Identification of women at high risk of postpartum psychiatric episodes: A population-based study quantifying relative and absolute risks following exposure to selected risk factors and genetic liability

BACKGROUND

We quantified relative and absolute risks of postpartum psychiatric episodes (PPE) following risk factors: Young age, past personal or family history of psychiatric disorders, and genetic liability.

METHODS

We conducted a register-based study using the iPSYCH2012 case-cohort sample. Exposures were personal history of psychiatric episodes prior to childbirth, being a young mother (giving birth before the age of 21.5 years), having a family history of psychiatric disorders, and a high (highest quartile) polygenic score (PGS) for major depression. PPE was defined within 12 months postpartum by prescription of psychotropic medication or in- and outpatient contact to a psychiatric facility. We included primiparous women born 1981-1999, giving birth before January 1st, 2016. We conducted Cox regression to calculate hazard ratios (HRs) of PPE, absolute risks were calculated using cumulative incidence functions.

RESULTS

We included 8174 primiparous women, and the estimated baseline PPE risk was 6.9% (95% CI 6.0%-7.8%, number of PPE cases: 2169). For young mothers with a personal and family history of psychiatric disorders, the absolute risk of PPE was 21.6% (95% CI 15.9%-27.8%). Adding information on high genetic liability to depression, the risk increased to 29.2% (95% CI 21.3%-38.4%) for PPE.

CONCLUSIONS

Information on prior personal and family psychiatric episodes as well as age may assist in estimating a personalized risk of PPE. Furthermore, additional information on genetic liability could add even further to this risk assessment.

Social well-being and problematic school absence among Danish adolescents: A nationwide cross-sectional study

AIM

Adolescents' well-being and school absence are important factors for public health. The aim of this study was to examine the association between social well-being and problematic school absence among Danish adolescents in the ninth grade, as well as to examine potential sex differences, using a large cohort of adolescents.

METHODS

In this cross-sectional study, information on social well-being was obtained from the yearly Danish National Well-being Questionnaire mandatory in compulsory school. Data on school absence was obtained from the Ministry of Children and Education. The study population comprised 203,570 adolescents in the school years 2014/2015 to 2019/2020. The association between social well-being and problematic school-absence was analysed using logistic regression. A stratified analysis was made to investigate potential sex differences.

RESULTS

A total of 17,555 (9.16%) adolescents had problematic school absence, defined as >10% illegal absence and/or sickness absence in the ninth grade. Adolescents with low social well-being had higher odds for having problematic school absence compared with adolescents with high social well-being, adjusted odds ratio=2.22 (95% confidence interval 2.10-2.34). When stratifying for sex, the association was strongest for girls. The results remained after adjustment for parents' educational level and family structure.

CONCLUSIONS

Associations between adolescents' social well-being and problematic school absence were found, where girls had the strongest association. These findings might provide knowledge about social well-being as an important factor for problematic school absence, while underlining the importance of early focus and prevention, which is of importance for both the adolescents and society.

Evaluating the performance of the Charlson Comorbidity Index (CCI) in fracture risk prediction and developing a new Charlson Fracture Index (CFI): a register-based cohort study

The Charlson Comorbidity Index (CCI) may be applicable for predicting fracture risk since several diagnoses from the index are predictors of fracture. Main results were that the CCI was updated to predict risk of hip fracture with fair precision and that the index could be useful in detecting high-risk individuals.

PURPOSE

Several of the Charlson Comorbidity Index (CCI) diagnoses are validated predictors of fracture. The purpose of this study was to evaluate the performance of the CCI 1987 by Charlson et al. and of the CCI 2011 by Quan et al. in predicting major osteoporotic fracture (MOF) and hip fracture (HF). Furthermore, it was examined whether the index could be modified to improve fracture risk prediction.

METHODS

The study population included the entire Danish population aged 45 + years as per January 1, 2018. The cohort was split randomly 50/50 into a development and a validation cohort. CCI diagnoses and fracture outcomes were identified from hospital diagnoses. The weighting of diagnoses was updated in a new Charlson Fracture Index (CFI) using multivariable logistic regression. Predictive capabilities of the CCI 1987, the updated CCI 2011 and the new Charlson Fracture index were evaluated in the validation cohort by receiver operating characteristics (ROC) curves and area under the curve (AUC).

RESULTS

In the validation cohort, the 1987 and 2011 CCIs resulted in AUCs below or around 0.7 in prediction of MOF and HF in both sexes. The CFI resulted in AUCs < 0.7 in prediction of MOF in both sexes. In prediction of HF, the CFI resulted in AUC of 0.755 (95% CI 0.749; 0.761) in women and 0.782 (95% CI 0.772; 0.793) in men.

CONCLUSION

The 1987 and 2011 CCIs showed overall poor accuracy in fracture risk prediction. The CFI showed fair accuracy in prediction of HF in women and in men.

Association of Rheumatoid Arthritis in Pregnancy With School Performance of Offspring: A Danish Nationwide Register-Based Study

OBJECTIVE

To examine the overall cognitive development of children exposed to maternal rheumatoid arthritis (RA) in utero by comparing their school test scores to those of their peers.

METHODS

Children born in Denmark during 1995-2008 and listed in the National School Test Register were included (n = 738,862). Children exposed to maternal RA were identified through linkage of national registers. In separate analyses, exposure was subdivided according to maternal serostatus. Preclinical maternal RA was included as a separate exposure. The Danish national school tests are mandatory standardized tests. Results from all reading tests (grades 2, 4, 6, and 8) and mathematics tests (grades 3 and 6) from 2010-2017 were included. Test scores were compared according to maternal RA exposure for each test separately using linear regressions.

RESULTS

We identified 934 children exposed to maternal RA in utero. There were no differences in reading test scores between maternal RA exposed and unexposed children. RA exposed children scored poorer in both mathematics tests (adjusted differences of mean score -0.14 SD (95% confidence interval [95% CI] -0.23, -0.06) and -0.16 SD (95% CI -0.26, -0.07). There was no appreciable difference between children by maternal RA serostatus. Children exposed to preclinical RA (n = 589) showed the same pattern of performance as children exposed to RA.

CONCLUSION

RA-exposed children scored slightly poorer in mathematics tests but performed as well as their unexposed peers in the reading tests. The results do not suggest that RA in pregnancy has a major impact on offspring school performance.

Maternal rheumatoid arthritis during pregnancy and neurodevelopmental disorders in offspring: a systematic review

Objective: To summarize the available literature on in utero exposure to maternal rheumatoid arthritis (RA) and its influence on the risk of neurodevelopmental disorders (NDDs) in offspring.Method: We conducted a systematic literature review and assessed the internal validity of studies with the Newcastle Ottawa Scale tool.Results: Six studies were included. Three reported on autism spectrum disorders; one cohort study indicated a slightly elevated risk, and two case-control studies reported too few cases for risk assessment. Two large cohort studies reported elevated hazard ratios for epilepsy in offspring, in overlapping populations. One study on attention deficit hyperactivity disorder (ADHD) reported higher odds for maternal RA during pregnancy, among children with ADHD.Conclusion:Few studies were found specifically studying maternal RA during pregnancy and NDDs in offspring. The studies pointed towards a moderately higher risk of these outcomes; however, reporting bias appears to be a problem. Additional studies of appropriate design and power are needed.

Divorce or Separation Following Postpartum Psychiatric Episodes: A Population-Based Cohort Study

Objective: Psychiatric disorders are an established risk factor for divorce or separation. Despite the fact that 10%-15% of new mothers experience postpartum psychiatric episodes (PPEs), no previous studies have investigated the effects of PPEs on the probability of divorce in these new families. Therefore, this study aimed to investigate and quantify the probability of subsequent divorce/separation among women with either mild/moderate or severe PPE compared to mothers without PPE. Methods: This cohort study based on the national Danish registers included all cohabitating, primiparous women without previous psychiatric history who gave birth from 1996 through 2014. At 6 months postpartum, each woman's PPE status was evaluated and categorized as follows: (1) mild/moderate PPE (prescription of psychotropic medication-Anatomical Therapeutic Chemical Classification codes N03-N07), (2) severe PPE (psychiatric inpatient or outpatient treatment-International Classification of Disease, 10th Edition codes F00-F99, excluding codes for organic mental disorders, substance abuse, and mental retardation), and (3) no PPE (reference group). Subsequently, the status of cohabitation was assessed a maximum of 5 times (every January 1). Results: A total of 266,771 new mothers were included; 4,442 had a first mild/moderate PPE and 1,141 had a first severe PPE within 6 months postpartum. Compared to mothers without PPE, women with mild/moderate PPE had a significantly higher probability of later divorce (adjusted hazard ratio [HR] = 1.23; 95% CI, 1.15-1.31); for women with severe PPE, the probability was even greater (adjusted HR = 1.64; 95% CI, 1.45-1.85). Conclusions: Women experiencing their first-ever PPE following childbirth have a higher probability of divorce in the years following their diagnosis than mothers without PPE. Further, this study showed a dose-response relationship between the severity of PPE and the probability of divorce.

Maternal pre-pregnancy overweight and infertility in sons and daughters: A cohort study

INTRODUCTION

Overweight and obesity in pregnancy is increasing worldwide and may harm the developing fetus, including its future reproductive health. We therefore studied the association between in utero exposure to maternal overweight and obesity and infertility in adulthood. No studies have previously assessed this association.

MATERIAL AND METHODS

We performed a cohort study with 9232 adult sons and daughters whose mothers were enrolled in the Danish Healthy Habits for Two cohort during pregnancy in 1984-87. Participants were sons and daughters followed in the Danish In-Vitro-Fertilization-Register and Danish National Patient Register until February 2018 for diagnoses of infertility.

RESULTS

In total, 1203 (13%) sons and daughters were born to mothers with a body mass index (BMI) >25 kg/m² ; 871 (9.4%) of the participants were identified as being infertile during follow-up. Sons of overweight mothers had slightly increased odds of infertility compared with sons of mothers with normal body weight (BMI 18.5-24.9 kg/m² , adjusted odds ratio 1.4, 95% confidence interval [CI] 1.0-1.9). Cubic spline analyses with continuous BMI levels showed increasing odds with higher levels of BMI; however, for BMI >29 kg/m² the confidence intervals were too wide to draw conclusions. No association between maternal overweight and infertility was found among daughters (adjusted odds ratio 0.9, 95% CI 0.7-1.2)).

CONCLUSIONS

Sons born to overweight mothers had higher odds of infertility compared with sons of normal weight mothers. No association between maternal overweight and infertility was observed in daughters. Prevention of overweight during pregnancy may be an important tool to preserve fecundity in future generations.

General medical conditions and mortality in women with postpartum psychiatric disorders

BACKGROUND

Psychiatric patients have an increased risk of general medical conditions and mortality, but no study has systematically explored these outcomes among women with mental disorders following childbirth (postpartum psychiatric disorders: PPD). Therefore, we aimed to investigate the risk of subsequent general medical conditions and mortality in women with a broad spectrum of PPD.

METHODS

This register-based cohort study followed all Danish women born after January 1, 1960, until January 1, 2016. The exposure of interest was (i) mild-moderate PPD: first-ever prescription of psychotropic medication (ATC codes: N03-N07) and (ii) severe PPD: first-ever in- or out-patient contact to a psychiatric facility, both within six months postpartum. Outcomes of interest were (i) hospital-registered chronic medical conditions and (ii) mortality from natural and unnatural causes. We included 1 841 949 women representing 22 615 310 person-years at risk.

RESULTS

Among 15 852 women with mild-moderate PPD and 4266 women with severe PPD, we found a higher risk of any subsequent general medical condition (mild-moderate PPD: IRR 1.25; 95% CI 1.20-1.31 and severe PPD: IRR 1.35; 95% CI: 1.24-1.48) when compared to the female background population. Mortality from both natural and unnatural causes was higher in both groups: Mild-moderate PPD: natural causes MRR 1.37; 95% CI: 1.17-1.61; unnatural causes MRR 1.52; 95% CI: 1.10-2.11, and severe PPD: natural causes MRR 1.42; 95% CI 1.02-2.00, and unnatural causes MRR 5.05; 95% CI: 3.40-7.51.

CONCLUSIONS

This first overview of general medical prognosis in PPD shows that women at either end of the spectrum are at increased risk of subsequent chronic medical conditions and overall mortality.

Systemic lupus erythematosus during pregnancy is not associated with school performance in offspring - A Danish population-based study

INTRODUCTION

Systemic lupus erythematosus (SLE) in pregnancy is considered a risk factor for a range of adverse outcomes in the offspring. Studies have indicated increased risk of neurodevelopmental disorders such as autism spectrum disorders, dyslexia and ADHD. However, the overall long-term cognitive development of children born to women with SLE has scarcely been examined. In this study, we compare test scores from the Danish National School Tests of children born to women SLE with children of the background population.

METHODS

We included all singleton children born in Denmark between 1995 and 2008, who were listed in the Danish National School Test Register (n=738,862). Children born to women with SLE were identified through linkage of national healthcare registers. We assessed the children's performance in the national school tests between 2nd and 8th grade, in reading and mathematics. Information on the mothers' redeemed prescriptions in pregnancy was included in stratified analyses. Differences of mean test scores were derived from linear regressions and compared according to maternal SLE status, and predefined categories of medication exposures.

RESULTS

In total, 312 (0.04%) children were born to mothers with SLE. There were no differences in performance in neither reading nor mathematics tests between those born to mothers with SLE and children born to mothers without SLE. When stratifying on medication exposures among children whose mothers had SLE, there was a non-significant tendency towards poorer results among those exposed to hydroxychloroquine and/or immunosuppressants (n=31), compared to those not exposed to these medications. A similar tendency was not observed among children whose mothers received hydroxychloroquine for non-SLE reasons (n=1,235).

CONCLUSION

This study indicates no major harmful effect on the child's neurocognitive development from exposure in utero to SLE, hydroxychloroquine and/or immunosuppressants, as measured by school performance.

Cardiovascular biomarkers in the evaluation of patent ductus arteriosus in very preterm neonates: A cohort study

BACKGROUND

The evaluation of the patent ductus arteriosus (PDA) in the very premature neonate is a challenge. Echocardiography provides an interpretation of the hemodynamic condition. It is however, only a snapshot. Biomarkers may represent a physiological response to the hemodynamic alterations brought on by the PDA and may add to the identification of the clinical significant PDA.

AIM

To investigate the association between mid regional proadrenomodulin (MR-proADM), N-terminal pro b-type natriuretic peptide (NT-proBNP), mid regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro endothelin-1 (CT-proET1) and copeptin and echocardiographic measures of PDA.

STUDY DESIGN

Cohort study with echocardiography performed on day 3 and 6. Blood samples from day 3.

SUBJECT

139 consecutive neonates born at a gestational age <32 weeks.

OUTCOME MEASURES

The main outcomes were presence of a PDA day 3 and 6, PDA diameter, left atrium to aorta ratio (LA:Ao-ratio), and descending aorta diastolic flow (DADF).

RESULTS

Adjusted plasma levels of all investigated biomarkers, except CT-proET1, were found to be associated with both PDA diameter and LA:Ao-ratio, and also the presence of a large PDA. CT-proET1 and copeptin was found to be associated with abnormal DADF. Using pre-specified cut-off values NT-proBNP and MR-proANP day 3 seemed to be of value in identifying a large PDA day 3 and 6 in very preterm neonates.

CONCLUSION

Among the investigated biomarkers NT-proBNP and MR-proANP performed best in relation to echocardiographic markers of PDA severity in very preterm neonates.

Reproductive life in women with celiac disease; a nationwide, population-based matched cohort study

STUDY QUESTION

How does celiac disease (CD) influence women's reproductive life, both prior to and after the diagnosis?

SUMMARY ANSWER

Prior to the diagnosis of CD, an increased risk of adverse pregnancy outcomes was seen, whereas after the diagnosis, no influence on reproductive outcomes was found.

WHAT IS KNOWN ALREADY

CD has been associated with several conditions influencing female reproduction and pregnancy outcomes including spontaneous abortion and stillbirth.

STUDY DESIGN, SIZE, DURATION

A nationwide matched cohort study following 6319 women diagnosed with CD and 63166 comparison women and identifying reproductive events between the ages of 15 and 50 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Through linkage of several Danish national health registers, we identified all women diagnosed with CD between 1977 and 2016. We identified an age- and sex-matched comparison cohort and obtained data on reproductive outcomes for both cohorts. Adjusted stratified Cox and logistic regression models were used to estimate differences in reproductive outcomes between women with and without CD.

MAIN RESULTS AND THE ROLE OF CHANCE

Comparing women with diagnosed CD with the non-CD women, the chance of pregnancy, live birth and risk of stillbirth, molar and ectopic pregnancy, spontaneous abortion and abortion due to foetal disease was the same. However, prior to being diagnosed, CD women had an excess risk of spontaneous abortion equal to 11 extra spontaneous abortions per 1000 pregnancies (adjusted odds ratio (OR) = 1.12, 95% CI: 1.03, 1.22) and 1.62 extra stillbirths per 1000 pregnancies (adjusted OR = 1.57, 95% CI: 1.05, 2.33) compared with the non-CD women. In the period 0-2 years prior to diagnosis fewer pregnancies occurred in the undiagnosed CD group, equal to 25 (95% CI: 20-31) fewer pregnancies per 1000 pregnancies compared to the non-CD group and in addition, fewer undiagnosed CD women initiated ART-treatment in this period, corresponding to 4.8 (95% CI: 0.9, 8.7) fewer per 1000 women compared to non-CD women.

LIMITATIONS, REASONS FOR CAUTION

Validity of the diagnoses in the registers was not confirmed, but reporting to the registers is mandatory for all hospitals in Denmark. Not all spontaneous abortions will come to attention and be registered, whereas live- and stillbirths, ectopic and molar pregnancies and abortion due to foetal disease are unlikely not to be registered. We adjusted for several confounding factors but residual confounding cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that undiagnosed CD can affect female reproduction and the focus should be on early detection of CD in risk groups.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Health Research Fund of Central Denmark Region and The Hede Nielsens Foundation, Denmark. The authors report no conflicts of interest in this work.

Unrecognised coeliac disease among men and women undergoing fertility treatment: A screening study

BACKGROUND

Coeliac disease is an autoimmune disease triggered by dietary gluten and has been associated with several conditions influencing female and male reproduction. Due to unspecific symptoms, coeliac disease can be unrecognised for years.

OBJECTIVE

To estimate the prevalence of unrecognised coeliac disease among couples referred to fertility treatment.

METHODS

Cross-sectional screening for coeliac disease in men and women referred to fertility treatment using IgA tissue transglutaminase antibodies as a marker of coeliac disease and small-bowel biopsies to confirm the diagnosis. Participants answered a questionnaire on gluten intake, gastrointestinal symptoms and reproductive history.

RESULTS

A total of 893 participants (51% women) were screened and eight were coeliac disease antibody positive. Small-bowel biopsies were obtained from seven antibody positive participants and unrecognised coeliac disease was confirmed in one woman and three men, corresponding to a prevalence of 0.45% (95% confidence interval 0.12-1.14). The total prevalence, combining already diagnosed and unrecognised CD cases, was 0.63% (95% confidence interval 0.29-1.12).

CONCLUSION

The prevalence of unrecognised coeliac disease in a group of infertile patients was equivalent to that of the Danish general population and low compared with that observed in the majority of other screening studies of infertile patients. Surprisingly, it should be noted that more men than women had coeliac disease. This result does not support a need for routine screening among infertile patients.

Temporal trends of lipophilic persistent organic pollutants in serum from Danish nulliparous pregnant women 2011-2013

The use of the lipophilic persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs) and several organochlorine pesticides (OCPs) has been prohibited for more than 30 years. In this study, we present the temporal trends of the lipophilic POP serum concentrations in Danish nulliparous pregnant women between 2011 and 2013. We randomly selected 197 pregnant women (gestational age 11-13) from the Aarhus Birth Cohort. The concentrations of the lipophilic POPs in the serum samples were analyzed using gas chromatography. The concentrations were corrected for total serum lipids. The statistical analysis was performed by regression analysis with adjustment for age, BMI, gestational age at blood draw, and smoking status. The serum concentrations of PCB 118, 138, 153, 156, 170, 180, 187, and hexachlorobenzen, trans-nonachlor, β-hexachlorocyclohexane (β-HCH), and p,p'-dichlorodiphenyldichloroethylene were lower in 2013 than in 2011. However, the oxychlordane concentration was lowest in 2011. The serum levels of most lipophilic POPs followed downward trends during the study period, which was expected, as these compounds has been banned for many years. The upward trend of oxychlordane was unexpected and presumably a chance finding.

Maternal serum concentrations of perfluoroalkyl acids in five international birth cohorts

BACKGROUND

Perfluoroalkyl acids (PFAAs) are persistent and bioaccumulating compounds, which are spread all over the globe. We aimed to compare the PFAA concentrations in serum from pregnant women in five birth cohorts from four countries (Denmark, China, Norway, and Greenland).

METHODS

Serum samples were obtained from the following five birth cohorts including a total of 4718 pregnant women: the Danish National Birth Cohort (DNBC, years 1996-2002, Denmark), the Aarhus Birth Cohort (ABC, years 2008-2013, Denmark), the Shanghai Birth Cohort (SBC, years 2013-2015, China), the Northern Norway Mother-Child Contaminant Cohort (MISA, years 2007-2009, Norway), and the Greenlandic Birth Cohort (ACCEPT, years 2010-2013, Greenland). The samples were analyzed using liquid chromatography triple-quadrupole mass spectrometry. To ensure comparability, all samples except for the MISA samples were measured in the same laboratory. We adjusted the log-transformed PFAA concentrations for age and parity using analysis of covariance.

RESULTS AND DISCUSSION

The geometric mean (GM) of the summed concentrations of the seven most abundant PFAAs (∑PFAA) was 35ng/mL in the DNBC, 25 ng/mL in the SBC, 18ng/mL in the ACCEPT, 12ng/mL in the MISA cohort, and 12ng/mL in the ABC. The DNBC concentration was highest presumably because these samples were taken in earlier years (i.e. 1996-2002) than the samples from the other cohorts (i.e. 2007-2015), and at a time when the production of PFAAs were at the highest. When excluding the DNBC samples, we found that the concentrations of all the perfluorinated sulfonic acids (PFSAs) and one of the four perfluorinated carboxylic acids (PFCAs) were highest in the Greenlandic women, whereas the other three PFCAs were highest in the Chinese women.

CONCLUSION

The concentration and composition of serum PFAAs were similar for the Danish ABC women and the Norwegian MISA women but were otherwise different across the cohorts. The different exposure profiles might partly be related to differences in lifestyle and diet. As the concentrations and compositional patterns vary between the countries, we suggest that the health implications associated with high PFAA exposure might also differ between the countries.

Diagnosing gestational diabetes mellitus in the Danish National Birth Cohort

INTRODUCTION

The Danish National Birth Cohort (DNBC) contains comprehensive information on diet, lifestyle, constitutional and other major characteristics of women during pregnancy. It provides a unique source for studies on health consequences of gestational diabetes mellitus. Our aim was to identify and validate the gestational diabetes mellitus cases in the cohort.

MATERIAL AND METHODS

We extracted clinical information from hospital records for 1609 pregnancies included in the Danish National Birth Cohort with a diagnosis of diabetes during or before pregnancy registered in the Danish National Patient Register and/or from a Danish National Birth Cohort interview during pregnancy. We further validated the diagnosis of gestational diabetes mellitus in 2126 randomly selected pregnancies from the entire Danish National Birth Cohort. From the individual hospital records, an expert panel evaluated gestational diabetes mellitus status based on results from oral glucose tolerance tests, fasting blood glucose and Hb1c values, as well as diagnoses made by local obstetricians.

RESULTS

The audit categorized 783 pregnancies as gestational diabetes mellitus, corresponding to 0.89% of the 87 792 pregnancies for which a pregnancy interview for self-reported diabetes in pregnancy was available. From the randomly selected group the combined information from register and interviews could correctly identify 96% (95% CI 80-99.9%) of all cases in the entire Danish National Birth Cohort population. Positive predictive value, however, was only 59% (56-61%).

CONCLUSIONS

The combined use of data from register and interview provided a high sensitivity for gestational diabetes mellitus diagnosis. The low positive predictive value, however, suggests that systematic validation by hospital record review is essential not to underestimate the health consequences of gestational diabetes mellitus in future studies.

Maternal serum concentrations of perfluoroalkyl acids in five international birth cohorts

BACKGROUND

Perfluoroalkyl acids (PFAAs) are persistent and bioaccumulating compounds, which are spread all over the globe. We aimed to compare the PFAA concentrations in serum from pregnant women in five birth cohorts from four countries (Denmark, China, Norway, and Greenland).

METHODS

Serum samples were obtained from the following five birth cohorts including a total of 4718 pregnant women: the Danish National Birth Cohort (DNBC, years 1996-2002, Denmark), the Aarhus Birth Cohort (ABC, years 2008-2013, Denmark), the Shanghai Birth Cohort (SBC, years 2013-2015, China), the Northern Norway Mother-Child Contaminant Cohort (MISA, years 2007-2009, Norway), and the Greenlandic Birth Cohort (ACCEPT, years 2010-2013, Greenland). The samples were analyzed using liquid chromatography triple-quadrupole mass spectrometry. To ensure comparability, all samples except for the MISA samples were measured in the same laboratory. We adjusted the log-transformed PFAA concentrations for age and parity using analysis of covariance.

RESULTS AND DISCUSSION

The geometric mean (GM) of the summed concentrations of the seven most abundant PFAAs (∑PFAA) was 35ng/mL in the DNBC, 25 ng/mL in the SBC, 18ng/mL in the ACCEPT, 12ng/mL in the MISA cohort, and 12ng/mL in the ABC. The DNBC concentration was highest presumably because these samples were taken in earlier years (i.e. 1996-2002) than the samples from the other cohorts (i.e. 2007-2015), and at a time when the production of PFAAs were at the highest. When excluding the DNBC samples, we found that the concentrations of all the perfluorinated sulfonic acids (PFSAs) and one of the four perfluorinated carboxylic acids (PFCAs) were highest in the Greenlandic women, whereas the other three PFCAs were highest in the Chinese women.

CONCLUSION

The concentration and composition of serum PFAAs were similar for the Danish ABC women and the Norwegian MISA women but were otherwise different across the cohorts. The different exposure profiles might partly be related to differences in lifestyle and diet. As the concentrations and compositional patterns vary between the countries, we suggest that the health implications associated with high PFAA exposure might also differ between the countries.

Prenatal exposure to persistent organic pollutants and offspring allergic sensitization and lung function at 20 years of age

BACKGROUND

Prenatal exposures to persistent organic pollutants (POPs) have been associated with asthma medication use and self-reported symptoms, but associations with lung function and allergic sensitization have been minimally explored. The aim of the study was to examine the associations between prenatal exposures to POPs and allergic sensitization and lung function in 20-year-old offspring.

METHODS

In a Danish cohort of 965 pregnant women established in 1988-1989, six polychlorinated biphenyl (PCB) congeners, hexachlorobenzene (HCB), and dichlorodiphenyldichloroethylene (p,p'-DDE) were quantified in archived maternal serum drawn in gestational week 30 (n = 872). Among those with available maternal exposure information, at age 20, 421 offspring attended attended a clinical examination including measurements of allergic sensitization (serum-specific IgE ≥ 0.35 kUA /L) (n = 418) and lung function [forced expiratory volume in one second (FEV1 ) and forced vital capacity (FVC)] (n = 414).

RESULTS

There were no associations between maternal concentrations of POPs and offspring allergic sensitization at 20 years of age. Maternal concentrations of POPs were, however, positively associated with offspring airway obstruction (FEV1 /FVC < 75%). Compared to offspring in the first tertile of exposure, offspring in the third tertile of dioxin-like PCB exposure had an OR of 2.96 (95% CI: 1.14-7.70). Similar associations for non-dioxin-like PCBs, HCB, and p,p'-DDE were 2.68 (1.06-6.81), 2.63 (1.07, 6.46), and 2.87 (1.09, 7.57), respectively. No associations were observed with reduced lung function (FEV1 % of predicted value < 90%).

CONCLUSION AND CLINICAL RELEVANCE

Our data indicate that prenatal exposure to POPs appears to be associated with airway obstruction but not allergic sensitization at 20 years of age. The findings support that chronic obstructive lung diseases may have at least part of their origins in early life.

Determinants of serum levels of perfluorinated alkyl acids in Danish pregnant women

Humans are exposed to perfluorinated alkyl acids (PFAAs) from food, drinking water, air, dust, and consumer products. PFAAs are persistent and bio-accumulative. In the present study, we aimed to establish how the serum levels of PFAAs differ according to age, pre-pregnancy body mass index (BMI), previous miscarriages, educational level, country of birth, smoking, and alcohol intake. We included 1438 Danish pregnant nulliparous women from the Aarhus Birth Cohort. The women gave a blood serum sample between week 11 and 13 of pregnancy. Sixteen PFAAs were extracted from serum using solid phase extraction and analyzed by liquid chromatography/tandem mass spectrometry. Multivariable linear regression analysis was used to determine the associations between individual characteristics of the women and their levels of seven PFAAs that were detected in at least 50% of the samples. The total concentration of the PFAAs (∑PFAA) was higher in older women. On average, normal weight women had a higher ∑PFAA level than underweight, overweight, and obese women. Higher levels were also observed for women without previous miscarriages, women with a high educational level, women born in Denmark (as opposed to women born elsewhere but currently living in Denmark), non-smokers, and women who consumed alcohol before or during pregnancy. These associations were similar for all the studied PFAAs, although the levels of perfluoroundecanoic acid varied more across the categories of age, BMI, education, smoking, and alcohol consumption than any other PFAAs measured.

Time trends of perfluorinated alkyl acids in serum from Danish pregnant women 2008-2013

We aimed to estimate the levels and time trends of perfluorinated alkyl acids (PFAAs) in serum of 1533 Danish pregnant nulliparous women between 2008 and 2013. The selection criterion of only including nulliparous women was chosen to avoid confounding from parity. The serum samples were analyzed for sixteen PFAAs using solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS). We investigated the time trends for seven PFAAs, which were detected in more than 50% of the samples: perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnA). We found that the serum levels of all seven PFAAs decreased during the period from 2008 to 2013; on average PFHxS decreased with 7.0% per year, PFHpS with 14.8%, PFOS with 9.3%, PFOA with 9.1%, PFNA with 6.2%, PFDA with 6.3%, and PFUnA with 7.1% per year. Adjustment for maternal age, body mass index (BMI), educational level and gestational age at blood sampling did not change the time trends much. To our knowledge, we are the first to report decreasing trends of PFNA, PFDA and PFUnA since year 2000, thereby indicating that the phase-out of these compounds are beginning to show an effect on human serum levels.

Management of cerebral palsy varies by healthcare region

INTRODUCTION

Cerebral palsy (CP) is the most common type of motor disability in childhood. The aim of the present paper was to describe regional differences in the management of CP in school-aged children in Denmark.

METHODS

This was a cross-sectional study based on the Danish Cerebral Palsy Registry. The parents of 462 children answered a questionnaire about their child's treatment and the family's characteristics. Descriptive and logistic regression analyses were performed for every treatment modality, stratified by the Gross Motor Function Classification System (GMFCS) level and adjusted for family and child characteristics.

RESULTS

Significant regional differences were found regarding the provision of occupational therapy at all GMFCS levels, speech therapy at GMFCS levels II-V and orthopaedic surgery at GMFCS levels I and III-V. No regional differences were observed in the frequency of physiotherapy. We found no regional differences in the severity of disability.

CONCLUSIONS

Regional differences in the management of CP cannot be explained by social differences or differences in the severity of the disability.

FUNDING

This study was funded by the Research Foundation from the Central Denmark Region and the Department of Clinical Medicine at Aarhus University Hospital, the Augustinus Foundation, the Bevica Foundation, the Dagmar Marshalls Foundation, the Ludvig and Sara Elsass Foundation, and the Civil Engineer Frode V. Nyegaard's and his Wife's Foundation.

TRIAL REGISTRATION

not relevant.

Impact of child and family characteristics on cerebral palsy treatment

AIM

The aim of the study was to describe the relationship between the child's and family's characteristics and the most common treatment modalities in a national population-based sample of 8- to 15-year-old children with cerebral palsy.

METHOD

A cross-sectional study, based on the Danish Cerebral Palsy Registry. The parents of 462 children answered a questionnaire about their child's treatment and the family's characteristics (living with a single parent, having siblings, living in a city, parental education level). Descriptive and logistic regression analyses were performed for every treatment modality, stratified by Gross Motor Function Classification System (GMFCS) level.

RESULTS

An IQ below 85 was associated with weekly therapy in GMFCS level I (adjusted odds ratio [ORadj ] 2.5 [CI 1.1-5.7]) and the use of oral spasmolytics in GMFCS levels III to V (ORadj 3.1 [CI 1.3-7.4]). Older children in GMFCS levels III to V used daily orthoses less frequently (ORadj 0.7 [CI 0.6-0.9] per year). Of all of the family characteristics studied, only the parents' education level had significant associations with more than one treatment modality.

INTERPRETATION

A child's cognitive function showed an impact on treatment of the motor impairment in children 8 to 15 years of age with cerebral palsy. Parental education level may influence the choice of treatment.

Disproportionate fetal growth and the risk for congenital cerebral palsy in singleton births

OBJECTIVE

To investigate the association between proportionality of fetal and placental growth measured at birth and the risk for congenital cerebral palsy (CP).

STUDY DESIGN

We identified all live-born singletons born in Denmark between 1995 and 2003 and followed them from 1 year of age until December 31st, 2008. Information on four indices of fetal growth: ponderal index, head circumference/ abdominal circumference ratio, cephalization index and birth weight/ placenta weight ratio was collected. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI). All measurements were evaluated as gestational age and sex specific z-scores and in z-score percentile groups, adjusted for potential confounders, and stratified on gestational age groups (<32, 32-36, 37-38, 39, 40, ≥ 41 weeks).

RESULTS

We identified 503,784 singleton births, of which 983 were confirmed cases of CP. Head/ abdominal circumference ratio (aHR:1.12; 95%CI:1.07-1.16) and cephalization index (aHR:1.14; 95%CI:1.11-1.16) were associated with the risk of CP irrespective of gestational age. Birth weight-placental weight ratio was also associated with CP in the entire cohort (aHR:0.90; 95%CI:0.83-0.97). Ponderal index had a u-shaped association with CP, where both children with low and high ponderal index were at higher risk of CP.

CONCLUSIONS

CP is associated with disproportions between birth weight, birth length, placental weight and head circumference suggesting pre and perinatal conditions contribute to fetal growth restriction in children with CP.

Maternal intake of fat in pregnancy and offspring metabolic health - A prospective study with 20 years of follow-up

BACKGROUND

Maternal fat intake during pregnancy in relation to offspring metabolic outcomes has been studied primarily in animal models, yet little is known about the association in humans. The aim of this study was to examine the association of total and subtype of fat consumption in pregnancy with anthropometric measures and biomarkers of adiposity and glucose metabolism in the offspring.

METHODS

A source population was 965 Danish pregnant women recruited in 1988-1989 with offspring follow-up at 20 years. Information on fat intake was collected in the 30(th) week of gestation, and we subdivided fat according to saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fat. Offspring body mass index (BMI) and waist circumference (WC) were recorded at follow-up (n = 670-678), and biomarkers were quantified in a subset (n = 443) of participants. Multivariable linear and log-binomial regression were used to calculate effect estimates and 95% CI for a 1:1%energy substitution of carbohydrates for fat.

RESULTS

The mean (standard deviation) BMI was 22.1 (3.3) and 22.8 (2.9) kg/m(2) in female and male offspring, respectively. The median (10th to 90th percentile) of maternal fat intake was 31% of energy [23,39]. We found no overall associations for maternal fat intake with female offspring anthropometry. However, for male offspring higher intake of MUFA during pregnancy was associated with higher insulin levels at 20 years (Q4 vs. Q1: %Δ: 37, 95% CI: 1, 86) accompanied by a non-significant 3.6 (95% CI: -1.1, 8.2) cm increase in WC. High maternal total fat intake (>=35% energy) was also associated with higher BMI (0.9, 95% CI: 0.2, 1.6) and WC (4.0, 95% CI: 1.6, 2.3) among male offspring.

CONCLUSIONS

A high fat diet during pregnancy may increase adiposity in adult male offspring. We surmise that maternal MUFA intake during this time included both MUFA and trans fat misclassified as MUFA, and that the associations observed may be more reflective of the latter exposure.

Maternal protein intake during pregnancy and offspring overweight 20 y later

BACKGROUND

Animal studies have shown that protein intake in pregnancy may influence offspring fat metabolism and adiposity. The macronutrient ratio in human pregnancy appears to be important for offspring glucose tolerance; however, less is known about the influence on offspring adiposity.

OBJECTIVE

We examined the relation between maternal dietary protein intake during pregnancy and offspring anthropometric measures and biomarkers of adiposity and glucose metabolism.

DESIGN

We used a prospective cohort of 965 Danish pregnant women recruited in 1988-1989 with offspring follow-up at 19-21 y. Macronutrient intake was collected in gestational week 30, and we divided protein according to its source (animal and vegetable including cereals). Offspring body mass index (BMI; in kg/m(2)) and waist circumference were recorded at follow-up (n = 695-697), and biomarkers were quantified in a subset (n = 443) of participants. We used multivariable linear and log-binomial regression to calculate effect estimates and 95% CIs for a 1:1-g substitution of carbohydrates for protein.

RESULTS

Offspring mean (±SD) BMI was 22.1 ± 3.3 and 22.8 ± 2.9 for women and men, respectively. The prevalence of overweight (BMI ≥25) was 16.9% for women and 19.1% for men. We showed that a 1:1-g substitution of animal protein for carbohydrates increased risk of BMI ≥25 in female [quartile 4 compared with quartile 1: risk ratio (RR): 3.36; 95% CI: 1.52, 7.42] and male (quartile 4 compared with quartile 1: RR: 2.22; 95% CI: 0.92, 5.35) offspring. These results appeared to be accounted for by protein from meat sources. The results could not be explained by postnatal risk factors.

CONCLUSIONS

Protein from animal sources, primarily meat products, consumed during pregnancy may increase risk of overweight in offspring; this association appeared to be stronger for female offspring. Because of the lack of information on postnatal exposure in this cohort, these results are hypothesis-generating and need to be replicated in other cohorts.

Fetal growth and cardio-metabolic risk factors in the 20-year-old offspring

OBJECTIVE

To investigate the association between prenatal growth patterns as estimated by biparietal diameter and cardio-metabolic risk at 20 years.

DESIGN

Follow-up study.

SETTING

Denmark 1988-2009.

POPULATION

Two cohorts of children born between 1988 and 1990 (n=707) and followed up in 2008-2009 (n=333-509).

METHODS

We have access to biparietal diameter from early ultrasound scan and birthweight. For each gender, biparietal diameter and birthweight, gestational age-specific growth-z-scores were calculated. A change in growth trajectory was depicted as a shift in z-score for the two growth measures. Multiple linear regression modeling was used to estimate associations between biparietal diameter and birthweight z-scores and later cardio-metabolic risk factors as well as estimating whether changing growth trajectory was associated with later cardio-metabolic risk.

MAIN OUTCOME MEASURES

Self-reported anthropometrics and clinically measured blood pressure, heart rate and biochemical measures associated with cardio-metabolic health.

RESULTS

After adjustments, biparietal diameter was not associated with any of the outcomes. Birthweight was positively associated with both adult height and weight and inversely associated with insulin, triglyceride and insulin resistance. Also, the data indicated a U-shaped association between growth in the second half of pregnancy and adult body mass index among individuals with a low biparietal diameter in mid-pregnancy.

CONCLUSION

Different patterns of intrauterine growth may be associated with later risk of cardio-metabolic disease.

Coffee and tea consumption, genotype-based CYP1A2 and NAT2 activity and colorectal cancer risk-results from the EPIC cohort study

Coffee and tea contain numerous antimutagenic and antioxidant components and high levels of caffeine that may protect against colorectal cancer (CRC). We investigated the association between coffee and tea consumption and CRC risk and studied potential effect modification by CYP1A2 and NAT2 genotypes, enzymes involved in the metabolization of caffeine. Data from 477,071 participants (70.2% female) of the European Investigation into Cancer and Nutrition (EPIC) cohort study were analyzed. At baseline (1992-2000) habitual (total, caffeinated and decaffeinated) coffee and tea consumption was assessed with dietary questionnaires. Cox proportional hazards models were used to estimate adjusted hazard ratio's (HR) and 95% confidence intervals (95% CI). Potential effect modification by genotype-based CYP1A2 and NAT2 activity was studied in a nested case-control set of 1,252 cases and 2,175 controls. After a median follow-up of 11.6 years, 4,234 participants developed CRC (mean age 64.7 ± 8.3 years). Total coffee consumption (high vs. non/low) was not associated with CRC risk (HR 1.06, 95% CI 0.95-1.18) or subsite cancers, and no significant associations were found for caffeinated (HR 1.10, 95% CI 0.97-1.26) and decaffeinated coffee (HR 0.96, 95% CI 0.84-1.11) and tea (HR 0.97, 95% CI 0.86-1.09). High coffee and tea consuming subjects with slow CYP1A2 or NAT2 activity had a similar CRC risk compared to non/low coffee and tea consuming subjects with a fast CYP1A2 or NAT2 activity, which suggests that caffeine metabolism does not affect the link between coffee and tea consumption and CRC risk. This study shows that coffee and tea consumption is not likely to be associated with overall CRC.

First trimester coffee and tea intake and risk of gestational diabetes mellitus: a study within a national birth cohort

OBJECTIVE

Coffee and tea consumption is associated with a decreased type 2 diabetes risk in non-pregnant adults. We examined the relation between first trimester coffee and tea consumption and gestational diabetes mellitus (GDM) risk.

DESIGN

Population-based cohort study.

SETTING

Denmark 1996-2002.

POPULATION

Non-diabetic women with singleton pregnancies in the Danish National Birth Cohort (n = 71,239).

METHODS

Estimated adjusted relative risks (RR) and 95% confidence intervals (95%CI) for the association between first trimester coffee and tea or estimated total caffeine and GDM.

MAIN OUTCOME MEASURES

GDM ascertained from the National Hospital Discharge Register or maternal interview.

RESULTS

Coffee or tea intake was reported in 81.2% (n = 57,882) and 1.3% (n = 912) of pregnancies were complicated by GDM. Among non-consumers, 1.5% of pregnancies were complicated by GDM. Among coffee drinkers, GDM was highest among women who drank ≥8 cups/day (1.8%) with no significant difference across intake levels (P = 0.10). Among tea drinkers, there was no difference in GDM across intake levels (1.2%; P = 0.98). After adjustment for age, socio-occupational status, parity, pre-pregnancy body mass index, smoking, and cola, there was suggestion of a protective, but non-significant association with increasing coffee (RR ≥8 versus 0 cups/day = 0.89 [95%CI 0.64-1.25]) and tea (RR ≥8 versus 0 cups/day = 0.77 [95%CI 0.55-1.08]). Results were similar by smoking status, except a non-significant 1.45-fold increased risk with ≥8 coffee cups/day for non-smokers. There was a non-significant reduced GDM risk with increasing total caffeine.

CONCLUSIONS

Our results suggest that moderate first trimester coffee and tea intake were not associated with GDM increased risk and possibly may have a protective effect.

Periconceptional intake of vitamins and fetal death: a cohort study on multivitamins and folate

BACKGROUND

Women planning to conceive are often advised to take multivitamins. Whether this affects the survival of the fetus is not known.

METHODS

We used data from 35 914 women in the Danish National Birth Cohort who at recruitment had reported the number of weeks of supplement use during a 12-week periconceptional period. A telephone interview provided information about maternal characteristics and data on fetal death came from registers. The associations between periconceptional multivitamin or folate-only use and early (<20 weeks) and late (≥20 weeks) fetal death were estimated by hazard ratios (HR) with 95% confidence intervals (CI). Follow-up started at 8 completed weeks of gestation, and comparisons were made with no supplement use at any time during the periconceptional period.

RESULTS

Any multivitamin use was associated with a small increased crude risk of fetal death [HR 1.12 (1.01-1.25)], which was restricted to early losses [HR 1.18 (1.05-1.33)] compared with late losses [HR 0.82 (0.62-1.10)]. Adjustment for maternal factors increased this excess risk further. Whereas regular users of multivitamins (4-6 weeks of 6) before conception had more early losses [HR 1.29 (1.12-1.48)], a decreased risk of late losses was indicated when use started after conception [HR 0.65 (0.39-1.09)]. Folate-only use was not associated with fetal death.

CONCLUSIONS

Multivitamin use was associated with a modest increased risk of early fetal death. For late fetal death, regular supplement use after conception may decrease risk, but numbers were small. Further studies on preconceptional multivitamin use are needed to guide public health recommendations.

Maternal concentrations of persistent organochlorine pollutants and the risk of asthma in offspring: results from a prospective cohort with 20 years of follow-up

BACKGROUND

Previous findings suggest that developmental exposures to persistent organochlorine pollutants (POPs) may be detrimental for the development of the immune system in the offspring. Whether these suspected immunoregulatory effects persist beyond early childhood remains unclear.

OBJECTIVES

The objective of this study was to evaluate the association between maternal serum concentrations of POPs and the risk of asthma in offspring after 20 years of follow-up.

METHODS

A birth cohort with 965 women was formed in 1988-1989 in Aarhus, Denmark. Concentrations of six polychlorinated biphenyls (PCBs) (congeners 118, 138, 153, 156, 170, 180), hexachlorobenzene (HCB), and dichlorodiphenyldichloroethylene (p,p´-DDE) were quantified in maternal serum (n=872) collected in gestation week 30. Information about offspring use of asthma medications was obtained from the Danish Registry of Medicinal Product Statistics.

RESULTS

Maternal serum concentrations of HCB and dioxin-like PCB-118 were positively associated with offspring asthma medication use after 20 years of follow-up (p for trend<0.05). Compared with subjects in the first tertile of maternal concentration, those in the third tertile of PCB-118 had an adjusted hazard ratio (HR) of 1.90 (95% CI: 1.12, 3.23). For HCB the HR for the third versus the first tertile of maternal concentration was 1.92 (95% CI: 1.15, 3.21). Weak positive associations were also estimated for PCB-156 and the non-dioxin-like PCBs (PCBs 138, 153, 170, 180). No associations were found for p,p´-DDE.

CONCLUSIONS

Maternal concentrations of PCB-118 and HCB were associated with increased risk of asthma in offspring followed through 20 years of age.

Maternal concentrations of persistent organochlorine pollutants and the risk of asthma in offspring: results from a prospective cohort with 20 years of follow-up

BACKGROUND

Previous findings suggest that developmental exposures to persistent organochlorine pollutants (POPs) may be detrimental for the development of the immune system in the offspring. Whether these suspected immunoregulatory effects persist beyond early childhood remains unclear.

OBJECTIVES

The objective of this study was to evaluate the association between maternal serum concentrations of POPs and the risk of asthma in offspring after 20 years of follow-up.

METHODS

A birth cohort with 965 women was formed in 1988-1989 in Aarhus, Denmark. Concentrations of six polychlorinated biphenyls (PCBs) (congeners 118, 138, 153, 156, 170, 180), hexachlorobenzene (HCB), and dichlorodiphenyldichloroethylene (p,p´-DDE) were quantified in maternal serum (n=872) collected in gestation week 30. Information about offspring use of asthma medications was obtained from the Danish Registry of Medicinal Product Statistics.

RESULTS

Maternal serum concentrations of HCB and dioxin-like PCB-118 were positively associated with offspring asthma medication use after 20 years of follow-up (p for trend<0.05). Compared with subjects in the first tertile of maternal concentration, those in the third tertile of PCB-118 had an adjusted hazard ratio (HR) of 1.90 (95% CI: 1.12, 3.23). For HCB the HR for the third versus the first tertile of maternal concentration was 1.92 (95% CI: 1.15, 3.21). Weak positive associations were also estimated for PCB-156 and the non-dioxin-like PCBs (PCBs 138, 153, 170, 180). No associations were found for p,p´-DDE.

CONCLUSIONS

Maternal concentrations of PCB-118 and HCB were associated with increased risk of asthma in offspring followed through 20 years of age.

Preschool behavioral problems in children prenatally exposed to antiepileptic drugs - a follow-up study

We studied the association between maternal epilepsy, antiepileptic drug (AED) treatment, and behavioral problems in preschool children. In the Danish National Birth Cohort, we identified 4- to 5-year-old children whose mothers had epilepsy and received AED treatment (n=133) or not (n=304) during pregnancy and compared them with randomly selected children whose mothers did not have epilepsy (n=1193). The children's behavioral problems were assessed by the use of the Strengths and Difficulties Questionnaire (SDQ). Children prenatally exposed to AEDs more often had an abnormal total SDQ score as compared with children of women without epilepsy (odds ratio (OR)=4.8 (95% CI: 1.9-12.1)) and as compared with children of women with epilepsy who were not treated with AEDs during their pregnancy (OR=4.0 (95% CI: 1.3-12.8)). In conclusion, prenatal AED exposure may increase the risk of behavioral problems in preschool children even after adjustments for potential confounders and maternal epilepsy.

Maternal infections during pregnancy and cerebral palsy: a population-based cohort study

BACKGROUND

Cerebral palsy (CP) is a common motor disability in childhood. We examined the association between maternal infections during pregnancy and the risk of congenital CP in the child.

METHODS

Liveborn singletons in Denmark between 1997 and 2003 were identified from the Danish National Birth Registry and followed from 1 year of life until 2008. Redemption of antibiotics from the National Register of Medicinal Product Statistics and maternal infections reported by the National Hospital Register were used as markers of maternal infection during pregnancy. CP diagnoses were obtained from the Danish Cerebral Palsy Registry. Adjusted hazard ratio (HR) and 95% confidence interval (CI) were estimated by Cox proportional hazard models.

RESULTS

Of the 440 564 singletons with follow-up data, 840 were diagnosed with congenital CP. Maternal genito-urinary tract infections (HR 2.1, 95% CI 1.4, 3.2) were associated with CP in all births, in term births (HR 1.9, 95% CI 1.1, 3.2), in children with spastic CP (HR 2.1, 95% CI 1.4, 3.3), and among first-born children (HR 1.9, 95% CI 1.4, 3.3). Overall, we found associations between redeemed nitrofurantoin (HR 1.7, 95% CI 1.1, 2.8) and CP. Among trimester-specific exposures, CP risk was associated with prescriptions redeemed in the first trimester for any antibacterials, beta-lactam antibacterials, and nitrofurantoin, an antibiotic commonly used to treat lower urinary tract infection, and genito-urinary tract infections in the third trimester.

CONCLUSION

Genito-urinary tract infections and antibiotic use during pregnancy were associated with increased risks of CP, indicating that some maternal infections or causes of maternal infections present in prenatal life may be part of a causal pathway leading to CP.

Congenital cerebral palsy and prenatal exposure to self-reported maternal infections, fever, or smoking

OBJECTIVE

The objective of the study was to investigate the association between maternal self-reported infections, fever, and smoking in the prenatal period and the subsequent risk for congenital cerebral palsy (CP).

STUDY DESIGN

We included the 81,066 mothers of singletons born between 1996 and 2003 who participated in the Danish National Birth Cohort. Children were followed up through December 2008. Information on maternal infections, fever, smoking, and other demographic and lifestyle factors during pregnancy were reported by mothers in computer-assisted telephone interviews in early and midgestation. We identified 139 CP cases including 121 cases of spastic CP (sCP) as confirmed by the Danish National Cerebral Palsy Register. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Self-reported vaginal infections were associated with an increased risk of CP and sCP (aHR, 1.52; 95% CI, 1.04-2.24; and aHR, 1.73; 95% CI, 1.16-2.60, respectively) and particularly untreated vaginal infections were associated with an increased risk of sCP (aHR, 1.95; 95% CI, 1.16-3.26). Fever was associated with the risk of CP (aHR, 1.53; 95% CI, 1.06-2.21). Smoking 10 or more cigarettes per day during pregnancy was also associated with sCP (aHR, 1.80; 95% CI, 1.10-2.94). There was a modest excess in risk for children exposed to both heavy smoking and vaginal infections. No other self-reported infections were significantly associated with CP.

CONCLUSION

Self-reported vaginal infections, fever, and smoking 10 or more cigarettes per day during pregnancy were associated with a higher risk of overall CP and/or sCP.

Prenatal antidepressant exposure and behavioral problems in early childhood--a cohort study

OBJECTIVE

To estimate a potential association between in utero exposure to antidepressants and behavioral problems in childhood.

METHOD

Information on exposures was obtained from the Danish National Birth Cohort. We studied the children of 127 mothers who had used antidepressants during pregnancy and compared these to 98 children of mothers with a prenatal depression with no use of antidepressants during pregnancy and 723 children of mothers with no prenatal depression and no use of antidepressant during pregnancy (unexposed). Behavioral problems were assessed at 4 or 5 years of age by the parent-reported Strengths and Difficulties Questionnaire (SDQ).

RESULTS

Prenatal antidepressant exposure was not associated with abnormal SDQ scores compared with prenatal exposure to untreated prenatal depression or to no exposure. Untreated prenatal depression was associated with abnormal SDQ scores in the subscales of conduct [adjusted odds ratio (aOR) 2.3 (95% CI, 1.2-4.5)] and prosocial problems [aOR 3.0 (95% CI, 1.2-7.8)] compared with unexposed children. Total SDQ score was higher in children of mothers with untreated prenatal depression. These associations attenuated after adjusting for postnatal maternal psychiatric disease.

CONCLUSION

Prenatal antidepressant exposure was not associated with behavioral or emotional problems in early childhood.

Spontaneous abortion and a diet drug containing caffeine and ephedrine: a study within the Danish national birth cohort

Background

Medications may be consumed periconceptionally before a woman knows she is pregnant. In this study, the authors evaluate the association of a prescription diet drug (Letigen) containing ephedrine (20 mg) and caffeine (200 mg) with spontaneous abortion (SAB) in the Danish National Birth Cohort.

Methods

Women were recruited during their first prenatal visit from 1996–2002. Pre-conception and early pregnancy medication use was reported on the enrollment form, and pregnancy outcome was determined by linking the mother's Civil Registration Number to the Medical Birth Registry and the National Hospital Discharge Register. Of 97,903 eligible pregnancies, 4,443 ended in SAB between 5 and 20 completed gestational weeks, inclusive. Letigen use was reported for 565 pregnancies. Cox regression models accounting for left truncation were fit to estimate the effect of pre-conception and early pregnancy Letigen use on SAB.

Principal Findings

The estimated maternal age-adjusted hazard ratio for SAB was 1.1 (95% confidence interval 0.8–1.6) for any periconceptional Letigen use compared to no periconceptional use.

Conclusions

Although Letigen has high levels of caffeine (the recommended 3 pills/day are approximately equivalent to caffeine from 6 cups of coffee), periconceptional use does not appear to be associated with an appreciably increased hazard of clinically recognized SAB.

Prospective study evaluating performance of first-trimester combined screening for trisomy 21 using repeat sampling of maternal serum markers PAPP-A and free β-hCG

OBJECTIVE

To prospectively evaluate the performance of first-trimester combined screening for trisomy 21 using the biochemical markers pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotropin (free β-hCG) obtained before and at the time of the nuchal translucency (NT) scan.

METHODS

Three fetal medicine departments in Denmark participated in the study. Screening for trisomy 21 was set up as a two-step approach with blood sampling performed before the NT scan (early sample) and again at the time of the NT scan (late sample). PAPP-A and free β-hCG were measured on both the early and late samples. Age-standardized detection and false-positive rates for different screening protocols were calculated.

RESULTS

We collected two blood samples in 27 pregnancies affected by trisomy 21 and in 3891 control pregnancies. The early samples were taken between gestational ages 8 + 0 and 13 + 6 weeks, and the late samples between 11 + 3 and 14 + 6 weeks. The median interval between the samples was 17 (range, 1-40) days. We found a significantly better estimated screening performance when using early sampling vs late sampling (P < 0.05). With a risk cut-off of 1 in 100, at the time of the risk assessment the estimated detection and false-positive rates when using the early sample were 91% (95% CI, 81-98%) and 1.6% (95% CI, 1.3-2.0%), respectively. For fixed false-positive rates the highest detection rates were achieved using both blood samples. When comparing early sampling vs double sampling there was no significant difference in screening performance.

CONCLUSION

In combined first-trimester screening for trisomy 21, use of early sampling with measurement of PAPP-A and free β-hCG before the time of the NT scan can optimize screening performance. Using maternal serum markers obtained both before and at the time of the NT scan has the potential to further improve performance, but larger studies are needed to confirm this potential.

Long-term health outcomes in children born to mothers with diabetes: a population-based cohort study

BACKGROUND

To examine whether prenatal exposure to parental type 1 diabetes, type 2 diabetes, or gestational diabetes is associated with an increased risk of malignant neoplasm or diseases of the circulatory system in the offspring.

METHODS/PRINCIPAL FINDINGS

We conducted a population-based cohort study of 1,781,576 singletons born in Denmark from 1977 to 2008. Children were followed for up to 30 years from the day of birth until the onset of the outcomes under study, death, emigration, or December 31, 2009, whichever came first. We used Cox proportional hazards model to estimate hazard ratios (HR) with 95% confidence intervals (95% CI) for the outcomes under study while adjusting for potential confounders. An increased risk of malignant neoplasm was found in children prenatally exposed to maternal type 2 diabetes (HR = 2.2, 95%CI: 1.5-3.2). An increased risk of diseases of the circulatory system was found in children exposed to maternal type 1 diabetes (HR = 2.2, 95%CI: 1.6-3.0), type 2 diabetes (HR = 1.4, 95%CI: 1.1-1.7), and gestational diabetes (HR = 1.3, 95%CI: 1.1-1.6), but results were attenuated after excluding children with congenital malformations. An increased risk of diseases of the circulatory system was also found in children exposed to paternal type 2 diabetes (HR = 1.5, 95%CI: 1.1-2.2) and the elevated risk remained after excluding children with congenital malformations.

CONCLUSIONS

This study suggests that susceptibility to malignant neoplasm is modified partly by fetal programming. Diseases of the circulatory system may be modified by genetic factors, other time-stable family factors, or fetal programming.

Infertility, infertility treatment and behavioural problems in the offspring

Behavioural patterns in children of infertile couples may be influenced by both the underlying causes of infertility and stress in the couples. Treatment procedures, such as culture media and manipulation of gametes and embryos, may also result in developmental problems. We examined behavioural problems in children as a function of infertility and infertility treatment, using data from three population-based birth cohorts in Denmark (Aalborg-Odense Birth Cohort, Aarhus Birth Cohort and Danish National Birth Cohort). Information on time to pregnancy and infertility treatment was collected during pregnancy. Children aged between 7 and 21 years were assessed using the Strengths and Difficulties Questionnaire (SDQ). The SDQ was completed by mothers in all cohorts and, in addition, by teachers in the Aarhus cohort and by children themselves in the Aalborg-Odense cohort. Children born after a time to pregnancy of >12 months and no infertility treatment had a behavioural pattern similar to children of fertile parents. Teachers reported a higher total difficulties score for children born after infertility treatment, but no significant differences were seen on any subscales of the teachers' report, and neither the mothers nor the children reported any differences on the total difficulties score and the prosocial behaviour score. Our results are thus overall reassuring regarding behavioural problems in children born to infertile couples, regardless of infertility treatment.

Intake of fish oil during pregnancy and adiposity in 19-y-old offspring: follow-up on a randomized controlled trial

BACKGROUND

It is well established that obesity tends to track from early childhood into adult life. Studies in experimental animals have suggested that changes in the peri- and early postnatal intake of n-3 (omega-3) polyunsaturated acids can affect the development of obesity in adult life.

OBJECTIVE

The aim of the current study was to investigate the effect of daily supplementation with 2.7 g long-chain n-3 fatty acids during the third trimester of pregnancy on adiposity in 19-y-old offspring.

DESIGN

The study was based on follow-up of a randomized controlled trial from 1990, in which 533 pregnant women were randomly assigned to receive fish oil, olive oil, or no oil. At ≈19 y of age, the offspring of subjects from the randomized controlled trial were invited to undergo a physical examination, including anthropometric measurements and fasting blood sampling. The blood sample was analyzed for insulin, glucose, glycated hemoglobin, leptin, adiponectin, insulin-like growth factor I, and high-sensitivity C-reactive protein. Multiple linear regression modeling, adjusted for sex, smoking, and parental overweight, was used to estimate the effect of fish oil relative to that of olive oil on BMI (in kg/m(2)), waist circumference, and biochemical measures.

RESULTS

A total of 243 of the offspring were followed up. We found no difference between the fish-oil and olive oil groups in BMI (0.13; -0.92, 1.17) or waist circumference (0.7 cm; -2.1, 3.4 cm). Overall, results of the biochemical analyses supported the finding of no difference between the groups.

CONCLUSION

We detected no effect of fish-oil supplementation during pregnancy on offspring adiposity in adolescence.

Fish oil supplementation during late pregnancy does not influence plasma lipids or lipoprotein levels in young adult offspring

Nutritional influences on cardiovascular disease operate throughout life. Studies in both experimental animals and humans have suggested that changes in the peri- and early post-natal nutrition can affect the development of the various components of the metabolic syndrome in adult life. This has lead to the hypothesis that n-3 fatty acid supplementation in pregnancy may have a beneficial effect on lipid profile in the offspring. The aim of the present study was to investigate the effect of supplementation with n-3 fatty acids during the third trimester of pregnancy on lipids and lipoproteins in the 19-year-old offspring. The study was based on the follow-up of a randomized controlled trial from 1990 where 533 pregnant women were randomized to fish oil (n = 266), olive oil (n = 136) or no oil (n = 131). In 2009, the offspring were invited to a physical examination including blood sampling. A total of 243 of the offspring participated. Lipid values did not differ between the fish oil and olive oil groups. The relative adjusted difference (95% confidence intervals) in lipid concentrations was -3% (-11; 7) for LDL cholesterol, 3% (-3; 10) for HDL cholesterol, -1% (-6; 5) for total cholesterol,-4% (-16; 10) for TAG concentrations, 2%(-2; 7) for apolipoprotein A1, -1% (-9; 7) for apolipoprotein B and 3% (-7; 15) in relative abundance of small dense LDL. In conclusion, there was no effect of fish oil supplementation during the third trimester of pregnancy on offspring plasma lipids and lipoproteins in adolescence.

Diseases in children born to mothers with preeclampsia: a population-based sibling cohort study

OBJECTIVE

We previously reported associations between preeclampsia and the occurrence of metabolic and respiratory diseases in the offspring. In this article we examine whether the associations were due to preeclampsia or factors leading to preeclampsia.

STUDY DESIGN

From 1978 through 2004, we identified 22,264 discordant sib-pairs in Denmark according to prenatal exposure to preeclampsia. Exposed children were compared to their unexposed siblings by using stratified Cox regression to estimate hazard ratios and 95% confidence intervals for metabolic and respiratory diseases.

RESULTS

Exposed children had rather similar risks for metabolic disorders compared to their unexposed siblings. However, when the second child within each sib-pair was exposed, this child had an increased risk for respiratory diseases (hazard ratio, 1.55; 95% confidence interval, 1.20-2.01).

CONCLUSION

Factors leading to preeclampsia may shape susceptibility to metabolic or respiratory diseases in the offspring but a programming effect on respiratory diseases induced by preeclampsia cannot be ruled out.

Semen quality according to prenatal coffee and present caffeine exposure: two decades of follow-up of a pregnancy cohort

BACKGROUND

A few studies have investigated the association between male caffeine consumption in adult life and semen quality with conflicting results, but so far no studies have explored the effect of prenatal coffee exposure. We studied the association between prenatal coffee and current caffeine exposure and semen quality and levels of reproductive hormones.

METHODS

From a Danish pregnancy cohort established in 1984-1987, 347 sons out of 5109 were selected for a follow-up study conducted 2005-2006. Semen and blood samples were analyzed for conventional semen characteristics and reproductive hormones and were related to information on maternal coffee consumption during pregnancy and present caffeine consumption. Data were available for 343 men.

RESULTS

There was a tendency toward decreasing crude median semen volume (P = 0.06) and adjusted mean testosterone (P = 0.06) and inhibin B (P = 0.09) concentrations with increasing maternal coffee consumption during pregnancy. Sons of mothers drinking 4-7 cups/day had lower testosterone levels than sons of mothers drinking 0-3 cups/day (P = 0.04). Current male caffeine intake was associated with increasing testosterone levels (P = 0.007). Men with a high caffeine intake had approximately 14% higher concentration of testosterone than those with a low caffeine intake (P = 0.008).

CONCLUSIONS

The results observed in this study are only tentative, but they do not exclude a small to moderate effect of prenatal coffee exposure on semen volume and levels of reproductive hormones. Present adult caffeine intake did not show any clear associations with semen quality, but high caffeine intake was associated with a higher testosterone concentration.