUCTION

The aim of this study was to investigate whether consumption of coffee, tea and caffeine affects the risk of primary infertility in women.

MATERIAL AND METHODS

We selected nulliparous Danish women aged 20-29 years from a prospective cohort and retrieved information on coffee and tea consumption from a questionnaire and an interview at enrollment. We assessed the women's fertility by linkage to the Danish Infertility Cohort and retrieved information on children and vital status from the Civil Registration System. All 7574 women included for analysis were followed for primary infertility from the date of enrollment (1991-1993) until 31 December 2010. Analyses were performed with Cox proportional hazard models.

RESULTS

During follow up, primary infertility was diagnosed in 822 women. Compared with never consumers, the risk of primary infertility among women who drank coffee or tea was not affected. The risk of primary infertility was neither associated with an increasing number of daily servings of coffee (hazard ratio 1.00; 95% confidence interval (CI), 0.97-1.03) or tea (hazard ratio 1.01; 95% CI, 0.99-1.03) in consumers only. Concerning total caffeine consumption (from coffee and tea), the risk of infertility was similar among consumers compared with never consumers. Finally, none of the additional daily 100 mg of caffeine affected the risk among consumers only (hazard ratio 1.00; 95% CI 0.98-1.02).

CONCLUSIONS

In this population-based cohort study, not restricted to women seeking pregnancy, we found no association between coffee, tea or total caffeine consumption and the risk of primary infertility in women.

Alcohol binge drinking in early pregnancy and the effect on fetal growth: a cohort study

INTRODUCTION

Alcohol binge drinking is common in early pregnancy and is a well-established risk factor for subsequent child health. Yet, very few studies have investigated the effect on fetal growth. Furthermore, it has been speculated that the timing of binge drinking may be a determining factor for neonatal growth. The objective of this study was to assess the potential effect of binge drinking and different drinking patterns (timing and number of binge drinking episodes) in early pregnancy on fetal growth estimated by birthweight and birth length.

MATERIAL AND METHODS

From 1 March to 31 August 2000, 1836 pregnant Danish women from Aarhus University Hospital and Fredericia Hospital were included in the study and interviewed around the early second trimester about their drinking habits during their pregnancy. Information on anthropometric measures at birth was obtained from the Danish Medical Birth Registry. The potential effect of binge drinking and different drinking patterns was estimated using a multivariate general linear regression model adjusted for potential confounders that were selected a priori based on the currently available scientific literature.

RESULTS

The women who reported any binge drinking gave birth to children with a reduction in birth length of -0.02 cm (95% CI -0.23 to 0.18) and an increase in birthweight of 0.2 g (95% CI -42.8 to 43.2). The number of binge episodes and the timing of these episodes were also not associated with fetal growth.

CONCLUSIONS

The study suggests that binge drinking and different drinking patterns in early pregnancy do not affect fetal growth.

The Association Between Maternal Chronic Inflammatory Bowel Disease and Long-term Health Outcomes in Children-A Nationwide Cohort Study

BACKGROUND

Very little is known about the long-term impact of maternal inflammatory bowel disease (IBD) on the offspring's future health. We aimed to examine whether children born to mothers with IBD had an increased risk of long-term morbidities.

METHODS

In this nationwide register-based cohort study, including all children born alive in Denmark between 1989 and 2013, we investigated the association between maternal IBD and 15 selected disease categories of physical and mental conditions in the offspring. We used multivariate regression models estimating the hazard ratio (HR) of long-term child morbidities.

RESULTS

The cohort comprised 9238 children born to women with IBD (exposed), and 1,371,407 born to women without IBD (unexposed). Median follow-up time among the exposed was 9.7 years (interquartile range [IQR] 4.9-15.7) and 13.8 (interquartile range 7.4-19.9) among the unexposed. In children, who in utero had been exposed to maternal ulcerative colitis, the HR of IBD in the offspring was 4.63 (95% confidence interval, 3.49-6.16). For maternal Crohn's disease, the HR of IBD in the offspring was 7.70 (95% confidence interval, 5.66-10.47). For all other diseases in the offspring, we did not find a significantly increased risk associated with maternal IBD.

CONCLUSIONS

Children born to mothers with IBD are more likely to be diagnosed with IBD themselves, compared with children born to women without IBD. Our data otherwise do not provide evidence for an increased risk of any of the other examined diseases in the offspring.

Parental Infertility, Fertility Treatment, and Childhood Epilepsy: A Population-Based Cohort Study

BACKGROUND

A few studies have indicated an increased risk of epilepsy in children conceived by fertility treatment possibly due to characteristics of the infertile couple rather than the treatment. We therefore aimed to investigate the association between parental infertility, fertility treatment, and epilepsy in the offspring, including the subtypes of epilepsy; idiopathic generalised epilepsy and focal epilepsy.

METHODS

This cohort included all pregnancies resulting in liveborn singletons from the Aarhus Birth Cohort, Denmark (1995-2013). Information on time to pregnancy and fertility treatment was obtained from pregnancy questionnaires in early pregnancy. Children developing epilepsy were identified from the Danish National Patient Register and the Danish National Prescription Registry until 2013. Data were analysed using Cox proportional hazards regression adjusted for potential confounders.

RESULTS

A total of 60 440 pregnancies were included, and 0.8% of the children developed epilepsy.The primary analyses showed no association between parental infertility or fertility treatment, and the overall risk of childhood epilepsy (hazard rate ratios (HRs); 95% confidence intervals (CIs): 1.08 (0.73, 1.60) and 1.04 (0.71, 1.52)). In secondary analyses, both parental infertility and fertility treatment were associated with an increased risk of idiopathic generalised epilepsy (HRs and 95% CIs: 2.25 (1.10, 4.58) and 2.45 (1.26, 4.75)). No association was seen for focal epilepsy.

CONCLUSION

Parental infertility or fertility treatment was not associated with an overall risk of childhood epilepsy. Parental infertility may be associated with an increased risk of idiopathic generalised epilepsy; a subtype of epilepsy believed to be of genetic origin.

Pelvic organ function before and after laparoscopic bowel resection for rectosigmoid endometriosis: a prospective, observational study

OBJECTIVE

To assess urinary, sexual, and bowel function before and after laparoscopic bowel resection for rectosigmoid endometriosis.

DESIGN

Prospectively collected data regarding the function of the pelvic organs.

SETTING

Tertiary endometriosis referral unit, Aarhus University Hospital.

SAMPLE

A cohort of 128 patients who underwent laparoscopic bowel resection for endometriosis.

METHODS

The International Consultation on Incontinence Questionnaire (ICIQ), Sexual Function-Vaginal Changes Questionnaire (SVQ), and the Low Anterior Resection Syndrome (LARS) questionnaire were answered before and after surgery. Non-invasive urodynamic testing was performed.

MAIN OUTCOME MEASURES

Pre- and postoperative function of the pelvic organs was compared, and risk factors for improved/impaired function were identified.

RESULTS

A total of 96.1% of the women completed the 1-year follow-up. A significant decrease (P = 0.002) in bladder filling problems (F-score) was observed 1 year after surgery, primarily caused by a significant decrease in bladder pain (P = 0.0001). No change for urodynamic parameters was observed. A significant increase in overall sexual satisfaction (P = 0.0001) and decrease in worries about sexual life (P = 0.001) was seen 1 year after surgery. Frequency of defecation was significantly increased 1 year after surgery (P = 0.0001), but the overall bowel function measured by LARS score was unchanged. Patients with anastomotic leakage had a significantly higher risk (odds ratio, OR 5.40; P = 0.002) of increased incontinence problems (I-score) 1 year after surgery.

CONCLUSION

A significant and clinically relevant improvement in urinary and sexual function 1 year after laparoscopic bowel resection for endometriosis was found. Except for anastomotic leakage, this could be observed independent of any patient- or treatment-related factor. Apprehension about impairment of urinary and sexual function should not be a contraindication for bowel resection in endometriosis patients.

TWEETABLE ABSTRACT

Rectal resection for endometriosis does not impair urinary and sexual function 1 year after surgery.

Maternal stress before and during pregnancy and subsequent infertility in daughters: a nationwide population-based cohort study

STUDY QUESTION

Is maternal stress following the death of a close relative before or during pregnancy associated with the risk of infertility in daughters?

SUMMARY ANSWER

Compared with unexposed women, women whose mothers had experienced bereavement stress during, or in the year before, pregnancy had a similar risk of infertility overall, but those exposed to maternal bereavement during the first trimester had a higher risk of infertility.

WHAT IS KNOWN ALREADY

Animal studies have shown that prenatal maternal stress results in reduced offspring fertility. In humans, there is evidence that girls who have been prenatally exposed to stress have a more masculine behaviour and a slight delay in having their first child.

STUDY DESIGN, SIZE AND DURATION

This population-based cohort study, included 660 099 females born in Denmark between 1 January 1973 and 31 December 1993 to mothers of Danish origin and with at least one living relative in the exposure window, and followed the women through 31 December 2011.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall, 13 334 women (2.0%) were considered prenatally exposed to stress because their mother had lost a spouse/partner, a child, a parent, or a sibling during pregnancy or in the year before conception. Infertility was defined as any record of infertility treatment or diagnosis of female infertility. We considered the date of onset as the date of the first appearance of any such record. The association between exposure and outcome was examined using hazard ratios (HR) with 95% confidence intervals (CI).

MAIN RESULTS AND THE ROLE OF CHANCE

Based on our definition, 40 052 (6.5%) women were infertile in the follow-up period (median age at the end of follow-up: 26.7 years, maximum age: 39 years). Overall, prenatal exposure to maternal stress was not associated with risk of infertility (adjusted HR = 1.04 [CI: 0.95-1.14]). However, women prenatally exposed during the first trimester had a higher estimated risk (adjusted HR = 1.40 [CI: 1.05-1.86]). These findings were consistent in subgroups defined by the relationship of the mother to the deceased and in several sensitivity analyses, including a sibling-matched analysis, and in analyses restricted to women who were married or cohabitating with a man, or to women born at term.

LIMITATIONS, REASONS FOR CAUTION

We did not have a direct measure of stress, but bereavement due to death of a close relative is likely to be very stressful. We based the timing of exposure on the date of the death of the family member, although the stress may well have started earlier. Infertility was also defined indirectly, and many women in the cohort were too young at the end of the follow-up to have been diagnosed. However, misclassification of the outcome was most likely non-differential, and the similar results from all sensitivity analyses suggest that it is unlikely that the effect observed in first trimester exposure would be due to chance.

WIDER IMPLICATIONS OF THE FINDINGS

Prenatal exposure to maternal stress in the first trimester may affect the later fecundity of daughters.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by a grant from the European Research Council (ERC-2010-StG-260242-PROGEURO) to the ProgEuro project (http://progeuro.au.dk). O.P.-R. is partly supported by a fellowship from Aarhus University and a travel grant from Oticon Fonden. The authors report no conflict of interests.

The association of pre-pregnancy alcohol drinking with child neuropsychological functioning

OBJECTIVE

To examine the effects of pre-pregnancy alcohol drinking on child neuropsychological functioning.

DESIGN

Prospective follow-up study.

SETTING AND POPULATION

154 women and their children sampled from the Danish National Birth Cohort.

METHODS

Participants were sampled based on maternal alcohol consumption before pregnancy. At 5 years of age, the children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised, the Test of Everyday Attention for Children at Five (TEACh-5), and the Movement Assessment Battery for Children (MABC). The Behaviour Rating Inventory of Executive Function (BRIEF) was completed by the mothers and a preschool teacher. Parental education, maternal IQ, prenatal maternal smoking, child's age at testing, child's sex, and maternal alcohol intake during pregnancy were considered potential confounders.

MAIN OUTCOME MEASURES

Performance on the Wechsler Preschool and Primary Scale of Intelligence-Revised, the TEACh-5, the MABC, and the BRIEF.

RESULTS

Intake of 15-21 drinks/week on average prior to pregnancy was not associated with any of the outcomes, but intake of ≥22 drinks/week on average was associated with a significantly lower adjusted mean full scale IQ and lower adjusted means in overall attention and sustained attention score, but not in selective attention score or any of the BRIEF index scores or MABC scores.

CONCLUSIONS

Intake of ≥22 drinks/week before pregnancy was associated with lower mean full scale IQ, overall attention and sustained attention. Assessment of pre-pregnancy drinking provides additional information regarding potential prenatal alcohol exposure and its implications for child neurodevelopment.

Visceral syndrome in endometriosis patients

OBJECTIVE

Pain related to bowel and bladder function is seen more often in endometriosis. This study explored whether employed endometriosis patients experience multiple visceral symptoms more often than reference women without the disease.

STUDY DESIGN

In a cohort study, 610 patients with diagnosed endometriosis and 751 reference women completed an electronic survey based on the EHP-30 questionnaire. Percentages were reported for all data. Principal component analysis was used to find underlying structures of correlations among variables, and Cronbach's alpha reliability analysis was used to demonstrate internal consistency of each scale. The level of statistical significance was set at p<0.025 in all the analyses.

RESULTS

Principal component analysis pointed at a specific visceral symptom-complex relating to the abdominal organs. This correlation was called "visceral syndrome" and consisted of the seven symptoms; "abdominal pain with no relation to menstruation", "pain during urination", "pain during defecation", "constipation or diarrhea", "irregular bleeding", "nausea or vomiting" and "feeling tired/lack of energy", with a Cronbach's alpha value α=0.85. More women with endometriosis than reference women suffered between five and seven symptoms from the visceral syndrome (22.7% vs. 2.7%) and more women with endometriosis compared to women with pain from other conditions suffered between five and seven symptoms from the visceral syndrome (22.7% vs. 3.2%).

CONCLUSION

These data indicate that a significant number of endometriosis patients suffer from a specific symptom correlation, which is uncommon in women without the disease. These findings and previous data may suggest the occurrence of a visceral syndrome in endometriosis.

Maternal pre-pregnancy BMI and intelligence quotient (IQ) in 5-year-old children: a cohort based study

BACKGROUND

An association between maternal pre-pregnancy BMI and childhood intelligence quotient (IQ) has repeatedly been found but it is unknown if this association is causal or due to confounding caused by genetic or social factors.

METHODS

We used a cohort of 1,783 mothers and their 5-year-old children sampled from the Danish National Birth Cohort. The children participated between 2003 and 2008 in a neuropsychological assessment of cognitive ability including IQ tests taken by both the mother and the child. Linear regression analyses were used to estimate the associations between parental BMI and child IQ adjusted for a comprehensive set of potential confounders. Child IQ was assessed with the Wechsler Primary and Preschool Scales of Intelligence--Revised (WPPSI-R).

RESULTS

The crude association between maternal BMI and child IQ showed that BMI was adversely associated with child IQ with a reduction in IQ of -0.40 point for each one unit increase in BMI. This association was attenuated after adjustment for social factors and maternal IQ to a value of -0.27 (-0.50 to -0.03). After mutual adjustment for the father's BMI and all other factors except maternal IQ, the association between paternal BMI and child IQ yielded a regression coefficient of -0.26 (-0.59 to 0.07), which was comparable to that seen for maternal BMI (-0.20 (-0.44 to 0.04)).

CONCLUSION

Although maternal pre-pregnancy BMI was inversely associated with the IQ of her child, the similar association with paternal BMI suggests that it is not a specific pregnancy related adiposity effect.