Neonatal phototherapy and risk of epilepsy-A Danish population based study.

To evaluate the risk of epilepsy in children who received neonatal phototherapy. A cohort of live singletons born at a Danish hospital (2002-2016) with a gestational age ≥ 35 weeks. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of epilepsy in children treated with neonatal phototherapy compared to children not treated with neonatal phototherapy in the general population, and in a subpopulation of children who had serum bilirubin measurement. Adjusted HRs (aHR) were computed using multivariable and propensity score matching models to take maternal and neonatal factors into consideration. Children were followed from day 29 after birth to diagnosis of epilepsy, death, emigration, or December 31, 2016. Among 65,365 children, 958 (1.5%) received neonatal phototherapy. Seven children (incidence rates (IRs): 10.8 /10,000 person-years) who received neonatal phototherapy and 354 children (IR: 7.7) who did not receive neonatal phototherapy were diagnosed with epilepsy. Neonatal phototherapy was not associated with an increased risk of epilepsy using the multivariable (aHR 0.95, 95% CI: 0.43-2.09) and propensity score matched (aHR 0.94, 95% CI: 0.39-2.28) models. In the subpopulation of 9,378 children with bilirubin measurement, 928 (9.9%) received neonatal phototherapy. In the analysis of the subpopulation in which bilirubin level and age at the time of bilirubin measurement were further taking into consideration, neonatal phototherapy was not associated with an increased risk of epilepsy using the multivariable (aHR 1.26, 95% CI: 0.54-2.97) and propensity score matched (aHR 1.24, 95% CI: 0.47-3.25) models,Conclusions: Neonatal phototherapy was not associated with an increased risk of epilepsy after taking maternal and neonatal factors into consideration. What is known: • A few studies have suggested that neonatal phototherapy for hyperbilirubinemia may increase the risk of childhood epilepsy. • Whether the observed associations contribute to hyperbilirubinemia, phototherapy, or underlying factors requires further investigation. What is new: • This study revealed no increased risk of epilepsy in children treated with neonatal phototherapy compared to children not treated with phototherapy after taking maternal and neonatal factors into consideration. • After further taking bilirubin level and age at the time of bilirubin measurement into consideration, neonatal phototherapy was not associated with an increased risk of epilepsy.

Socioeconomic differences in use of antiseizure medication in pregnancies with maternal epilepsy: A population-based study from Nordic universal health care systems.

OBJECTIVE: Research points to disparities in disease burden and access to medical care in epilepsy. We studied the association between socioeconomic status (SES) and antiseizure medication (ASM) use in pregnancies with maternal epilepsy. METHODS: We conducted a cross-sectional study consisting of 21 130 pregnancies with maternal epilepsy identified from Nordic registers during 2006-2017. SES indicators included cohabitation status, migrant background, educational attainment, and household income. Main outcomes were the proportion and patterns of ASM use from 90 days before pregnancy to birth. We applied multiple imputation to handle SES variables with 2%-4% missingness. We estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) using modified Poisson regression with the highest SES category as reference. RESULTS: Mothers with the highest education and the highest income quintile used ASMs least frequently (56% and 53%, respectively). We observed increased risks of ASM discontinuation prior to or during the first trimester for low SES. The risk estimates varied depending on the SES indicator from aRR = 1.27 for low income (95% CI: 1.03-1.57) to aRR = 1.66 for low education (95% CI: 1.30-2.13). Migrant background was associated with ASM initiation after the first trimester (aRR 2.17; 95% CI 1.88-2.52). Low education was associated with the use of valproate during pregnancy in monotherapy (aRR 1.70; 95% CI 1.29-2.24) and in polytherapy (aRR 2.65; 95% CI 1.66-4.21). Low education was also associated with a 37% to 39% increased risk of switching from one ASM to another depending on the ASM used. For the other SES indicators, aRRs of switching varied from 1.16 (foreign origin; 95% CI 1.08-1.26) to 1.26 (not married or cohabiting; 95% CI 1.17-1.36). SIGNIFICANCE: Low SES was associated with riskier patterns of ASM use: discontinuation, late initiation, and switching during pregnancy. These findings may reflect unplanned pregnancies, disparities in access to preconception counseling, and suboptimal care.

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.

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.

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.

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.

Neonatal Phototherapy and Clinical Characteristics: The Danish National Patient Registry 2000-2016.

Purpose: Phototherapy is the standard treatment for neonatal hyperbilirubinemia. It is important to collect data on phototherapy to support research related to the efficacy and safety of phototherapy. We explored the registration of phototherapy in the Danish National Patient Registry (DNPR) and the clinical characteristics of neonates treated with phototherapy. Methods: We identified children born alive in Denmark from 1 January 2000 through 30 November 2016 from the DNPR (N=1,044,502). We calculated the proportion of children registered that received phototherapy during the neonatal period and examined temporal trends, both nationwide and at the level of individual hospitals. In a sub-cohort of children born at Aarhus University Hospital (AUH) in 2002-2016 (N=71,781), we analyzed the proportions of children registered that received phototherapy, according to sex, gestational age, birth weight, and neonatal characteristics, like Apgar score, birth asphyxia, and infections. Results: We identified 11,295 (1.1%) registered that received phototherapy. The proportions of children registered that received phototherapy differed among hospitals (range: 0 to 4.1%). Nationwide registration was low during the study period, but it increased to 1.8% in 2016. For the AUH sub-cohort the proportion of children registered with phototherapy averaged 4.4% (N=3182, range:3.9-5.1%). The proportion of children registered with phototherapy was inversely correlated with gestational age and birth weight, and positively correlated with neonatal characteristics, including low Apgar score, birth asphyxia, and infections. Conclusion: Phototherapy was under-reported in the DNPR and the proportions of children registered that received phototherapy differed among hospitals. The non-compulsory policy for reporting treatment and care in hospitals to the DNPR might explain the variation. The most consistent reporting was observed among children born in an university hospital, where 4.4% of children registered that received phototherapy, and phototherapy was inversely associated with gestational age, birth weight, and positively associated with clinical characteristics like birth asphyxia, and infections.

Estimates of epilepsy prevalence, psychiatric co-morbidity and cost.

PURPOSE: This study estimated epilepsy prevalence, psychiatric co-morbidity and annual costs associated with epilepsy. METHODS: We used Danish national health registers to identify persons diagnosed with epilepsy and psychiatric disorders, and persons using antiseizure medication and persons using drugs for psychiatric disorders. We calculated the prevalence of epilepsy and co-morbid psychiatric disorders in Denmark on December 31, 2016, using information on epilepsy and psychiatric disorders based on combinations of hospital contacts and use of antiseizure and psychoactive medication. Further, direct and indirect annual costs associated with epilepsy were calculated using individual-level data from a range of socioeconomic registers. RESULTS: There were 5,044,367 persons alive and living in Denmark on December 31, 2016, including 33,628 persons with at least one hospital contact with epilepsy in the previous five years (epilepsy prevalence 0.67% (0.69% males; 0.65% females)). Among these persons with epilepsy, we identified 12,562 (37.4%) persons with a psychiatric disorder or use of drugs used for psychiatric disorders as compared with 801,052 (15.9%) persons in the general population. The estimated total annual individual net costs associated with epilepsy was €30,683. Compared with prevalence estimates on December 31, 2006, the prevalence of epilepsy on December 31, 2016, was slightly higher in the older population and slightly lower in children CONCLUSIONS: Population estimates from national registers provide epilepsy prevalence estimates of approximately 0.6-0.7% - similar to previous reviews of epilepsy prevalence. In addition, the national sample allowed idenitfication of high prevalence of psychiatric disorders and high societal costs associated with epielspy.

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.

Folic Acid and Risk of Preterm Birth, Preeclampsia, and Fetal Growth Restriction Among Women With Epilepsy: A Prospective Cohort Study.

BACKGROUND AND OBJECTIVES: Women with epilepsy treated with antiseizure medication (ASM) have increased risk of pregnancy complications including preterm birth, fetal growth restriction, and preeclampsia. We aimed to investigate whether folic acid supplementation is associated with these pregnancy complications in women with epilepsy using ASM. METHODS: Singleton pregnancies in the prospective Norwegian Mother and Child Cohort Study (MoBa) (1999-2008) were included. Information on maternal epilepsy, ASM, folic acid supplementation, and pregnancy outcomes was obtained from the MoBa questionnaires and the Norwegian Medical Birth Registry. The main exposure, periconceptional folic acid supplementation, was defined as intake between 4 weeks before pregnancy and 12 weeks into pregnancy, retrospectively collected by recall of the mothers in weeks 17-19. The primary outcomes were preterm birth (gestational age <37 weeks at birth), small for gestational age (SGA), and preeclampsia. RESULTS: The study included 100,105 pregnancies: 99,431 without maternal epilepsy, 316 with maternal epilepsy and ASM exposure in pregnancy, and 358 with untreated maternal epilepsy. Among ASM-treated women with epilepsy, the risk of preterm birth was higher in those who did not use periconceptional folic acid (n = 64) compared with those who did (n = 245, the reference) (adjusted odds ratio [aOR] 3.3, 95% CI 1.2-9.2), while the risk of preterm birth among the reference was similar to the risk among women without epilepsy using folic acid periconceptionally (aOR 0.9, 95% CI 0.5-1.6). ASM-treated women with epilepsy starting folic acid after the first trimester had a higher risk compared with women without epilepsy with similar timing of folic acid (aOR 2.6, 95% CI 1.1-6.5), and even higher if not using folic acid (aOR 9.4, 95% CI 2.6-34.8). Folic acid was not associated with risk of preterm birth among women with epilepsy without ASM or among women without epilepsy. Folic acid was not associated with risk of preeclampsia or SGA among women with epilepsy. DISCUSSION: In women with epilepsy using ASM, periconceptional folic acid was associated with a lower risk of preterm birth. This finding supports the recommendation that ASM-treated women with epilepsy of childbearing potential should use folic acid supplementation on a regular basis. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for women with epilepsy using ASM, periconceptional folic acid supplementation decreases the risk of preterm birth.

Importance of Reporting Complete Procedures of Identifying Patients from the Danish National Patient Registry: The Case of Neonatal Jaundice and Epilepsy.

Objective: The Danish National Patient Registry (DNPR) is a valuable resource for medical and epidemiological Research. However, not all research articles fully described procedures they used to identify events. In this study, we compared two approaches in identifying persons with a disease diagnosis using neonatal jaundice and epilepsy as examples. Methods: A cohort of singletons born alive between the 1st January 1997 and the 30th November 2016 in Denmark was used for this purpose. Diagnostic information for a hospital contact in the registry included a primary diagnosis, secondary diagnoses, referral diagnoses, and additional information to a diagnosis (associated diagnoses), if any. Approach 1 identified patients of interest by considering all diagnostic information with exclusion of referral diagnoses only. Approach 2 identified patients of interest by additionally excluding diagnoses from a hospital contact that were coded with Z00 - Z99 of ICD-10 (for health service on examination and reproduction, etc.) as the main reason of the hospital contact. We presented the proportion of people with a diagnosis of neonatal jaundice and epilepsy by the two approaches and explored the potential explanations for the difference. Results: For the example of neonatal jaundice, the study population included N=1,186,683 persons. The proportion of children with a diagnosis of neonatal jaundice was 5.5% (n=66,736) by approach 1 and 3.9% (n=45,928) by approach 2. For the example of epilepsy, the study population included N=1,183,273 persons. The proportion of children with a diagnosis of epilepsy were 1.2% (n=14,604) by approach 1 and 0.9% (n=10,441) by approach 2. Discussion: This study demonstrated that the two approaches identified different proportion of persons with a diagnosis of neonatal jaundice and epilepsy. We advocated researchers report complete procedures of identifying patients for making research findings reproducible and comparable.

Perinatal adversities and risk of epilepsy after traumatic brain injury: A Danish nationwide cohort study.

OBJECTIVES: Traumatic brain injury (TBI) and perinatal adversities such as low gestational age at birth, low birth weight, low Apgar, and being born small for gestational age are well-established risk factors for epilepsy. We examined whether perinatal adversities modified the risk of epilepsy after TBI in a nationwide cohort study of Danish singletons born from 1982 to 2011. MATERIALS AND METHODS: We categorized perinatal adversities as a composite measure of preterm delivery, low birth weight, low Apgar score, or being born small for gestational age. Cox regression and competing risk regression were used to estimate the risk of epilepsy after TBI according to such perinatal adversities. The study included 1,715,095 singletons (51.1% males). The mean age at end of follow-up was 19.3 years (Interquartile range [IQR] = 12.1-26.3). During follow-up, 85,636 persons (58.2% males) sustained a TBI and 18,064 developed epilepsy (50.7% males), of whom 1329 persons had a preceding TBI. RESULTS: The hazard ratio (HR) of epilepsy in persons with perinatal adversities was 1.19 (95% confidence interval [CI] 1.15-1.24), compared to persons without. The HR of epilepsy in persons with TBI was 2.31 (95% CI 2.18-2.45) compared to persons without TBI, but this risk was not modified by perinatal adversities (p = 0.2460). CONCLUSIONS: Perinatal adversities and TBI both increased the risk of epilepsy, but the risk of epilepsy after TBI was not modified by these perinatal adversities.

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.

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.

Prenatal exposure to valproate and risk of congenital malformations-Could we have known earlier?-A population-based cohort study.

OBJECTIVE: Prenatal exposure to the antiseizure medication (ASM) valproate is associated with an increased risk of congenital malformations, but warnings against the use of valproate in pregnancy were not issued until 2009. The objective was to study how early administrative health registers could have identified the teratogenic risk associated with valproate. METHODS: This was a population-based cohort study of individual-linked data from Danish health care and socioeconomic registers including children born in Denmark between January 1, 1997 and December 31, 2014. Information on ASM use, including valproate, in pregnancy was obtained from the Danish National Prescription Registry. Children identified with major congenital malformations from the Danish National Patient Register and the Danish Register of Causes of Death were included. Using logistic regression models, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for major congenital malformations during the first year of life in children with and without prenatal exposure to ASMs adjusted for potential confounders. RESULTS: Among the 895 507 children (males, 51.3%), 31 790 (3.6%) were diagnosed with a major congenital malformation in the first year of life. In the analyses including children born in 1997, the risk of major congenital malformations among children prenatally exposed to valproate compared with children not exposed to ASMs was increased by a fully adjusted OR (aOR) of 3.95 (95% CI = 1.65-9.47). With the addition of data from the following years, the teratogenic effect of valproate was further substantiated, as the precision of the estimate improved (1997-2014: aOR = 2.44, 95% CI = 1.80-3.30). SIGNIFICANCE: Using Danish health care data, we were able to identify a teratogenic risk associated with prenatal valproate exposure in children born in 1997, which is much earlier than prospective clinical cohorts. Health registry data represent an important tool for early identification of risk associated with drugs in pregnancy.

Exploring the prevalence and profile of epilepsy across Europe using a standard retrospective chart review: Challenges and opportunities.

OBJECTIVE: This study aimed to determine the prevalence of epilepsy in four European countries (Austria, Denmark, Ireland, and Romania) employing a standard methodology. The study was conducted under the auspices of ESBACE (European Study on the Burden and Care of Epilepsy). METHODS: All hospitals and general practitioners serving a region of at least 50 000 persons in each country were asked to identify patients living in the region who had a diagnosis of epilepsy or experienced a single unprovoked seizure. Medical records were accessed, where available, to complete a standardized case report form. Data were sought on seizure frequency, seizure type, investigations, etiology, comorbidities, and use of antiseizure medication. Cases were validated in each country, and the degree of certainty was graded as definite, probable, or suspect cases. RESULTS: From a total population of 237 757 in the four countries, 1988 (.8%) patients were identified as potential cases of epilepsy. Due to legal and ethical issues in the individual countries, medical records were available for only 1208 patients, and among these, 113 had insufficient clinical information. The remaining 1095 cases were classified as either definite (n = 706, 64.5%), probable (n = 191, 17.4%), suspect (n = 153, 14.0%), or not epilepsy (n = 45, 4.1%). SIGNIFICANCE: Although a precise prevalence estimate could not be generated from these data, the study found a high validity of epilepsy classification among evaluated cases (95.9%). More generally, this study highlights the significant challenges facing epidemiological research methodologies that are reliant on patient consent and retrospective chart review, largely due to the introduction of data protection legislation during the study period. Documentation of the epilepsy diagnosis was, in some cases, relatively low, indicating a need for improved guidelines for assessment, follow-up, and documentation. This study highlights the need to address the concerns and requirements of recruitment sites to engage in epidemiological research.

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.