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.

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.

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.

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.

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.

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.

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 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.

Accidental deaths in young people with epilepsy and psychiatric comorbidity-A Danish nationwide cohort study.

OBJECTIVE: The objective of this study was to investigate the accident-related mortality among people younger than 55 years of age with epilepsy compared with the general population and to study how psychiatric comorbidity influences this risk. METHODS: This is a population-based cohort study of individuals born in Denmark between 1960 and 2015 (n = 3, 665 616). Persons diagnosed with epilepsy and psychiatric disorders were identified in the Danish National Patient Register and the Danish Central Psychiatric Central Register. We estimated the hazard ratio (HR) with 95% confidence intervals (CIs) of accidental death in people with epilepsy compared with persons without epilepsy. RESULTS: We identified 61 330 persons (1.7%) diagnosed with epilepsy. Median age at end of follow-up was 27.8 years. In people with epilepsy, 5253 died during follow-up, 480 (9%) of whom died from accidents. Among people without epilepsy, 52 588 died during follow-up, of whom 1280 (2.4%) died from accidents. People with epilepsy had a 3.7-fold (95% CI 3.4-4.1) increased risk of accidental death compared with persons without epilepsy. When we adjusted for psychiatric disorders, the risk remained significantly elevated in people with epilepsy compared to people without epilepsy (adjusted HR [aHR] 2.44, 95% CI 2.22-2.69). When stratifying the analyses on epilepsy and psychiatric disorders, people with epilepsy and psychiatric disorders had an aHR of 4.95 (95% CI 3.82-6.41) when compared with persons without epilepsy and psychiatric disorders. SIGNIFICANCE: The risk of accidental death was increased in people with epilepsy and was particularly high among people with epilepsy with psychiatric comorbidity. The findings highlight the need for awareness and prevention strategies in people with epilepsy, especially in people with comorbid psychiatric disorders.

Antidepressant use during pregnancy and risk of congenital heart defects: A case-time-control study.

PURPOSE: We estimated the association between maternal antidepressant (AD) use in early pregnancy and risk of congenital heart defects. METHODS: We applied a case-time-control design with the aim of controlling for confounding from time-invariant factors and compared the results of the design to results from a cohort design in a population of 792 685 singletons born alive in Denmark during 1995-2008. In the case-time-control design, we identified children diagnosed with a congenital heart defect in the first 5 years of life (cases) and compared maternal AD use in the risk period (the first 3 months of pregnancy) and the reference period (gestational months 5-7). A nondiseased control group was included to adjust for time trends of exposure. In the cohort design, we identified children whose mothers redeemed at least one AD prescription in the first 3 months of pregnancy (the exposed) and two other groups including the unexposed children with maternal AD prescriptions in the 12 months before pregnancy. We applied conditional logistic regression and logistic regression to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The case-time-control OR for any congenital heart defect was 1.03 (95% CI, 0.61-1.73), which was similar to the OR (1.09, 95% CI, 0.88-1.35) from the cohort design when we compared the exposed children with the unexposed children with maternal AD use before pregnancy. CONCLUSIONS: The case-time-control design provided results similar to the cohort design when the cohort design had a better confounder control strategy. We discussed the strengths and drawbacks of case-time-control design.

Prenatal exposure to antidepressants and risk of epilepsy in childhood.

PURPOSE: This study aimed to estimate the association between prenatal exposure to antidepressants and risk of epilepsy in childhood, taking maternal depression into account. METHODS: We conducted a population-based cohort study including all Danish singletons born alive between 1997 and 2008 (n = 734 237). Information on antidepressant medication and diagnosis of depression and epilepsy was obtained from Danish National Registers. The exposed group comprised children of mothers who used antidepressants from 30 days before pregnancy until the date of birth. The reference group comprised children of mothers who used no antidepressants from 6 months before pregnancy to birth. We estimated the hazard ratios (HR) of epilepsy and 95% confidence intervals (CI) using Cox proportional hazard models. RESULTS: We identified 12 438 (1.7%) children exposed to antidepressants during pregnancy (including 30 days before pregnancy) and 5829 (0.8%) children diagnosed with epilepsy in the follow-up time (mean: 6.7 years). Children exposed to antidepressants during pregnancy had a 27% higher risk of epilepsy (aHR: 1.27; 95%CI: 1.05-1.54) than children in the reference group. The estimate of this association was 1.71 (95%CI: 1.10-2.66) if their mothers also had a registry-based hospital diagnosis of depression in the 6 months before pregnancy or during pregnancy and 1.14 (95%CI: 0.91-1.43) if their mothers had no registry-based hospital diagnosis of depression. Children of mothers who used antidepressants from 2 to 6 months before pregnancy (but not during pregnancy) had an increased risk of epilepsy (aHR: 1.36; 95%CI: 1.07-1.73). CONCLUSIONS: Antidepressant use during pregnancy was associated with a higher risk of epilepsy among children whose mothers had also a registry-based hospital diagnosis of depression during pregnancy. Copyright © 2016 John Wiley & Sons, Ltd.

Trimethoprim use before pregnancy and risk of congenital malformation: reanalyzed using a case-crossover design and a case-time-control design.

PURPOSE: Studies on the safety of drugs used during pregnancy are necessary and important but prone to bias. Using cases as their own controls can reduce bias. We used a case-crossover design and a case-time-control design to estimate the risk of congenital malformation (CM) for children born to mothers who redeemed a trimethoprim prescription shortly before pregnancy. METHODS: The study was based on all live born singletons (N = 685 600) in Denmark whose mothers had available information on prescriptions in the Danish National Prescription Registry between 1996 and 2008. We defined 1-3 months before pregnancy as a potential risk period and 13-15 months before pregnancy as a reference period. Two other reference periods were used (7-9 months before pregnancy and months 4-6 of pregnancy). The case-crossover design is dependent on the assumption of a stable trimethoprim prescription over the study period in the source population. To estimate the trend of trimethoprim prescriptions, we used a control group comprising children without CMs. RESULTS: Both study designs showed children had a higher risk of overall CM [odds ratio of 1.66, 95% confidence interval (CI): 1.10-2.53 and 1.50, 95%CI: 0.66-3.38, respectively] if their mothers had a trimethoprim prescription in the 3 months before pregnancy and subtypes of CM for example in the musculoskeletal system, which were consistent to the previous findings from a cohort study. CONCLUSIONS: This study corroborates that trimethoprim is a potential teratogen when used 3 months before pregnancy and demonstrates the value of case-only approaches for studying, for example, adverse effects of antibiotics in reproductive epidemiology.

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.

Cancer risks in parents who had a child with a congenital malformation.

Cancer risk in parents may be related to congenital malformations (CMs) in their children if they share genetic susceptibility or environmental exposure that may be teratogenic and carcinogenic. We conducted a population-based cohort study based on Danish register data. We identified 795,607 mothers and 781,424 fathers who had all their children between 1977 and 2007 in Denmark. Information on CM was obtained from the Danish Hospital Registry and information on cancer was obtained from the Danish Cancer Registry. Parents were followed from the birth of their first child until the diagnosis of cancer, death, emigration, or December 31, 2007. We used Cox regression models to estimate hazard ratios (HRs) for cancer including cancer in specific organs in mothers and fathers. Overall, 75,701 (9.5%) mothers and 72,724 (9.3%) fathers had at least one child diagnosed with CMs within the first year of life. Neither mothers (HR=1.04; 95% CI: 0.99-1.04) nor fathers (HR=1.03; 95% CI: 0.98-1.09) who had a child with a CM had a higher overall risk of cancer. Mothers (HR=0.76, 95% CI: 0.58-1.00) or fathers (HR=0.89, 95% CI: 0.66-1.19) who had a child with a chromosomal malformation had a lower overall cancer risk. The findings also showed a higher risk for some specific types of cancer in parents who had children with a CM in the specific system. Some, or perhaps all, of these findings may be due to chance caused by multiple comparisons. We present all results on paper or online to provide clues for further research and to avoid publication bias.

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.

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.