Do pregnant women report use of dispensed medications?

Postmenopausal hormone therapy and cognition in twins

OBJECTIVE

Mild cognitive impairment may be caused by pathophysiological changes occurring decades prior to symptom development. It has been hypothesised that oestrogen can prevent such changes. We aimed to investigate the association between postmenopausal hormone therapy and cognition in Danish female twins and to examine differences in this association before and after publication of the findings from the Women's Health Initiative study in 2002.

STUDY DESIGN

This study includes cognitive assessment of 4510 twins aged 50+ years. Information on hormone therapy was obtained through Danish health registries. The association between current hormone therapy use and cognition was analysed in twins aged 50+ using both cross-sectional, intrapair and longitudinal analysis, adjusting for age, education, social class, and unobserved familial confounding.

RESULTS

Cross-sectionally, systemic HT users aged 70+ had a significantly lower cognitive function than non-users, whereas systemic HT users aged 50-69 did not differ from non-users before 2002. Longitudinal data in younger twins aged 50-69 showed a significantly lower cognitive function in systemic HT users after 2002 compared to non-users. Systemic HT users aged 70+ showed that the lower cognitive function was most explicit before 2002, whereas after 2002 the cognitive function was closer to non-users. Twins aged 50-69 who changed from systemic HT to local HT after 2002, or dropped it altogether, performed cognitively better.

CONCLUSIONS

Our findings cautiously indicate a change in the association between cognition and hormone therapy use after 2002, which suggests an alteration in the hormone therapy user profile in the wake of the 2002 WHI publication.

Prescribing patterns for higher dose folic acid in pregnant women with epilepsy treated with antiseizure medication

OBJECTIVE

This study was undertaken to characterize the use of higher doses of folic acid (≥1 mg daily) in relation to pregnancy in Denmark, Norway, and Sweden in women with epilepsy treated with antiseizure medication (ASM).

METHODS

In this observational study, we used data from national medical birth, patient, and prescription registers in Denmark, Norway, and Sweden to retrospectively identify pregnancies in women with epilepsy treated with ASM from 2006 to 2017. The proportion of higher dose folic acid supplementation in pregnancies among women receiving ASM for epilepsy was calculated according to country of origin, time period, and type of ASM. Logistic regression with restricted cubic splines was used to model country-specific time trends.

RESULTS

Among a total of 2 748 882 pregnancies, we identified 8695 (.3%) pregnancies after restricting the population to women with ASM-treated epilepsy. A prescription for higher dose folic acid was filled in 4719 (54.3%) of these pregnancies. The proportion supplemented with higher dose folic acid was highest in Sweden (74.3%) and lower in Norway (41.4%) and Denmark (34.3%). Furthermore, we observed a decreasing trend of higher dose folic acid use in Denmark and Norway from year 2012 to 2017. Among those who used higher dose folic acid, 42% did not start preconception supplementation with higher dose folic acid.

SIGNIFICANCE

Supplementation with higher dose folic acid occurred in approximately half of pregnancies in women with ASM-treated epilepsy, with many not starting supplementation until after becoming pregnant. Considerable variability was observed in the use of higher dose folic acid across the countries, despite similar population characteristics and health care systems. Future guidelines should be simplified with clear recommendations developed in a collaborative manner by relevant specialists including neurologists, obstetricians, pediatricians, and public health specialists to enhance real-world applicability.

Correlation of drug dose estimated from national prescription registers with mean blood level of antiseizure medication in pregnancy

PURPOSE

The purpose was to examine the correlation of antiseizure medication drug dose estimated from prescription fill records from prescription registers with blood levels during pregnancy.

METHODS

We conducted a Nation-wide study of mothers who gave birth in Denmark between 1 January 2014 and 31 December 2018 using data from Danish Prescription and Laboratory Registers. We identified mothers with blood level measurements of antiseizure medication. The main exposure was estimated antiseizure medication dosage estimated from pregnancy-filled prescriptions in the Danish Prescription Register. The main outcome was the correlation of estimated dose with mean blood level of antiseizure medication in pregnancy. For privacy reasons, the number of blood level measurement and prescription fills were rounded to nearest 10, but proportions reported as exact values.

RESULTS

Among 298 560 pregnancies, we identified pregnancies with recorded prescription fill from the prescription register for valproate (N = 90), lamotrigine (N = 1360), levetiracetam (N = 340), topiramate (N = 100), and carbamazepine (N = 60). In these pregnancies, blood level measurements were available in 50 (53%) pregnancies for valproate, 850 (62%) pregnancies for lamotrigine, 320 (93%) pregnancies for levetiracetam, 50 (68%) pregnancies for carbamazepine, and 40 (35%) pregnancies for topiramate. Pearsons's correlation coefficients for the correlation of estimated antiseizure medication dose with mean blood levels were 0.67 (p < 0.0001) for valproate, 0.63 (p < 0.0001) for lamotrigine, 0.63 (p < 0.0001) for levetiracetam, 0.76 (<0.0001) for carbamazepine and 0.89 (<0.0001) for topiramate.

CONCLUSIONS

Dose of antiseizure medication estimated from prescription fills was a good proxy for blood levels and thus for biological exposure in pregnancy, suggesting that administrative prescription fill records may be a valuable resource for estimating exposure to antiseizure medication in pregnancy.

Prenatal exposure to antiseizure medications and fetal growth: a population-based cohort study from the Nordic countries

Background

The short- and long-term consequences of restricted fetal growth cause considerable concern, and how prenatal exposure to different antiseizure medications (ASMs) affects fetal growth remains uncertain.

Methods

This was a population-based cohort study of liveborn singleton children born in Denmark, Finland, Iceland, Norway, and Sweden from 1996 to 2017. Prenatal exposure was defined as maternal filling of prescriptions for ASM during pregnancy registered in national prescription registries and primary outcomes were adjusted odds ratios (aORs) of microcephaly or being born small for gestational age.

Findings

We identified 4,494,918 children (males: 51.3%, 2,306,991/4,494,918), including 38,714 (0.9%) children of mothers with epilepsy. In the overall population, prenatal monotherapy exposure with carbamazepine (aOR: 1.25 (95% CI: 1.12-1.40)), pregabalin (aOR: 1.16 (95% CI: 1.02-1.31)), oxcarbazepine (aOR: 1.48 (95% CI: 1.28-1.71)), clonazepam (aOR: 1.27 (95% CI: 1.10-1.48)), and topiramate (aOR: 1.48 (95% CI: 1.18-1.85)) was associated with risk of being born small for gestational age, and carbamazepine was associated with microcephaly (aOR: 1.43 (95% CI: 1.17-1.75)). In children of mothers with epilepsy, prenatal exposure to carbamazepine (aOR: 1.27 (95% CI: 1.11-1.47)), oxcarbazepine (aOR: 1.42 (95% CI: 1.18-1.70)), clonazepam (aOR: 1.40 (95% CI: 1.03-1.89)), and topiramate (aOR: 1.86 (95% CI: 1.36-2.54)) was associated with being born small for gestational age; carbamazepine, with microcephaly (aOR: 1.51 (95% CI: 1.17-1.95)). No associations with small for gestational age and microcephaly were identified after prenatal exposure to lamotrigine, valproate, gabapentin, levetiracetam, phenobarbital, acetazolamide, phenytoin, clobazam, primidone, zonisamide, vigabatrin, ethosuximide and lacosamide, but except for lamotrigine, valproate, gabapentin, and levetiracetam, numbers of exposed children were small.

Interpretation

Prenatal exposure to carbamazepine, oxcarbazepine, clonazepam, and topiramate was associated with increased risk of being born small for gestational age in both the overall population and in children of women with epilepsy suggesting that prenatal exposure to these drugs is associated with fetal growth restriction.

Funding

The NordForsk Nordic Program on Health and Welfare (83539), the Independent Research Fund Denmark (1133-00026B), the Danish Epilepsy Association, the Central Denmark Region, the Novo Nordisk Foundation (NNF16OC0019126 and NNF22OC0075033), and the Lundbeck Foundation (R400-2022-1205).

Prenatal Exposure to Antiseizure Medications and Risk of Epilepsy in Children of Mothers With Epilepsy

Importance

Use of valproate and certain other antiseizure medications (ASMs) in pregnancy is associated with abnormal fetal brain development with potential long-term implications for the child.

Objective

To examine whether use of valproate and other ASMs in pregnancy among mothers with epilepsy is associated with epilepsy risk in their children.

Design, Setting, and Participants

This prospective, population-based register cohort study included singletons born to mothers with epilepsy in Denmark, Finland, Iceland, Norway, and Sweden from January 1, 1996, to December 31, 2017. Data analysis was performed from October 2022 to December 2023.

Exposure

Redeemed prescription for an ASM from 30 days before pregnancy until birth.

Main Outcomes and Measures

The main outcome was epilepsy in children, assessed using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnoses from hospital care. Adjusted hazard ratios (AHRs) and 95% CIs were estimated using Cox proportional hazards regression. Secondary analyses included dose-response analyses, analyses using children of mothers who discontinued ASM prior to pregnancy as the reference, and sibling analyses.

Results

This cohort study included 38 663 children of mothers with epilepsy (19 854 [51.4%] boys). Children were followed up from birth; the mean length of follow-up was 7.2 years (range 0-22 years). Compared with 22 207 children of mothers not using an ASM in pregnancy, increased risks of epilepsy in children of mothers who used valproate in pregnancy (monotherapy: AHR, 2.18; 95% CI, 1.70-2.79; polytherapy: AHR, 2.10; 95% CI, 1.49-2.96) were observed. However, there was no dose-dependent association, and there was a similar risk of epilepsy in siblings who were exposed and unexposed to valproate (AHR, 0.95; 95% CI, 0.50-1.82). Prenatal exposure to topiramate monotherapy was associated with increased risk of epilepsy (AHR, 2.32; 95% CI, 1.30-4.16), and the risk was greater for higher doses, but the risk attenuated in comparisons with children of mothers who discontinued topiramate before pregnancy (AHR, 1.19; 95% CI, 0.26-5.44). Prenatal exposure to clonazepam monotherapy was also associated with increased epilepsy risk (AHR, 1.90; 95% CI, 1.16-3.12), but limited follow-up and low numbers precluded further analyses. No associations were observed for prenatal exposure to lamotrigine (AHR, 1.18; 95% CI, 0.95-1.47), levetiracetam (AHR, 1.28; 95% CI, 0.77-2.14), carbamazepine (AHR, 1.13; 95% CI, 0.85-1.50), or oxcarbazepine (AHR, 0.68; 95% CI, 0.44-1.05).

Conclusions and Relevance

In this cohort study of children born to mothers with epilepsy, the associations found between prenatal exposure to certain ASMs and the child's risk of epilepsy did not persist in sensitivity analyses, suggesting that maternal ASM use in pregnancy may not increase epilepsy risk in children beyond that associated with the maternal epilepsy itself. These findings are reassuring for women in need of treatment with ASM in pregnancy.

The association between bacteriuria and adverse pregnancy outcomes: a systematic review and meta-analysis of observational studies

BACKGROUND

Antibiotics for bacteriuria and urinary tract infection are commonly prescribed during pregnancy to avoid adverse pregnancy outcomes. The aim of this study was to evaluate the association between significant bacteriuria in pregnancy and any of the four pregnancy outcomes: preterm delivery; low birth weight; small for gestational age; and preterm labour.

METHODS

Systematic review with meta-analysis of observational studies. We searched PubMed, EMBASE, the Cochrane CENTRAL library, and Web of Science for observational studies published before 1 March 2022. The risk of bias was assessed using the Newcastle-Ottawa scale. Study identification, data extraction and risk-of-bias assessment was performed by two independent authors. We combined the included studies in meta-analyses and expressed results as ORs with 95% CIs (Prospero CRD42016053485).

RESULTS

We identified 58 studies involving 421 657 women. The quality of the studies was mainly poor or fair. The pooled, unadjusted OR for the association between any significant bacteriuria and: (i) preterm delivery was 1.62 (95% CI: 1.30-2.01; 27 studies; I2 = 61%); (ii) low birth weight was 1.50 (95% CI: 1.30-1.72; 47 studies; I2 = 74%); (iii) preterm labour was 2.29 (95% CI: 1.53-3.43; 3 studies; I2 = 0%); and (iv) small for gestational age was 1.33 (95% CI: 0.88-2.02; 7 studies; I2 = 54%). Four studies provided an adjusted OR, but were too diverse to combine in meta-analysis.

CONCLUSIONS

This systematic review identified an association between significant bacteriuria in pregnancy and the three complications: preterm delivery; low birth weight; and preterm labour. However, the quality of the available evidence is insufficient to conclude whether this association is merely due to confounding factors. There is a lack of high-quality evidence to support active identification and treatment of bacteriuria in pregnancy.

Cranberry Supplements for Urinary Tract Infection Prophylaxis in Pregnant Women: A Systematic Review of Clinical Trials and Observational Studies on Efficacy, Acceptability, Outcomes Measurement Methods, and Studies' Feasibility

Cranberry supplements are commonly used to prevent urinary tract infections (UTIs). However, their usefulness is uncertain in pregnant women. We aimed to comprehensively summarize the current knowledge on cranberry supplements' efficacy and acceptability during pregnancy in addition to the outcomes measurement methods and studies' feasibility. To achieve it, we searched PubMed, PMC, and Europe PMC databases plus screened citations followed by critical appraisal of included eligible English-written primary studies that (1) focused on pregnant women supplemented with any cranberry supplements; (2) provided data on cranberry supplements' efficacy, acceptability, outcomes measurement methods, and studies' feasibility; (3) included human subjects; and (4) published worldwide. Two randomized clinical trials (RCTs) and one nested cohort study, including 1156 pregnant women in total, contributed to our analysis. A tendency toward UTI reduction was demonstrated, although the results' validity was impacted by significant juice-induced gastrointestinal intolerance (23%; 44 of 188 subjects). Changing the form of supplementation from cranberry juice to capsules reduced the issue, causing side effects in one of 49 subjects (2%). Nevertheless, both RCTs still experienced significant recruitment and retention problems, which were at 33% and 59% on average, respectively. Newly acquired safety data on 919 more subjects suggests no increased risks of all malformations, vaginal bleeding, and neonatal complications. Investigating cranberry capsules' efficacy as a non-antibacterial option for UTI prevention in pregnant women has become a feasible and important direction with the current advancement in understanding cranberry supplements' actions, recommended doses plus regimens, and their safety in the population. We reviewed the challenges and discovered knowledge gaps and the implementation strategies for future studies.

High-dose folic acid and cancer risk; unjustified concerns by von Wrede and colleagues regarding our paper

Women using antiseizure medication in pregnancy are often advised to use high doses of folic acid supplements (1mg to 5 mg) to reduce the risk of teratogenicity. Recently, we published a report showing an association between maternal prescription fill of high dose folic acid in relation to pregnancy and childhood cancer in the offspring. The report has sparked a debate about which dose of folic acid that should be recommended in pregnancy in women in need of antiseizure medication. In this Commentary, we explain our findings and the method used in our report, and answer recent questions that have emerged.

Maternal infections and medications in pregnancy: how does self-report compare to medical records in childhood cancer case-control studies?

BACKGROUND

Studies examining the potential impact of mothers' health during pregnancy on the health of their offspring often rely on self-reported information gathered several years later. To assess the validity of this approach, we analysed data from a national case-control study of childhood cancer (diagnosed <15 years) that collected health information from both interviews and medical records.

METHODS

Mothers' interview reports of infections and medications in pregnancy were compared with primary care records. Taking clinical diagnoses and prescriptions as the reference, sensitivity and specificity of maternal recall along with kappa coefficients of agreement were calculated. Differences in the odd ratios estimated using logistic regression for each information source were assessed using the proportional change in the odds ratio (OR).

RESULTS

Mothers of 1624 cases and 2524 controls were interviewed ∼6 years (range 0-18 years) after their child's birth. Most drugs and infections were underreported; in general practitioner records, antibiotic prescriptions were nearly three times higher and infections >40% higher. Decreasing with increasing time since pregnancy, sensitivity was ⩽40% for most infections and all drugs except 'anti-epileptics and barbiturates' (sensitivity 80% among controls). ORs associated with individual drug/disease categories that were based on self-reported data varied from 26% lower to 26% higher than those based on medical records; reporting differences between mothers of cases and controls were not systematically in the same direction.

CONCLUSIONS

The findings highlight the scale of under-reporting and poor validity of questionnaire-based studies conducted several years after pregnancy. Future research using prospectively collected data should be encouraged to minimize measurement errors.

Prenatal Exposure to Antiseizure Medication and Incidence of Childhood- and Adolescence-Onset Psychiatric Disorders

Importance

Prenatal antiseizure medication (ASM) exposure has been associated with adverse early neurodevelopment, but associations with a wider range of psychiatric end points have not been studied.

Objective

To examine the association between prenatal exposure to ASM with a spectrum of psychiatric disorders in childhood and adolescence in children of mothers with epilepsy.

Design, Setting, and Participants

This prospective, population-based register study assessed 4 546 605 singleton children born alive in Denmark, Finland, Iceland, Norway, and Sweden from January 1, 1996, to December 31, 2017. Of the 4 546 605 children, 54 953 with chromosomal disorders or uncertain birth characteristics were excluded, and 38 661 children of mothers with epilepsy were identified. Data analysis was performed from August 2021 to January 2023.

Exposures

Prenatal exposure to ASM was defined as maternal prescription fills from 30 days before the first day of the last menstrual period until birth.

Main Outcomes and Measures

The main outcome measure was diagnosis of psychiatric disorders (a combined end point and 13 individual disorders). Estimated adjusted hazard ratios (aHRs) using Cox proportional hazards regression and cumulative incidences with 95% CIs are reported.

Results

Among the 38 661 children of mothers with epilepsy (16 458 [42.6%] exposed to ASM; 19 582 [51.3%] male; mean [SD] age at the end of study, 7.5 [4.6] years), prenatal valproate exposure was associated with an increased risk of the combined psychiatric end point (aHR, 1.80 [95% CI, 1.60-2.03]; cumulative risk at 18 years in ASM-exposed children, 42.1% [95% CI, 38.2%-45.8%]; cumulative risk at 18 years in unexposed children, 31.3% [95% CI, 28.9%-33.6%]), which was driven mainly by disorders within the neurodevelopmental spectrum. Prenatal exposure to lamotrigine, carbamazepine, and oxcarbazepine was not associated with an increased risk of psychiatric disorders, whereas associations were found for prenatal exposure to topiramate with attention-deficit/hyperactivity disorder (aHR, 2.38; 95% CI, 1.40-4.06) and exposure to levetiracetam with anxiety (aHR, 2.17; 95% CI, 1.26-3.72) and attention-deficit/hyperactivity disorder (aHR, 1.78; 95% CI, 1.03-3.07).

Conclusions and Relevance

Findings from this explorative study strengthen the evidence for the warning against the use of valproate in pregnancy and raise concern of risks of specific psychiatric disorders associated with topiramate and levetiracetam. This study provides reassuring evidence that lamotrigine, carbamazepine, and oxcarbazepine are not associated with long-term behavioral or developmental disorders but cannot rule out risks with higher doses.

Low-Dose Aspirin after ASPRE-More Questions Than Answers? Current International Approach after PE Screening in the First Trimester

Preeclampsia (PE) is a multi-factorial disorder of pregnancy, and it continues to be one of the leading causes of fetal and maternal morbidity and mortality worldwide. Aspirin is universally recommended for high-risk women to reduce preeclampsia risk. The purpose of this review is to summarize the recommendations of various scientific societies on predicting preeclampsia and their indications for the inclusion of acetylsalicylic acid (ASA) prophylaxis. Fourteen guidelines were compared. The recommended dose, screening method, and gestational age at the start of the test vary depending on the recommendation. The societies are inclined to recommend using increasingly higher doses (>75 mg) of ASA, with many encouraging doses from 100 mg upward. Most societies indicate that the optimal time for implementing aspirin is prior to 16 weeks' gestation. Following the publication of the Aspirin for Evidence-Based Preeclampsia Prevention (ASPRE) trial results and other papers evaluating the Fetal Medicine Foundation (FMF) screening model, a large number of societies have changed their recommendations from those based on risk factors alone to the ones based on the risk assessment proposed by the FMF. This allows for the detection of a high-risk pregnancy population in whom aspirin will be remarkably effective in preventing preterm PE, thereby decreasing maternal and fetal morbidity.

Psychiatric visits during the postpartum year in women with eating disorders who continue or discontinue antidepressant treatment in pregnancy

OBJECTIVE

To determine the association between continued antidepressant use in pregnancy and postpartum psychiatric visits for eating (ED) or mood/anxiety disorders in women with preexisting ED.

METHOD

Using Danish health registry data (1998-2015), we identified 3529 pregnancies in women with ED prepregnancy: (i) 564 with continued antidepressant use before and during pregnancy; (ii) 778 with discontinued antidepressants before pregnancy; (iii) 2137 unexposed. Outpatient and inpatient postpartum visits for an ED or a mood/anxiety disorder constituted the outcome measures. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) using Cox regression with inverse probability of treatment weighting, and performed stratified analyses by antidepressant prescription filling in the first 3 months postpartum.

RESULTS

The weighted cumulative incidence for an ED visit at end of follow-up was 4.5% (continued) and 4.8% (discontinued). We found no association between continued antidepressant and postpartum ED visit, relative to discontinued (HR: 0.89, 95% CI: 0.52-1.52). The HR for postpartum mood/anxiety disorder visit was 1.27 (95% CI: 0.68-2.36) with continued antidepressants versus discontinued but decreased if more than two antidepressant prescriptions were refilled. Continued antidepressant use was associated with a 57% reduced likelihood of a postpartum ED visit versus discontinued use in pregnancies with antidepressant prescription refills in the early postpartum.

CONCLUSION

Among women with preexisting ED, there was no association between continued antidepressant use during pregnancy and the likelihood of postpartum psychiatric visits, relative to discontinued antidepressants before pregnancy. Continuation of treatment into the early postpartum is associated with reduced likelihood of postpartum ED visit.

PUBLIC SIGNIFICANCE

Based on data from the Danish registries, we identified 3529 pregnancies among women with preexisting eating disorders before pregnancy. Women with continued antidepressant treatment both before and during pregnancy did not have a lower probability of having postpartum psychiatric visits for an eating disorder or for mood/anxiety disorders (often coexisting with eating disorders), relative to those who discontinued antidepressants before pregnancy. Further continuation of antidepressant treatment into the early postpartum is associated with improved maternal postpartum outcomes. However, residual confounding by disease severity limits confidence in this conclusion.

Agreement between maternal report and medical records on use of medications during early pregnancy in New York

BACKGROUND

Studies evaluating associations between medication use in pregnancy and birth outcomes rely on various sources of exposure information. We sought to assess agreement between self-reported use of medications during early pregnancy and medication information in prenatal medical records to understand the reliability of each of these information sources.

METHODS

We compared self-reported prescription medication use in early pregnancy to medical records from 184 New York women with deliveries in 2018 who participated in the Birth Defects Study To Evaluate Pregnancy exposureS. We assessed medications used chronically and episodically, and medications within 12 therapeutic groups. We calculated agreement using kappa (κ) coefficients, sensitivity, and specificity. We assessed differences by case/control status, maternal age, education, time to interview, and interview language.

RESULTS

Medications used chronically showed substantial agreement between self-report and medical records (κ = 0.75, 0.61-0.88), with agreement for therapeutic groups used chronically ranging from κ = 0.61 for antidiabetics to κ = 1.00 for antihypertensives. Prescription medications used episodically showed worse agreement (κ = 0.40, 0.25-0.54), with the lowest agreement for opioid analgesics (κ = 0.20) and anti-infectives (κ = 0.33). Agreement did not differ by the characteristics examined, although we observed potential differences by interview language.

CONCLUSIONS

Among our sample, we observed good agreement between self-report and medical records for medications used chronically and substantially less agreement for medications used episodically. Differences by source may be due to poor recall in self-reports, non-adherence with prescribed medications and lack of complete prescription information within medical records. Limitations should be considered when assessing prescription medication exposures during early pregnancy in epidemiologic studies.

Prenatal Carbamazepine Exposure and Academic Performance in Adolescents: A Population-Based Cohort Study

BACKGROUND AND OBJECTIVES

To investigate whether children born to mothers who used carbamazepine during pregnancy had worse academic performance in adolescence.

METHODS

This population-based cohort study included all live-born singletons in Denmark between 1996 and 2002 who participated in the national ninth-grade exit examination (n = 370,859). Those born to mothers with prescription of antiseizure medications other than carbamazepine during pregnancy were excluded. We examined the association of in utero exposure to maternal carbamazepine redeemed during pregnancy (n = 290) with academic performance of offspring, defined by the scores in Danish and mathematics in ninth-grade exit examination. We estimated mean z-score difference with linear regression adjusted for socioeconomic factors and potential indications, including epilepsy and medication for other psychiatric disorders. Additional analyses addressing confounding by indication included comparison between in utero exposed vs past exposed and between past exposed and never exposed. In utero exposure to valproate monotherapy was used as a positive control and in utero exposure to lamotrigine as a negative control.

RESULTS

At the age of 16.1 (SD 0.4) years, adolescents in utero exposed to maternal carbamazepine monotherapy had lower scores both in Danish and mathematics in ninth-grade exit examination (adjusted z-score difference, -0.14 [95% CI -0.24 to -0.05] and -0.17 [95% CI -0.28 to -0.07], respectively). In utero exposure to carbamazepine monotherapy was associated with lower scores than past exposure only (adjusted z-score difference, -0.24 [95% CI -0.41 to -0.06] for Danish and -0.25 [95% CI -0.44 to -0.06] for mathematics), while past exposure to carbamazepine was associated with minor decrease in offspring's academic performance (adjusted z-score difference, -0.02 [95% CI -0.09 to 0.06] for Danish and -0.07 [95% CI -0.16 to 0.01] for mathematics). The association was also observed for in utero exposure to valproate monotherapy, but not for in utero exposure to lamotrigine.

DISCUSSION

In utero exposure to carbamazepine was associated with poorer academic performance in adolescence, as represented by lower scores in ninth-grade exit examination in Danish and mathematics. Additional studies are needed to confirm these findings because of limitations in this study and variable findings in prior studies.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that academic performance, as reflected in ninth-grade exit examinations in Danish and mathematics, was worse among those exposed to carbamazepine monotherapy in utero, compared with those without in utero exposure to antiseizure medications.

Cancer Risk in Children of Mothers With Epilepsy and High-Dose Folic Acid Use During Pregnancy

Importance

Women with epilepsy are recommended high doses of folic acid before and during pregnancy owing to risk of congenital anomalies associated with antiseizure medications. Whether prenatal exposure to high-dose folic acid is associated with increases in the risk of childhood cancer is unknown.

Objective

To assess whether high-dose folic acid supplementation in mothers with epilepsy is associated with childhood cancer.

Design, Setting, and Participants

Observational cohort study conducted with nationwide registers in Denmark, Norway, and Sweden from 1997 to 2017. Analyses were performed during January 10, 2022, to January 31, 2022. Mother-child pairs were identified in medical birth registers and linked with information from patient, prescription, and cancer registers, as well as with sociodemographic information from statistical agencies, and were categorized by maternal diagnosis of epilepsy. The study population consisted of 3 379 171 children after exclusion of 126 711 children because of stillbirth or missing or erroneous values on important covariates.

Exposures

Maternal prescription fills for high-dose folic acid tablets (≥1 mg daily) between 90 days before pregnancy start and birth.

Main Outcomes and Measures

First onset of childhood cancer at younger than 20 years. Cox proportional hazards models were used to calculate adjusted hazard ratios with corresponding 95% CIs, adjusted for potential confounders. Cumulative incidence at aged 20 years was used as a measure of absolute risk.

Results

The median age at the end of follow-up in the study population of 3 379 171 children was 7.3 years (IQR, 3.5-10.9 years). Among the 27 784 children (51.4% male) born to mothers with epilepsy, 5934 (21.4%) were exposed to high-dose folic acid (mean dose, 4.3 mg), with 18 exposed cancer cases compared with 29 unexposed, producing an adjusted hazard ratio of 2.7 (95% CI, 1.2-6.3), absolute risk if exposed of 1.4% (95% CI, 0.5%-3.6%), and absolute risk if unexposed of 0.6% (95% CI, 0.3%-1.1%). In children of mothers without epilepsy, 46 646 (1.4%) were exposed to high-dose folic acid (mean dose, 2.9 mg), with 69 exposed and 4927 unexposed cancer cases and an adjusted hazard ratio of 1.1 (95% CI, 0.9-1.4; absolute risk, 0.4% [95% CI, 0.3%-0.5%]). There was no association between children born to mothers with epilepsy who were prenatally exposed to antiseizure medications, but not high-dose folic acid, and an increased risk of cancer (absolute risk, 0.6%; 95% CI, 0.2%-1.3%).

Conclusions and Relevance

Prenatal exposure to high-dose folic acid was associated with increased risk of cancer in children of mothers with epilepsy.

Association of Prenatal Exposure to Antiseizure Medication With Risk of Autism and Intellectual Disability

Importance

Women with epilepsy frequently need antiseizure medication (ASM) to prevent seizures in pregnancy. Risk of neurodevelopmental disorders after prenatal exposure to AMSs is uncertain.

Objective

To determine whether children exposed prenatally to ASMs in monotherapy and duotherapy have increased risk of neurodevelopmental disorders.

Design, Setting, and Participants

The Nordic register-based study of antiepileptic drugs in pregnancy (SCAN-AED) is a population-based cohort study using health register and social register data from Denmark, Finland, Iceland, Norway, and Sweden (1996-2017; analysis performed February 2022). From 4 702 774 alive-born children with available mother-child identities and maternal prescription data, this study included 4 494 926 participants. Children from a multiple pregnancy or with chromosomal disorders or uncertain pregnancy length were excluded (n = 207 848).

Exposures

Prenatal exposure to ASM determined from maternal prescription fills between last menstrual period and birth.

Main Outcomes and Measures

We estimated cumulative incidence at age 8 years in exposed and unexposed children. Cox regression adjusted for potential confounders yielded adjusted hazard ratios (aHRs) with 95% CIs for autism spectrum disorder (ASD), intellectual disability (ID), or any neurodevelopmental disorder (ASD and/or ID).

Results

A total of 4 494 926 children were included; 2 306 993 (51.3%) were male, and the median (IQR) age at end of follow-up was 8 (4.0-12.1) years. Among 21 634 unexposed children of mothers with epilepsy, 1.5% had a diagnosis of ASD and 0.8% (numerators were not available because of personal data regulations in Denmark) of ID by age 8 years. In same-aged children of mothers with epilepsy exposed to topiramate and valproate monotherapy, 4.3% and 2.7%, respectively, had ASD, and 3.1% and 2.4% had ID. The aHRs for ASD and ID after topiramate exposure were 2.8 (95% CI, 1.4-5.7) and 3.5 (95% CI, 1.4-8.6), respectively, and after valproate exposure were 2.4 (95% CI, 1.7-3.3) and 2.5 (95% CI, 1.7-3.7). The aHRs were elevated with higher ASM doses compared with children from the general population. The duotherapies levetiracetam with carbamazepine and lamotrigine with topiramate were associated with increased risks of neurodevelopmental disorders in children of women with epilepsy: levetiracetam with carbamazepine: 8-year cumulative incidence, 5.7%; aHR, 3.5; 95% CI, 1.5-8.2; lamotrigine with topiramate: 8-year cumulative incidence, 7.5%; aHR, 2.4; 95% CI, 1.1-4.9. No increased risk was associated with levetiracetam with lamotrigine (8-year cumulative incidence, 1.6%; aHR, 0.9; 95% CI, 0.3-2.5). No consistently increased risks were observed for neurodevelopmental disorders after prenatal exposure to monotherapy with lamotrigine, levetiracetam, carbamazepin, oxcarbazepine, gapapentin, pregabalin, clonazepam, or phenobarbital.

Conclusions and Relevance

In this cohort study, prenatal exposure to topiramate, valproate, and several duotherapies were associated with increased risks of neurodevelopmental disorders.

Mirtazapine exposure in pregnancy and fetal safety: A nationwide cohort study

OBJECTIVE

To investigate the association between mirtazapine exposure in pregnancy and risk of specific adverse pregnancy outcomes.

METHODS

A register-based nationwide cohort study was conducted including all registered pregnancies in Denmark from 1997 to 2016. Mirtazapine-exposed pregnancies were compared with mirtazapine unexposed pregnancies in a 1:4 ratio matched according to propensity scores. Outcomes were major congenital malformations analyzed using log binomial models, and spontaneous abortion, stillbirth and neonatal death analyzed using Cox proportional hazard regression.

RESULTS

From a source population of 1,650,649 pregnancies, the propensity score-matched cohort included 4475 pregnancies (895 mirtazapine exposed) in the analysis of major congenital malformations. The analyses of spontaneous abortion included 9 500 pregnancies (1900 mirtazapine exposed), and for the analyses of stillbirths and neonatal deaths 9725 (1 945 mirtazapine-exposed) and 4485 pregnancies (897 mirtazapine-exposed) were included, respectively. Thirty-one (3.5%) children were diagnosed with major congenital malformation among the mirtazapine exposed compared with 152 (4.3%) among the unexposed pregnancies (OR=0.81, 95% CI 0.55-1.20). Spontaneous abortion occurred in 237 (12.5%) of the mirtazapine exposed compared with 931 (12.3%) of the unexposed pregnancies (HR = 1.04%, 95% CI 0.91-1.20). The analyses revealed no increased risk of stillbirth (HR = 0.88%, 95% CI 0.34-2.29) or neonatal death (HR = 0.60%, 95% CI 0.18-2.02).

CONCLUSIONS

In this nationwide Danish register study, mirtazapine exposure in pregnancy was not associated with major congenital malformations, spontaneous abortion, stillbirth, or neonatal death. Clinicians and patients can be reassured that mirtazapine is safe in pregnancy.

Antidepressant use during pregnancy and risk of adverse neonatal outcomes: A comprehensive investigation of previously identified associations

OBJECTIVE

Prenatal antidepressant use is widespread. Observational studies have investigated the neonatal effects of prenatal antidepressant exposure with inconclusive results. We aimed to comprehensively investigate the associations between prenatal antidepressant exposure and the most commonly studied adverse neonatal outcomes: preterm birth, birthweight, poor neonatal adaptation, persistent pulmonary hypertension of the neonate (PPHN), neonatal admission and congenital malformations.

METHODS

We included 45,590 singletons (born 1997-2015) whose mothers used antidepressants within one year before pregnancy. Children were categorised into two groups: continuation (antidepressant use before and during pregnancy) or discontinuation (antidepressant use before but not during pregnancy). We applied random-effects logistic and linear regressions, adjusting for covariates.

RESULTS

After adjusting for confounders, prenatal antidepressant exposure was associated with a 2.3 day (95% CI -2.9; -2.0) decrease in gestational age and a 51 g (95% CI -62g; -41 g) decrease in birthweight. The continuation group was at increased risk for moderate-to-late preterm birth (32-37 weeks) (aOR = 1.43; 95%CI 1.33; 1.55), moderately low birthweight (1500-2499 g) (aOR = 1.28; 95%CI 1.17; 1.41), postnatal adaptation syndrome (aOR = 2.59; 95%CI 1.87; 3.59) and neonatal admission (aOR = 1.52; 95%CI 1.44; 1.60) compared to the discontinuation group.

CONCLUSION

Prenatal antidepressant exposure was associated with small decreases in gestational age and birthweight, as well as higher risk for moderate-to-late preterm birth, moderately low birthweight, neonatal admission and postnatal adaptation syndrome. No differences in risk were found for PPHN, or congenital malformations. The causality of the observed associations cannot be established due to the potential for unmeasured residual confounding linked to the underlying disease.

Adherence to treatment for hypothyroidism in pregnancy and relationship with thyrotropin control: a retrospective observational cohort study

Background

Hypothyroidism is the second most common endocrinological disease during pregnancy, with percentages that can range between 3.2 and 5.5%. A good maternal and foetal health outcome depends on thyroid hormone replacement therapy. The goal of such therapy is to maintain thyrotropin (TSH) in a range that is specific for pregnant women and varies between the trimesters of pregnancy. In our study, we wanted to analyse the adherence to hypothyroidism treatment among pregnant women and to evaluate the degree of control of the disease.

Methods

We performed a retrospective observational cohort study in pregnant women between 2012 and 2018 in the Lleida health region. Therapeutic adherence was analysed by the proportion of days covered (PDC). The relationship with other variables was assessed using the regression coefficients and their 95% confidence interval (CI).

Results

We examined a sample of 17,281 women, representing more than 92% of the pregnant women in the Lleida health region in the period analysed. Among this sample, the mean prevalence of hypothyroidism was 6.52% (0.07% clinical and 6.45% subclinical). 3.3% of the 17,281 pregnant women were treated. Among them, the mean adherence score was 79.6 ± 22.2. Of these, 54% presented high adherence. The latter had a higher mean age and better TSH control, in comparison to the ones showing low adherence.

Conclusions

Half of the treated patients had good adherence to treatment and a better TSH control, in comparison to the others. Most of them achieved a good control at the third trimester of pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04483-8.

Maternal Epilepsy and Long-term Offspring Mortality - a Nationwide Cohort Study

Objective

We examined how maternal epilepsy and use of antiseizure medications in pregnancy was associated with offspring mortality.

Methods

This population‐based cohort study included all live‐ and stillborn singletons in Denmark between 1981 and 2016. We used nation‐wide registers to retrieve information on pregnancy characteristics, epilepsy diagnoses, use of antiseizure medications, and mortality. Adjusted mortality rate ratios (MRR) were estimated using log‐linear Poisson regression.

Results

The cohort consisted of 1,862,474 children. In total, 12,026 live‐born children died during follow‐up, of whom 170 (1.4%) were offspring of mothers with epilepsy. Overall mortality was increased in offspring of mothers with epilepsy compared to offspring of mothers without epilepsy (MRR = 1.46, 95% CI: 1.23–1.71), driven by an excess mortality only in the first year of life. Mortality was increased for natural deaths (MRR = 1.50, 95% CI: 1.25–1.78) but not from unnatural deaths (MRR = 1.38, 95% CI: 0.84–2.14), and only in offspring of women with epilepsy who used antiseizure medications during pregnancy (MRR = 1.51, 95% CI: 1.00–2.17), but not in offspring of women with epilepsy who did not use antiseizure medications while pregnant (MRR = 0.97, 95% CI: 0.69–1.31). When analyses were restricted to children born from 2000 and onwards, the excess mortality that was observed in the first year of life among children of mothers with epilepsy, was no longer evident.

Interpretation

During the 1981 to 1999 epoch, offspring of women with epilepsy were at increased risk of dying in the first year of life. However, this risk did not extend to children born after 2000. Future retrospective studies of the effects of maternal epilepsy on the health of the offspring should take this difference into account. ANN NEUROL 2022;91:455–465

Postoperative epilepsy and survival in glioma patients: a nationwide population-based cohort study from 2009 to 2018

PURPOSE

Postoperative epilepsy is common in glioma patients and has been suggested to indicate disease progression, yet knowledge of its role as a prognostic factor is limited. This study investigates the association between postoperative epilepsy and survival amongst patients with gliomas.

METHODS

We included 3763 patients with histopathologically diagnosed grade II, III, and IV gliomas from 2009 to 2018 according to the Danish Neuro-Oncology Registry. Information on epilepsy diagnosis was redeemed from the Danish National Patient Registry, the National Prescription Registry and the Danish Neuro-Oncology Registry. We used Cox proportional hazards models with 95% confidence intervals (CIs) to examine hazard ratios (HRs) for the association between postoperative epilepsy and risk of death. We examined the role of the timing of epilepsy in three different samples: Firstly, in all glioma patients with postoperative epilepsy; secondly, in patients with postoperative de novo epilepsy; thirdly, exclusively in a homogeneous sub-group of grade IV patients with postoperative de novo epilepsy.

RESULTS

Glioma patients with postoperative epilepsy had an increased risk of death, regardless of prior epilepsy status (HR = 4.03; CI 2.69-6.03). A similar increase in the risk of death was also seen in patients with postoperative de novo epilepsy (HR = 2.08; CI 1.26-3.44) and in the sub-group of grade IV patients with postoperative de novo epilepsy (HR = 1.83; CI 1.05-3.21).

CONCLUSIONS

Postoperative epilepsy may negatively impact survival after glioma diagnosis, regardless of preoperative epilepsy status. Postoperative epilepsy may be an expression of a more invasive growth pattern of the gliomas following primary tumor treatment.

Antidepressant discontinuation before or during pregnancy and risk of psychiatric emergency in Denmark: A population-based propensity score-matched cohort study

BACKGROUND

Women prescribed antidepressants face the dilemma of whether or not to continue their treatment during pregnancy. Currently, limited evidence is available on the efficacy of continuing versus discontinuing antidepressant treatment during pregnancy to aid their decision. We aimed to estimate whether antidepressant discontinuation before or during pregnancy was associated with an increased risk of psychiatric emergency (ascertained by psychiatric admission or emergency room visit), a proxy measure of severe exacerbation of symptoms/mental health crisis.

METHODS AND FINDINGS

We carried out a propensity score-matched cohort study of women who gave birth to live-born singletons between January 1, 1997 and June 30, 2016 in Denmark and who redeemed an antidepressant prescription in the 90 days before the pregnancy, identified by Anatomical Therapeutic Chemical (ATC) code N06A. We constructed 2 matched cohorts, matching each woman who discontinued antidepressants before pregnancy (N = 2,669) or during pregnancy (N = 5,467) to one who continued antidepressants based on propensity scores. Maternal characteristics and variables related to disease severity were used to generate the propensity scores in logistic regression models. We estimated hazard ratios (HRs) of psychiatric emergency in the perinatal period (pregnancy and 6 months postpartum) using stratified Cox regression. Psychiatric emergencies were observed in 76 women who discontinued antidepressants before pregnancy and 91 women who continued. There was no evidence of higher risk of psychiatric emergency among women who discontinued antidepressants before pregnancy (cumulative incidence: 2.9%, 95% confidence interval [CI]: 2.3% to 3.6% for discontinuation versus 3.4%, 95% CI: 2.8% to 4.2% for continuation; HR = 0.84, 95% CI: 0.61 to 1.16, p = 0.298). Overall, 202 women who discontinued antidepressants during pregnancy and 156 who continued had psychiatric emergencies (cumulative incidence: 5.0%, 95% CI: 4.2% to 5.9% versus 3.7%, 95% CI: 3.1% to 4.5%). Antidepressant discontinuation during pregnancy was associated with increased risk of psychiatric emergency (HR = 1.25, 95% CI: 1.00 to 1.55, p = 0.048). Study limitations include lack of information on indications for antidepressant treatment and reasons for discontinuing antidepressants.

CONCLUSIONS

In this study, we found that discontinuing antidepressant medication during pregnancy (but not before) is associated with an apparent increased risk of psychiatric emergency compared to continuing treatment throughout pregnancy.

Association of Maternal Antidepressant Prescription During Pregnancy With Standardized Test Scores of Danish School-aged Children

IMPORTANCE

Concerns exist about long-term neurodevelopmental consequences of prenatal exposure to antidepressants.

OBJECTIVE

To evaluate whether maternal prescription fill for antidepressants in pregnancy was associated with performance in standardized tests among Danish schoolchildren.

DESIGN, SETTING, AND PARTICIPANTS

Population-based retrospective cohort study of children born in Denmark between January 1, 1997, and December 31, 2009, attending public primary and lower secondary school. The children included had completed a language or mathematics test as part of the Danish National Test Program between January 1, 2010, and December 31, 2018. The age range of the eligible schoolchildren was 7 to 17 years.

EXPOSURES

Maternal prescription fill for antidepressants during pregnancy, obtained from the Danish Prescription Register.

MAIN OUTCOMES AND MEASURES

The difference in standardized scores between children with and without maternal prescription fill for antidepressants in mathematics and language tests (scale, 1-100; higher scores indicate better test results) was estimated using linear regression models, adjusted for relevant confounders. Ten sensitivity analyses were performed, including a sibling-controlled analysis.

RESULTS

Among the 575 369 children included (51.1% males), 10 198 (1.8%) were born to mothers filling an antidepressant prescription during pregnancy. The mean (SD) age of children at the time of testing spanned from 8.9 (0.4) years in grade 2 to 14.9 (0.4) years in grade 8. Maternal prescription fill for antidepressants was significantly associated with a poorer performance in mathematics (mean test scores for the group exposed to maternal antidepressant fill: 52.1 [95% CI, 51.7-52.6] and for the group not exposed to maternal antidepressant fill: 57.4 [95% CI, 57.3-57.4]; adjusted difference, -2.2 [95% CI, -2.7 to -1.6]), but not in language (mean test scores for the exposed group: 53.4 [95% CI, 53.1-53.7] and for the not exposed group: 56.6 [95% CI, 56.5-56.6]; adjusted difference, -0.1 [95% CI, -0.6 to 0.3]). In the sibling-controlled analysis, the adjusted difference in mathematics (mean scores for the exposed group: 53.5 [95% CI, 52.7-54.3] and for the not exposed group: 59.0 [95% CI, 58.9-59.1]) was -2.8 (95% CI, -4.5 to -1.2) and in language (mean test scores for the exposed group: 53.9 [95% CI, 53.2-54.6] and for the not exposed group: 56.6 [95% CI, 56.5-56.7]) was -0.3 (95% CI, -1.9 to 1.2).

CONCLUSIONS AND RELEVANCE

In this study of public schoolchildren in Denmark, children whose mothers had filled prescriptions for antidepressants during pregnancy, compared with children whose mothers did not fill prescriptions for antidepressants during pregnancy, had a 2-point lower standardized test score in mathematics, a difference that was statistically significant, but had no significant difference in language test scores. The magnitude of the difference in the mathematics test score was small and of uncertain clinical importance, and the findings must be weighed against the benefits of treating maternal depression during pregnancy.

Antibiotic exposure during pregnancy and childhood asthma: a national birth cohort study investigating timing of exposure and mode of delivery

OBJECTIVE

To investigate whether antibiotic exposure during pregnancy was associated with childhood asthma and if this relationship was conditional on timing of exposure and mode of delivery.

DESIGN

A cohort study using multivariable logistic regression models adjusting for a priori defined confounders. Pregnant women were recruited from 1996 to 2002.

SETTING

The Danish National Birth Cohort.

PATIENTS

Of the 96 832 children in the cohort, 32 651 children were included in the study population.

MAIN OUTCOME MEASURE

Parent-reported childhood asthma at 11 years.

RESULTS

A total of 5522 (17%) children were born to mothers exposed to antibiotics during pregnancy. In adjusted analyses, children born to exposed mothers had higher odds of asthma (OR 1.14, 95% CI 1.05 to 1.24). There was no association with antibiotic exposure in the first trimester (OR 1.02, 95% CI 0.83 to 1.26), but higher odds were observed for antibiotic exposure in the second to third trimester (OR 1.17, 95% CI 1.06 to 1.28), compared with unexposed children. The overall association between antibiotics during pregnancy and childhood asthma was only observed in vaginally born children (OR 1.17, 95% CI 1.07 to 1.28) but not in caesarean section born children (planned caesarean section: OR 0.95, 95% CI 0.66 to 1.37; caesarean emergency: OR 0.96, 95% CI 0.73 to 1.28). In exposed vaginally born children, the odds for childhood asthma requiring treatment during the preceding year were 34% higher (OR 1.34, 95% CI 1.21 to 1.49), compared with unexposed vaginally born children.

CONCLUSIONS

Antibiotic exposure in mid-to-late pregnancy is associated with higher odds of childhood asthma in vaginally born children. Mode of delivery may modify the association.

Long-term prenatal effects of antidepressant use on the risk of affective disorders in the offspring: a register-based cohort study

To investigate the association between intrauterine antidepressant exposure and offspring affective disorders over an 18-year follow-up period using Danish national registers. We included 42,988 singletons born during 1998-2011 and followed-up until 2016, death, emigration, or date of first affective disorder diagnosis. Children were categorised into two groups according to maternal antidepressant use within 2 years before and during pregnancy: continuation (use before and during pregnancy) or discontinuation (use before but not during pregnancy). The outcome was an affective disorders diagnosis in the offspring based on secondary/tertiary care records and primary care prescription data. Hazard ratios (HR) of affective disorders were estimated using Cox regression models. To consider confounding by shared environmental or genetic factors, we investigated the effect of paternal antidepressant use on the risk for affective disorders. Affective disorders were diagnosed in 1538 children. Children whose mothers continued antidepressants during pregnancy had an increased risk of affective disorders (HR = 1.20, 95% CI = 1.08-1.34), compared with children whose mothers discontinued before pregnancy. Similarly, continued paternal antidepressant use during pregnancy was associated with higher risk for offspring affective disorders (HR = 1.29, 95% CI = 1.12-1.49), compared to discontinuation. Based on data from primary and secondary/tertiary care, maternal antidepressant use during pregnancy was associated with an increased risk of affective disorders in the offspring. As similar associations were observed in children whose fathers continued antidepressant use across the pregnancy period, the observed association may be attributable to the underlying parental psychopathology, rather than the direct intrauterine exposure to antidepressants.

Association of Prenatal Exposure to Valproate and Other Antiepileptic Drugs With Intellectual Disability and Delayed Childhood Milestones

Importance

There is concern about neurodevelopmental outcomes associated with prenatal exposure to valproate and other antiepileptic drugs (AEDs) among children of mothers with or without epilepsy.

Objective

To study the risk of intellectual disability and delayed development in childhood milestones among children of women who used valproate or other AEDs during pregnancy.

Design, Setting, and Participants

This population-based cohort study analyzed information on use of AEDs from the Danish National Prescription Registry and register diagnoses from the Danish Psychiatric Central Research Register and Danish National Patient Registry. The study included all live-born singletons in Denmark from January 1, 1997, to December 31, 2011. Data were analyzed in April 2020.

Exposures

Prenatal exposure to maternal valproate and other AEDs.

Main Outcomes and Measures

The main measures were adjusted Cox regression estimates of hazard ratios (aHRs) for intellectual disability and a combined outcome of intellectual disability with delayed childhood milestones.

Results

A total of 913 302 children (468 708 [51.3%] boys; mean [SD] age, 10.3 [4.4] years and median [interquartile range] age, 10.1 [6.5-14.0] years at final follow-up) were identified and contributed more than 10.2 million person-years of observation, including 580 children exposed to valproate (302 [51.3%] boys). At end of follow-up, 6958 children (0.8%) were identified as having intellectual disability and 14 967 children (1.6%) were identified as having intellectual disability with delayed childhood milestones. Compared with offspring not exposed to valproate prenatally, offspring of women who used valproate during pregnancy had increased risk of intellectual disability (aHR, 4.48; 95% CI, 2.97-6.76) and intellectual disability with delayed childhood milestones (aHR, 6.07; 95% CI, 4.67-7.89). Among mothers with epilepsy, offspring exposed prenatally to valproate had increased risk of intellectual disability (aHR, 1.95; 95% CI, 1.21-3.14) and intellectual disability with delayed childhood milestones (aHR, 3.07; 95% CI, 2.24-4.20) compared with offspring without prenatal exposure. Compared with offspring without prenatal exposure to AEDs, increased risk of intellectual disability was identified in children with prenatal exposure to maternal monotherapy use of carbamazepine (aHR, 3.84; 95% CI, 2.32-6.38), clonazepam (aHR, 2.41; 95% CI, 1.09-5.35), and oxcarbazepine (aHR, 3.70; 95% CI, 2.11-6.51) but not lamotrigine (aHR, 1.33; 95% CI, 0.71-2.48).

Conclusions and Relevance

These findings suggest that prenatal exposure to valproate was associated with increased risk of intellectual disability and delayed childhood milestones. Statistically significant associations were also found for prenatal exposure to other AEDs. These findings suggest that women of childbearing potential may need to be counseled on use of AEDs.

Adherence with prescription drugs in pregnant and breastfeeding women consulting with the Israel Poison Information Center Teratology Service

INTRODUCTION

During pregnancy and breastfeeding, many women require prescription medications. Concerns about drug effects on the fetus or breastfed infant may lead to decreased adherence. Our objective was to evaluate the adherence of pregnant and breastfeeding Israeli women to prescription drugs, the information they received regarding drug safety, and the women's awareness and pattern of the use of Teratogen Information Services (TIS) in Israel.

METHODS

We conducted a prospective observational cohort study among pregnant and breastfeeding women who had contacted the Israel Poison Information Center (IPIC) to consult about prescription medications. In a follow-up telephone call, we assessed adherence (defined as medication initiation by the time of the follow-up call) and the patients' recollection of the safety information given by the prescribing physician. In an additional cohort of post-partum women, we assessed their awareness about TIS in Israel.

RESULTS

We included 59 pregnant women (62 prescriptions), 75 breastfeeding women (80 prescriptions), and 49 postpartum women. About two-thirds of all prescriptions were for antimicrobial drugs. By the time of the follow-up call, most participants (89% of pregnant and 89% of breastfeeding women) had initiated medications. Eight (11%) breastfeeding women stopped breastfeeding their babies while using the medication. Patients reported receiving explicit and unequivocal information concerning medication safety by the prescriber for 50% and 55% of prescriptions to pregnant and breastfeeding women, respectively. 70% of postpartum women interviewed in the maternity ward were not aware of TIS in Israel.

DISCUSSION AND CONCLUSIONS

We observed high adherence rate to prescription medication therapy among pregnant and breastfeeding women in our cohort. Only about half of the women reported receiving comprehensive drug safety information by the prescriber. Raising awareness of the importance of medication safety counseling among both physicians and patients may contribute to the quality of medical care of pregnant and breastfeeding women in Israel.

Misleading meta-analyses of observational studies may generate unjustified alarms: The case of medications for nausea and vomiting in pregnancy

OBJECTIVES

Because observational studies often use imperfect measurements, results are prone to misclassification errors. We used as a motivating example the possible teratogenic risks of antiemetic agents in pregnancy since a large observational study recently showed that first-trimester exposure to doxylamine-pyridoxine was associated with significantly increased risk of congenital malformations as a whole, as well as central nervous system defects, and previous observational studies did not show such associations. A meta-analysis on this issue was carried out with the aim to illustrate how differential exposure and outcome misclassifications may lead to uncertain conclusions.

METHODS

Medline, searched to October 2019 for full text papers in English. Summary Odds Ratios (ORs) with confidence intervals (CIs) were calculated using random-effect models. Probabilistic sensitivity analyses were performed for evaluating the extension of differential misclassification required to account for the exposure-outcome association.

RESULTS

Summary ORs were 1.02 (95 % CI, 0.92-1.15), 0.99 (0.82-1.19) and 1.25 (1.08-1.44) for overall congenital, cardiocirculatory, and central nervous system malformations respectively. By assuming exposure and outcome bias factor respectively of 0.95 (i.e., newborns with congenital defects had exposure specificity 5% lower than healthy newborns) and 1.12 (i.e., exposed newborns had outcome sensitivity 12 % higher than unexposed newborns), summary OR of central nervous system defects became 1.13 (95 % CI, 0.99-1.29) and 1.17 (95 % CI, 0.99-1.38).

CONCLUSION

Observational investigations and meta-analyses of observational studies need cautious interpretations. Their susceptibility to several, often sneaky, sources of bias should be carefully evaluated.

Modeling exposures of medications used episodically during pregnancy: Triptans as a motivating example

PURPOSE

To assess the validity of dispensed prescription to classify exposure to medications used episodically during pregnancy, and to explore individual trajectories of episodic medication use across pregnancy, using triptans for migraine as the motivating example.

METHODS

We compared self-reported triptan use during pregnancy in The Norwegian Mother, Father and Child Cohort Study (MoBa) to dispensed prescriptions in The Norwegian Prescription Database and calculated Cohen's kappa coefficient (κ), sensitivity, specificity and predictive values using MoBa as reference standard. We used group-based trajectory modeling to estimate exposure trajectories in MoBa according to probability of triptan use across pregnancy.

RESULTS

We identified 6051 pregnancies where mothers filled at least one triptan prescription or reported migraine or triptan use in the 6 months before or during pregnancy. Sensitivity of prescribed triptans during pregnancy was low (39.1%), but specificity was quite high (95.4%). Agreement between the two data sources was fair (κ 0.36). We identified three trajectory groups in MoBa including constant-high, decreasing-medium and decreasing-low probability of triptan use across pregnancy.

CONCLUSIONS

Using dispensed prescriptions rather than self-report to classify exposure to triptans during pregnancy is likely to result in substantial under-estimation of exposure. In this study, traditional definitions of ever-exposed vs never-exposed failed to capture variations in drug utilization during pregnancy.

Patterns of prescription medicine dispensing before and during pregnancy in New Zealand, 2005-2015

Objective

To describe prescription medicine dispensing before and during pregnancy in New Zealand, 2005–2015.

Methods

Members of the New Zealand Pregnancy Cohort were linked with their dispensing records in a national database of prescription products dispensed from community pharmacies. We identified the proportion of pregnancies during which at least one prescription medicine was dispensed, the number of different medicines used and the most commonly dispensed medicine groups both during pregnancy and in the 270 days before conception. Dispensing during pregnancy was assessed by several maternal characteristics.

Results

874,884 pregnancies were included. Over the study timeframe, the proportion of pregnancies exposed to a non-supplement prescription medicine increased from 38.5% to 67.2%. The mean number of different non-supplement medicines dispensed during pregnancy increased from 2.5 to 3.2. Dispensing during pregnancy was weakly associated with body mass index, smoking status and ethnicity. Pregnancy exposure was highest for Antibacterials (26.0%), Analgesics (16.7%) and Antinausea & Vertigo Agents (11.0%).

Conclusions

From 2005–2015, both the proportion of exposed pregnancies and the number of different medicines dispensed to pregnant women in New Zealand increased.

Prenatal exposure to antibiotics and timing of puberty in sons and daughters: A population-based cohort study

OBJECTIVE

To investigate if prenatal exposure to antibiotics is associated with earlier timing of pubertal development in sons and daughters.

STUDY DESIGN

This population-based cohort study is based upon the Puberty Cohort and includes a sample of 15,638 children born 2000-2003 in Denmark. Information on maternal use of antibiotics was collected around gestational week 30 and 6 months postpartum. The children were followed-up half-yearly from 11 years of age and throughout sexual maturation providing information on Tanner stages, acne and axillary hair, in addition to voice break and first ejaculation in sons and menarche in daughters. Due to the half-yearly collection of data on pubertal timing, the data was censored and therefore analysed using a multivariable censored time-to-event regression model. We examined both prenatal exposure to antibiotics at any time in pregnancy and trimester-specific prenatal exposure to antibiotics and pubertal timing, adjusting for maternal baseline socioeconomic and lifestyle characteristics. Mean age differences for the pubertal milestones between exposure groups were estimated. A combined estimate for overall pubertal timing was calculated based on combining all pubertal milestones into one model for sons and daughters, using Huber-White robust variance estimation which handles the risk of type 1 errors due to multiple testing of correlated outcomes. An active comparator approach with restriction to women reporting to have a urinary tract infection (cystitis) treated with either penicillin or sulfonamides was employed in a sub-analysis.

RESULTS

The prevalence of any maternal use of antibiotics in pregnancy was 21.1 %. There was no association between prenatal exposure to antibiotics and timing of pubertal development for the individual milestones. The adjusted combined estimate for pubertal timing in sons prenatally exposed to antibiotics at any point in pregnancy was -0.4 (95 % confidence interval (CI): -1.2; 0.4) months compared to unexposed sons. The adjusted combined estimate for pubertal timing in daughters prenatally exposed to antibiotics at any point in pregnancy was -0.1 (95 % CI: -0.9; 0.7) months compared to unexposed daughters. Both the trimester-specific analyses and the active comparator analysis revealed similar results.

CONCLUSION

Prenatal exposure to antibiotics was not associated with pubertal timing.

Maternal exposure to ibuprofen can affect the programming of the hypothalamus of the male offspring

Ibuprofen, a non-steroidal anti-inflammatory drug, inhibits the activity of cyclooxygenase enzyme, leading to reduction in Prostaglandin E₂ (PGE₂) production. Due to the importance of PGE₂ in promoting the brain masculinization in male fetus, this study aimed to evaluate the effects of in utero and lactational exposure to ibuprofen and their late repercussions on reproductive parameters in male rats. Pregnant rats were exposed to ibuprofen (10, 30 or 60 mg/kg) or vehicle (control group) per gavage daily from gestational day 15 to day 21 after birth, and late reproductive effects were assessed during the sexual development and in the reproductive adult life in the male offspring. Males exposed to ibuprofen had a decrease in body weight and anogenital distance, as well as a delay in the ages of testicular descent and preputial separation. In adulthood, there was a decrease in the Leydig cells nuclei volume, testosterone levels and percentage of normal sperm morphology. All animals exposed to ibuprofen presented male copulatory behavior, however, in the presence of another male, they also presented a female-typical behavior. Maternal exposure to ibuprofen during the sensitive windows of brain development adversely impacted the reproductive parameters of male rats, suggesting an incomplete masculinization of the hypothalamus.

In Utero Exposure to Glucocorticoids and Pubertal Timing in Sons and Daughters

Early pubertal timing has been associated with adult diseases, and identifying preventable causes is of importance. In utero exposure to exogenous glucocorticoids, has been associated with changes in the reproductive hormonal axes in the children, which may influence pubertal timing. Exogenous glucocorticoids can be indicated for diseases such as asthma, allergy, skin diseases, as well as muscle and joint diseases. The aim was to explore the association between in utero exposure to glucocorticoids and pubertal timing in the children. This population-based study was conducted in the Puberty Cohort including 15,819 children, which is a sub-cohort of the Danish National Birth Cohort. Information on maternal glucocorticoid treatment was collected through interviews during pregnancy. Information on pubertal timing was obtained by questionnaires every 6 months throughout puberty, including Tanner Stages, axillary hair, acne, voice break, first ejaculation and menarche. The potential impact of confounding by indication was explored by stratifying on indication and treatment status. Overall, 6.8% of the children were exposed to glucocorticoids in utero. Exposure to glucocorticoids in utero was not associated with earlier puberty for neither boys nor girls with combined estimates of 0.4 months (95% CI: –1.5; 2.2) and –0.7 months (95% CI: –2.5; 1.2).

Association Between Prenatal Valproate Exposure and Performance on Standardized Language and Mathematics Tests in School-aged Children

Importance

Valproate sodium is used for the treatment of epilepsy and other neuropsychiatric disorders in women of childbearing potential. However, there are concerns about impaired cognitive development in children who have been exposed to valproate during pregnancy.

Objective

To estimate the association between long-term school performance and prenatal exposure to valproate and a number of other antiepileptic drugs (AEDs).

Design, Setting, and Participants

In a prospective, population-based cohort study conducted from August 1, 2015, to May 31, 2017, data used in the study were provided by Statistics Denmark on April 15, 2016. All children born alive in Denmark between 1997 and 2006 (n = 656 496) were identified. From this cohort, children who did not participate in the national tests, with presumed coding errors in gestational age and children missing information on their mother's educational level or household income were excluded (n = 177 469) leaving 479 027 children for the analyses. Children were identified and linked across national registers that had information on exposure, covariates, and outcome. The primary outcome was performance in national tests, an academic test taken by students in Danish primary and lower secondary state schools. We assessed performance in Danish and mathematics at different grades among valproate-exposed children and compared their performance with that of unexposed children and children exposed to another AED (lamotrigine). Test scores were standardized to z scores and adjusted for risk factors.

Main Outcome and Measures

Difference in standardized z scores in Danish and mathematics tests among valproate-exposed children compared with unexposed and lamotrigine-exposed children.

Results

Of the 656 496 children identified, 479 027 children who participated in the national tests were evaluated, including children exposed to the following AEDs in monotherapy: valproate, 253; phenobarbital, 86; oxcarbazepine, 236; lamotrigine, 396; clonazepam, 188; and carbamazepine, 294. The mean (SD) age of the 244 095 children completing the sixth-grade Danish test was 12.9 (0.39) years; 122 774 (50.3%; 95% CI, 50.1% to 50.5%) were boys and 121 321 (49.7%; 95% CI, 49.5% to 49.9%) were girls. Valproate-exposed children scored worse on the sixth-grade Danish tests (adjusted difference, -0.27 SD; 95% CI, -0.42 to -0.12) and sixth-grade mathematics tests (adjusted difference, -0.33 SD; (95% CI, -0.47 to -0.19) compared with unexposed children and children exposed to lamotrigine (adjusted difference, -0.33 SD; 95% CI, -0.60 to -0.06). Also, children exposed to clonazepam scored worse in the sixth-grade Danish tests (adjusted difference, -0.07 SD; 95% CI, -0.12 to -0.02). Carbamazepine, lamotrigine, phenobarbital, and oxcarbazepine were not linked to poor school performance compared with unexposed children.

Conclusions and Relevance

Maternal use of valproate was associated with a significant decrease in school performance in offspring compared with children unexposed to AEDs and children exposed to lamotrigine. Findings of this study further caution against the use of valproate among women of childbearing potential.

Exposure to antazoline-naphazoline eye drops during pregnancy and the risk of congenital malformations: a Danish nationwide cohort study

PURPOSE

To investigate whether exposure to antazoline-naphazoline eye drops in the first trimester of pregnancy was associated with an increased risk of malformations in humans.

METHODS

All women giving live birth between 1997 and 2011 in Denmark were included in this nationwide cohort study. All women redeeming at least one prescription of antazoline-naphazoline eye drops during the first 84 days of pregnancy were identified. Logistic regression was used to estimate the odds ratios of malformations among exposed offspring compared to non-exposed offspring.

RESULTS

We identified 977 706 births between 1997 and 2011. A total of 3061 women (0.32%) were exposed to antazoline-naphazoline eye drops in the first trimester of pregnancy. The rate of congenital malformations was 3.0% (n = 93) in exposed offspring and 3.5% (n = 33 594) in unexposed offspring. First-trimester exposure to antazoline-naphazoline was not associated with major congenital malformations overall (odds ratio: 0.88, 95% confidence interval: 0.71-1.09) or with any specific major malformation. The number of redeemed prescriptions was unchanged during all trimesters of pregnancy as compared to before and after pregnancy (p < 0.05).

CONCLUSION

Exposure to antazoline-naphazoline eye drops in the first trimester of pregnancy appears not to be associated with increased teratogenic risk.

Use of Negative Control Exposure Analysis to Evaluate Confounding: An Example of Acetaminophen Exposure and Attention-Deficit/Hyperactivity Disorder in Nurses' Health Study II

Frequent maternal use of acetaminophen in pregnancy has been linked to attention-deficit/hyperactivity disorder (ADHD) in children, but concerns regarding uncontrolled confounding remain. In this article, we illustrate use of the negative control exposure (NCE) approach to evaluate uncontrolled confounding bias in observational studies on pregnancy drug safety and explain the causal assumptions behind the method. We conducted an NCE analysis and evaluated the associations between maternal acetaminophen use during different exposure periods and ADHD among 8,856 children born in 1993-2005 to women enrolled in the Nurses' Health Study II cohort. Information on regular maternal acetaminophen use was collected prospectively in biennial questionnaires. A total of 721 children (8.1%) in the cohort had been diagnosed with ADHD as reported by the mothers. Our NCE analysis suggested that only acetaminophen use at the time of pregnancy was associated with childhood ADHD (odds ratio = 1.34, 95% confidence interval: 1.05, 1.72), and the effect estimates for the 2 NCE periods (about 4 years before and 4 years after the pregnancy) were null. Our findings corroborate those of prior reports suggesting that prenatal acetaminophen exposure may influence neurodevelopment. The lack of an association between acetaminophen use in the pre- and postpregnancy exposure periods and ADHD provides assurance that uncontrolled time-invariant factors do not explain this association.

Developmental outcomes at age four following maternal antiepileptic drug use

We investigated whether prenatal antiepileptic drug (AED) exposure was associated with adverse outcomes in the Before School Check (B4SC) assessments, particularly the assessments measuring neurodevelopment. Children exposed to AEDs were identified by linking women dispensed AEDs in the Pharmaceutical Collection to births recorded on the National Minimum Dataset (NMDS). Multinomial logistic regression was used to estimate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for outcomes of the parent-completed Parental Evaluation of Developmental Status (PEDS) questionnaire and Strengths and Difficulties Questionnaire (SDQ), after adjusting for gender, ethnicity, and socioeconomic deprivation. Between 2012 and 2016, 606 children with a mother who had been dispensed one or more AEDs during pregnancy had taken part in the B4SC. Prenatal exposure to sodium valproate (n = 161) or lamotrigine (n = 149) monotherapy was associated with an increased risk of having an abnormal SDQ - parent-completed (SDQP) score, ≥17 - indicating emotional or behavioral concerns (9.32% of children exposed to sodium valproate monotherapy had an abnormal score; aRR: 2.11; 1.23-3.63; lamotrigine 8.05%; aRR: 2.21; 1.21-4.02). Prenatal exposure to carbamazepine monotherapy (n = 201) was not associated with an increased risk of having an abnormal total SDQP score but was associated with increased risks in the individual domains of the SDQP. Prenatal exposure to AED polytherapy (n = 57) was associated with the highest risk of abnormal SDQP scores (17.54% of children exposed to polytherapy had abnormal scores; aRR: 2.75; 1.25-6.02). Prenatal exposure to sodium valproate and lamotrigine is associated with an increased risk of concerns about emotional and behavioral development being reported by parents in a neurodevelopmental screening program. Additional investigation is required into why significant differences between AEDs were not seen in this study.

Use of biologics during pregnancy and risk of serious infections in the mother and baby: a Canadian population-based cohort study

OBJECTIVES

To investigate the association between exposure to biologics during pregnancy and serious infections in mothers and infants.

DESIGN

Retrospective cohort study.

SETTING

Population-based.

PARTICIPANTS

Women with one or more autoimmune diseases identified by International Classification of Diseases 9th/10th revision codes in healthcare administrative databases in British Columbia, Canada, who had pregnancies ending in a live or stillbirth between 1 January 2002 and 31 December 2012. Women were defined as exposed if they had at least one biologic prescription during pregnancy, and infants born to these women were considered exposed in utero. Disease-matched women with no biologics prescriptions during pregnancy, and their infants, comprised the unexposed groups.

PRIMARY OUTCOME MEASURES

Serious infections requiring hospitalisation.

RESULTS

Over the 10-year study period, there were 6218 women (8607 pregnancies) who had an autoimmune disease diagnosis, of which 90 women were exposed to biologics during pregnancy, with 100 babies born to these women. Among women exposed to biologics during pregnancy, occurrence of serious postpartum infections were low, ranging from 0% to 5%, depending on concomitant exposures to immunosuppressants. In multivariable models using logistic regression, the OR for the association of biologics exposure with serious maternal postpartum infections was 0.79 (95% CI 0.24 to 2.54). In infants exposed to biologics in utero, occurrence of serious infections during the first year of life ranged from 0% to 7%, depending on concomitant exposures to immunosuppressants in utero. Multivariable models showed no association between biologics exposure in utero and serious infant infections (OR 0.56, 95% CI 0.17 to 1.81).

CONCLUSIONS

These population-based data suggest that the use of biologics by women with autoimmune diseases during pregnancy is not associated with an increased risk of serious infections in mothers, during post partum or in infants during the first year of life.

Association of Prenatal Exposure to Valproate and Other Antiepileptic Drugs With Risk for Attention-Deficit/Hyperactivity Disorder in Offspring

IMPORTANCE

Valproate is an antiepileptic drug (AED) used in the treatment of epilepsy and many other neurological and psychiatric disorders. Its use in pregnancy is associated with increased risks of congenital malformations and adverse neurodevelopment in the offspring and may be associated with an increased risk of attention-deficit/hyperactivity disorder (ADHD).

OBJECTIVE

To determine whether prenatal exposure to valproate and other AEDs is associated with an increased risk of ADHD in the offspring.

DESIGN, SETTING, AND PARTICIPANTS

This was a population-based cohort study of all live-born singleton children in Denmark from January 1, 1997, to December 31, 2011 (N = 913 302). Information on prenatal exposure to AEDs, including valproate, was obtained from the Danish National Prescription Registry and all children with ADHD were identified (children with diagnosed ADHD in the Danish Psychiatric Central Research Register or children who redeemed a prescription for ADHD medication). The cohort was followed up from birth until the day of the ADHD diagnosis, death, emigration, or December 31, 2015, whichever came first. Data were analyzed in September 2018.

EXPOSURES

Maternal use of valproate and other AEDs in pregnancy.

MAIN OUTCOMES AND MEASURES

Cox regression estimates of the hazard ratio of ADHD. Estimates were adjusted for potential confounders.

RESULTS

The cohort included 913 302 children (mean age at end of study, 10.1 years; median age, 9.4 years; interquartile range, 7.2-12.8 years; 468 708 [51.3%] male). A total of 580 were identified as having been exposed to valproate during pregnancy; of them, 49 (8.4%) had ADHD. Among the 912 722 children who were unexposed to valproate, 29 396 (3.2%) had ADHD. Children with prenatal valproate exposure had a 48% increased risk of ADHD (adjusted hazard ratio, 1.48; 95% CI, 1.09-2.00) compared with children with no valproate exposure. The absolute 15-year risk of ADHD was 4.6% (95% CI, 4.5%-4.6%) in children unexposed to valproate and 11.0% (95% CI, 8.2%-14.2%) in children who were exposed to valproate in pregnancy. No associations were found between other AEDs and ADHD.

CONCLUSIONS AND RELEVANCE

Maternal use of valproate, but not other AEDs, during pregnancy was associated with an increased risk of ADHD in the offspring. These findings have important implications for the counseling of women of childbearing potential using valproate.

In utero exposure to antiepileptic drugs is associated with learning disabilities among offspring

OBJECTIVES

In utero exposure to antiepileptic drugs has previously been associated with adverse outcome among offspring, but evidence on longer term milestone development remains limited. We investigated the association between in utero exposure to antiepileptic drugs and learning disabilities in the first year of compulsory education among offspring and assessed which antiepileptic drugs carried the highest risk.

METHODS

This population-based case-cohort study used Danish nationwide register data from 2005 to 2008. Cases were offspring exposed to antiepileptic drugs in utero, and controls were unexposed offspring of mothers previously redeeming antiepileptic drug prescriptions. Offspring were followed from birth until the first year of compulsory education from 2011 to 2015. Learning disabilities were defined as mental retardation, specific developmental disorders, autism spectrum disorders, emotional/behavioural disorders or having special educational needs. Logistic regression was used to compute ORs with 95% CIs adjusted for potential confounding.

RESULTS

Of 117 475 incident singleton births, 636 cases and 434 controls were included (median age: 6.1 years, males: 55.7%). Learning disabilities were identified among 7.1% cases compared with 3.7% for controls. During any trimester, the adjusted OR of the association between in utero exposure to antiepileptic drugs and learning disabilities was 2.20 (95% CI 1.16 to 4.17). Among cases not exposed to polytherapy (n=556), in utero exposure to lamotrigine compared with another antiepileptic drug was associated with the lowest adjusted risk (OR 0.42, 95% CI 0.19 to 0.92), and valproate carried a higher risk (OR 4.67, 95% CI 1.73 to 12.59).

CONCLUSION

In utero exposure to antiepileptic drugs was significantly associated with learning disabilities among offspring. Lamotrigine should preferentially be considered over, for example, valproate if clinically feasible.

Prenatal Exposure to Acetaminophen and Risk for Attention Deficit Hyperactivity Disorder and Autistic Spectrum Disorder: A Systematic Review, Meta-Analysis, and Meta-Regression Analysis of Cohort Studies

Acetaminophen is the analgesic and antipyretic most commonly used during pregnancy. Evidence of neurodisruptive properties is accumulating. Therefore, we sought to evaluate the risk for attention deficit hyperactivity disorder (ADHD) and autistic spectrum disorder (ASD) in the offspring of women exposed to acetaminophen during pregnancy. We searched MEDLINE, Embase, and Cochrane databases for relevant studies up to January 2017. Data were independently extracted and assessed by 2 researchers. Seven eligible retrospective cohorts included 132,738 mother-child pairs, with follow-up periods ranging from 3 to 11 years. The pooled risk ratio for ADHD was 1.34 (95% confidence interval (CI): 1.21, 1.47; I2 = 72%); for ASD, the risk ratio was 1.19 (95% CI: 1.14, 1.25; I2 = 14%), and for hyperactivity symptoms, it was 1.24 (95% CI: 1.04, 1.43; I2 = 93%). In meta-regression analysis, the association between exposure and ADHD increased with the child's age upon follow-up (β = 0.03, 95% CI: 0.00, 0.07) and with the mean duration of exposure (β = 0.00, 95% CI: 0.00, 0.01). The available data is of observational nature only. Studies differed widely in exposure and outcome assessment. Acetaminophen use during pregnancy is associated with an increased risk for ADHD, ASD, and hyperactivity symptoms. These findings are concerning; however, results should be interpreted with caution given that the available evidence consists of observational studies and is susceptible to several potential sources of bias.

Prescribing antibiotics when the stakes are higher — do GPs prescribe less when patients are pregnant? A retrospective observational study

Background

Most oral antibiotics are prescribed by GPs, and they are therefore the most important influencers with regard to improving antibiotic prescription patterns. Although GPs’ prescription patterns in general are well-studied, little is known about antibiotic prescription patterns in pregnancy.

Aim

To study GPs’ antibiotic prescriptions in respiratory tract infections (RTIs) during pregnancy, and assess differences, if any, between pregnant and non-pregnant patients.

Design & setting

Retrospective observational study combining prescription data from the Norwegian Peer Academic Detailing (Rx-PAD) study database, pregnancy data from the Norwegian birth registry, and pharmacy dispension data from the Norwegian Prescription Database (NorPD).

Method

Records of patient contacts with 458 GPs, between December 2004 and February 2007, were screened for RTI episodes. Similar diagnoses were grouped together, as were similar antibiotics. Episodes were categorised according to whether the patient was pregnant or not, and included women aged 16–46 years. Logistic regression models were used to assess odds ratios (ORs), and calculated relative risks (cRRs) were produced. The authors also adjusted for clustering at various levels.

Results

Overall prescription rate for RTI episodes was 30.8% (n = 96 830). The cohort was reduced to include only episodes with women pregnant in the study period (n = 18 890). The antibiotic prescription rate in pregnancy was 25.9% versus 34.2% in the time before and after pregnancy (cRR = 0.66 [95% confidence intervals {CI} = 0.68 to 0.81]).

During pregnancy, 83.0% of the antibiotic prescriptions were picked up at a pharmacy, compared to an 86.6% filling rate in non-pregnant patients. The difference was not significant when adjusting for clustering at the patient level.

Conclusion

Norwegian GPs prescribe fewer antibiotics overall when patients are pregnant and, when they do prescribe, choose more narrow spectrum antibiotics for RTIs. This indicates a possible lower target rate for GP prescriptions to females. A low antibiotic dispension rate during pregnancy may represent a discussion topic in the consultation setting, to address possible reasons and avoid under-treatment.

Maternal hypothyroidism in the perinatal period and childhood asthma in the offspring

BACKGROUND

There is increasing interest in the possible link between maternal hypothyroidism in the perinatal period and childhood asthma risk. We explored this in this study while accounting for the timing of hypothyroidism diagnosis. Further, we evaluated whether the risk was moderated by thyroid hormone treatment during pregnancy.

METHODS

We conducted a population-based cohort study using Danish national registers. All live-born singletons in Denmark from 1998 to 2007 were identified. Maternal hypothyroidism and asthma in the children were defined by data from the Patient Register and Prescription Registry. We estimated incidence rate ratios (IRRs) of asthma among children born to hypothyroid mothers versus children born to mothers with no recorded thyroid dysfunction using Poisson regression models.

RESULTS

Of 595 669 children, 3524 children were born to mothers with hypothyroidism diagnosed before delivery and 4664 diagnosed after delivery. Overall, 48 990 children received treatment for asthma. The IRRs of asthma was 1.16 (95% confidence interval (CI): 1.03-1.30) and 1.12 (95% CI: 1.02-1.24) for children born to mothers with hypothyroidism diagnosed before and after delivery, compared to children born to mothers with no thyroid dysfunction. The highest risk was observed among children born to mothers with hypothyroidism diagnosed before delivery who did not receive thyroid hormone treatment during pregnancy (IRR=1.37, 95% CI: 1.04-1.80).

CONCLUSION

Our findings suggest that maternal hypothyroidism, especially when it is untreated, increases childhood asthma risk. Early detection and appropriate treatment of hypothyroidism in pregnant women may be an area for possible prevention of childhood asthma.

Using Web-Based Questionnaires to Assess Medication Use During Pregnancy: A Validation Study in 2 Prospectively Enrolled Cohorts

Medication use is often underreported in paper-based questionnaires or interviews. Web-based questionnaires may improve recall of medication use, but data on their validity are currently lacking. Participants in the Pregnancy and Infant Development (PRIDE) Study (2014-2016; n = 557) and the Pregnancy Drug Registry (pREGnant) (2015-2016; n = 169) completed a 6-week paper-based medication diary during gestational weeks 19-24 or 26-31. In week 34, they completed a Web-based questionnaire with questions on medication names, time period and frequency of use, and quantity taken. To assess the degree of underreporting, we calculated the questionnaire's sensitivity using the medication diary as the reference standard. Sensitivity was high for many medication groups, including antiepileptic medication (sensitivity (Sn) = 0.96, 95% confidence interval (CI): 0.89, 1.00), antacids (Sn = 0.89, 95% CI: 0.86, 0.93), and iron preparations (Sn = 0.81, 95% CI: 0.64, 0.98). However, medications for short-term use were underreported more frequently, with sensitivities of 0.54 (95% CI: 0.35, 0.72) for antihistamines, 0.63 (95% CI: 0.57, 0.69) for analgesic and antipyretic agents, and 0.57 (95% CI: 0.51, 0.64) for acetaminophen. Shortening the period of time between exposure and questionnaire administration increased sensitivity substantially. In conclusion, underreporting in Web-based questionnaires is limited for many medication groups. In prospective studies, underreporting of medications for short-term use may be reduced by decreasing the interval between consecutive questionnaires.

Agreement Between Maternal Report and Medical Records During Pregnancy: Medications for Rheumatoid Arthritis and Asthma

BACKGROUND

There are limited data regarding the comparability of medication exposure information during pregnancy from maternal report and medical records, including for rheumatoid arthritis and asthma-related medications.

METHODS

This study included pregnant women with rheumatoid arthritis (n = 216) and asthma (n = 172) enrolled in the MothertoBaby Pregnancy Studies (2009-2014). Women reported types and dates of medications used through semi-structured telephone interviews up to three times during pregnancy and once after delivery, and medical records were obtained. We calculated Cohen's kappa coefficients and 95% confidence intervals (CIs) and per cent agreement for agreement between report and records.

RESULTS

For rheumatoid arthritis, prednisone was reported most frequently (53%). During pregnancy, kappa coefficients for rheumatoid arthritis medications ranged from 0.32 (95% CI 0.15, 0.50) for ibuprofen, with 84.3% agreement, to 0.90 (95% CI 0.84, 0.96) for etanercept with 95.4% agreement, and was 0.44 (95% CI 0.33, 0.55) for prednisone, with 71.3% agreement. For asthma, albuterol was reported most frequently (77.9%). During pregnancy, kappa coefficients for asthma medications ranged from 0.21 (95% CI 0.08, 0.35), with 64.5% agreement for albuterol to 0.84 (95% CI 0.71, 0.96) for budesonide/formoterol, with 96.5% agreement. Where kappas for any use during pregnancy were less than excellent (i.e. ≤0.80), medication use was more frequently captured by report than record.

CONCLUSIONS

Agreement was higher for medications typically used continuously than sporadically. Information on medication use from medical records alone may not be adequate when studying the impact of intermittently used medications during pregnancy on perinatal outcomes.

Drug use in pregnant women-a pilot study of the coherence between reported use of drugs and presence of drugs in plasma

Purpose

In Sweden, information on drug use during pregnancy is obtained through an interview and recorded in a standardized medical record at every visit to the antenatal care clinic throughout the pregnancy. Antenatal, delivery, and neonatal records constitute the basis for the Swedish Medical Birth Register (MBR). The purpose of this exploratory study was to investigate the reliability of reported drug use by simultaneous screening for drug substances in the blood stream of the pregnant woman and thereby validate self-reported data in the MBR.

Methods

Plasma samples from 200 women were obtained at gestational weeks 10–12 and 25 and screened for drugs by using ultra-high performance liquid chromatography with time of flight mass spectrometry (UHPLC-TOF-MS). The results from the analysis were then compared to medical records.

Results

At the first sampling occasion, the drugs found by screening had been reported by 86% of the women and on the second sampling, 85.5%. Missed reported information was clearly associated with drugs for occasional use. The most common drugs in plasma taken in early and mid-pregnancy were meclizine and paracetamol. Two types of continuously used drugs, selective serotonin reuptake inhibitors and propranolol, were used. All women using them reported it and the drug screening revealed a 100% coherence.

Conclusions

This study shows good coherence between reported drug intake and the drugs found in plasma samples, which in turn positively validates the MBR.

Prenatal exposure to antipsychotic medication and use of primary health care system in childhood: a population-based cohort study in Denmark

Background

Antipsychotic (AP) medication is increasingly used for many health conditions. Prenatal exposure to AP medication has been associated with several adverse outcomes, but the findings remain inconsistent.

Purpose

We aimed to investigate prenatal exposure to AP medication and the use of primary health care system in childhood.

Subjects and methods

All live-born singletons in Denmark during 1997-2012 were identified in the nationwide Danish National Patient Register and followed until December 31, 2013 (n = 963,010). Information on prenatal exposure to AP medication was obtained from the Danish Register of Medicinal Product Statistics. Contacts to the general practitioner (GP) were used as a proxy for the overall health of the children. Negative binomial regression was used to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for the association between prenatal exposure to AP medication and number and type of GP contacts, excluding routine well-child visits and vaccinations. The models were adjusted for sex and birth date of the child, maternal age, parity, cohabitation status, income, education, smoking status, diagnosis of substance abuse, severe psychiatric disorder, depression and epilepsy as well as the use of antiepileptic drugs, antidepressants, benzodiazepines and insulin.

Results

The prenatally AP-exposed children had 7% more GP contacts than unexposed children, IRR: 1.07 (95% CI: 1.03, 1.11). The association was slightly stronger among children of mothers with no diagnosis of severe psychiatric disorder (IRR: 1.08, 95% CI: 1.04-1.13) than among children of mothers with severe psychiatric disorder (IRR: 1.03, 95% CI: 0.96-1.11), but the difference was not statistically significant. We found no difference between prenatally AP-exposed children and their unexposed siblings, IRR: 1.00 (95% CI: 0.97-1.04) for total contacts.

Conclusion

Children of women using AP medication in pregnancy had more GP contacts in childhood than children of mothers not using AP medication. However, this might be explained by confounding from maternal behavior and mental illness.