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.

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.

Does maternal genetic liability to folate deficiency influence the risk of antiseizure medication-associated language impairment and autistic traits in children of women with epilepsy?

BACKGROUND: Prenatal exposure to antiseizure medication (ASM) may lead to low plasma folate concentrations and is associated with impaired neurodevelopment. OBJECTIVES: To examine whether maternal genetic liability to folate deficiency interacts with ASM-associated risk of language impairment and autistic traits in children of women with epilepsy. METHODS: We included children of women with and without epilepsy and with available genetic data enrolled in the Norwegian Mother, Father, and Child Cohort Study. Information on ASM use, folic acid supplement use and dose, dietary folate intake, child autistic traits, and child language impairment was obtained from parent-reported questionnaires. Using logistic regression, we examined the interaction between prenatal ASM exposure and maternal genetic liability to folate deficiency expressed as polygenic risk score of low folate concentrations or maternal rs1801133 genotype (CC or CT/TT) on risk of language impairment or autistic traits. RESULTS: We included 96 children of women with ASM-treated epilepsy, 131 children of women with ASM-untreated epilepsy, and 37,249 children of women without epilepsy. The polygenic risk score of low folate concentrations did not interact with the ASM-associated risk of language impairment or autistic traits in ASM-exposed children of women with epilepsy compared with ASM-unexposed children aged 1.5-8 y. ASM-exposed children had increased risk of adverse neurodevelopment regardless of maternal rs1801133 genotype {adjusted odds ratio [aOR] for language impairment aged 8 y was 2.88 [95% confidence interval (CI): 1.00, 8.26] if CC and aOR 2.88 [95% CI: 1.10, 7.53] if CT/TT genotypes}. In children of women without epilepsy aged 3 y, those with maternal rs1801133 CT/TT compared with CC genotype had increased risk of language impairment (aOR: 1.18; 95% CI: 1.05, 1.34). CONCLUSIONS: In this cohort of pregnant women reporting widespread use of folic acid supplements, maternal genetic liability to folate deficiency did not significantly influence the ASM-associated risk of impaired neurodevelopment.

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.

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.

Plasma unmetabolized folic acid in pregnancy and risk of autistic traits and language impairment in antiseizure medication-exposed children of women with epilepsy.

BACKGROUND: Fetal exposure to unmetabolized folic acid (UMFA) during pregnancy may be associated with adverse neurodevelopment. Antiseizure medication (ASM) may interact with folate metabolism. Women with epilepsy using ASM are often recommended high-dose folic acid supplement use during pregnancy. OBJECTIVES: The aim was to determine the association between UMFA concentrations in pregnant women with epilepsy using ASM and risk of autistic traits or language impairment in their children aged 1.5-8 y. METHODS: We included children of women with epilepsy using ASM and with plasma UMFA measurement enrolled in the Norwegian Mother, Father, and Child Cohort Study (MoBa). Data on ASM use, folic acid supplement use, autistic traits, and language impairment were obtained from parent-reported questionnaires during pregnancy and when the child was 1.5, 3, 5, and 8 y old. Plasma UMFA concentrations were measured during gestational weeks 17-19. RESULTS: A total of 227 ASM-exposed children of 203 women with epilepsy were included. Response rates at ages 1.5, 3, 5, and 8 y were 67% (n = 151), 54% (n = 122), 36% (n = 82), and 37% (n = 85), respectively. For 208 (94%) children, the mother reported intake of folic acid supplement. There was no association between UMFA concentrations and autistic traits score in the adjusted multiple regression analyses at age 3 y (unstandardized B: -0.01; 95% CI: -0.03, 0.004) or 8 y (unstandardized B: 0.01; 95% CI: -0.02, 0.03). Children exposed to UMFA had no increased risk of autistic traits at age 3 y [adjusted OR (aOR): 0.98; 95% CI: 0.2, 4.2] or 8 y (aOR: 0.1; 95% CI: 0.01, 1.4) compared with unexposed children. We found no association between UMFA concentrations and language impairment in children aged 1.5-8 y. CONCLUSIONS: Our findings do not support any adverse neurodevelopmental effects of UMFA exposure in utero in children of women with epilepsy using ASM.

Vitamin B status and association with antiseizure medication in pregnant women with epilepsy.

OBJECTIVE: Antiseizure medication (ASM) use interacts with vitamin B status in nonpregnant epilepsy populations. We aimed to examine the association between ASM and vitamin B status in pregnant women with epilepsy. METHODS: We performed a cross-sectional study of pregnancies in women with epilepsy enrolled in the Norwegian Mother, Father and Child Cohort Study from 1999 to 2008. Data on ASM and vitamin supplement use were collected from questionnaires. We analyzed maternal plasma concentrations of ASM and metabolites of folate, including unmetabolized folic acid (UMFA), riboflavin (vitamin B2), pyridoxine (vitamin B6), and niacin (vitamin B3) during gestational weeks 17-19. RESULTS: We included 227 singleton pregnancies exposed to ASM with available plasma samples (median maternal age 29 years, range 18 to 41 years). From the preconception period to gestational week 20, any supplement of folic acid was reported in 208 of pregnancies (94%), riboflavin in 72 (33%), pyridoxine in 77 (35%), and niacin in 45 (20%). High ASM concentrations correlated with high concentrations of UMFA and inactive folate metabolites, and with low concentrations of riboflavin and metabolically active pyridoxine. There was no association between ASM and niacin status. SIGNIFICANCE: ASM concentrations during pregnancy were associated with vitamin B status in pregnant women with epilepsy. Additional studies are needed to determine the clinical impact of these findings, and to define the optimal vitamin doses that should be recommended to improve pregnancy outcomes.

Maternal complications in pregnancy and childbirth for women with epilepsy: Time trends in a nationwide cohort.

OBJECTIVE: Obstetric trends show changes in complication rates and maternal characteristics such as caesarean section, induced labour, and maternal age. To what degree such general time trends and changing patterns of antiepileptic drug use influence pregnancies of women with epilepsy (WWE) is unknown. Our aim was to describe changes in maternal characteristics and obstetric complications in WWE over time, and to assess changes in complication risks in WWE relative to women without epilepsy. METHODS: This was a nationwide cohort study of all first births in the Medical Birth Registry of Norway, 1999-2016. We estimated maternal characteristics, complication rates, and risks for WWE compared to women without epilepsy. Main maternal outcome measures were hypertensive disorders, bleeding in pregnancy, induction of labour, caesarean section, postpartum hemorrhage, preterm birth, small for gestational age, and epidural analgesia. Time trends were analyzed by logistic regression and comparisons made with interaction analyses. RESULTS: 426 347 first births were analyzed, and 3077 (0.7%) women had epilepsy. In WWE there was an increase in proportions of induced labour (p<0.005) and use of epidural analgesia (p<0.005), and a reduction in mild preeclampsia (p = 0.006). However, the risk of these outcomes did not change over time. Only the risk of severe preeclampsia increased significantly over time relative to women without epilepsy (p = 0.006). In WWE, folic acid supplementation increased significantly over time (p<0.005), and there was a decrease in smoking during pregnancy (p<0.005), but these changes were less pronounced than for women without epilepsy (p<0.005). CONCLUSIONS: During 1999-2016 there were important changes in maternal characteristics and complication rates among WWE. However, outcome risks for WWE relative to women without epilepsy did not change despite changes in antiepileptic drug use patterns. The relative risk of severe preeclampsia increased in women with epilepsy.

Verbal abilities in children of mothers with epilepsy: Association to maternal folate status.

OBJECTIVE: To examine the effect of maternal folic acid supplementation and maternal plasma folate and antiepileptic drug (AED) concentrations on language delay in AED-exposed children of mothers with epilepsy. METHODS: Children of mothers with and without epilepsy enrolled from 1999 to 2008 in the Norwegian Mother and Child Cohort study were included. Information on medical history, AED use, and folic acid supplementation during pregnancy was collected from parent-completed questionnaires. Maternal plasma folate and maternal plasma and umbilical cord AED concentrations were measured in blood samples from gestational weeks 17 to 19 and immediately after birth, respectively. Language development at 18 and 36 months was evaluated by the Ages and Stages Questionnaires. RESULTS: A total of 335 AED-exposed children of mothers with epilepsy and 104,222 children of mothers without epilepsy were surveyed. For those with no maternal periconceptional folic acid supplementation, the fully adjusted odds ratio (OR) for language delay in AED-exposed children compared to the controls at 18 months was 3.9 (95% confidence interval [CI] 1.9-7.8, p < 0.001) and at 36 months was 4.7 (95% CI 2.0-10.6, p < 0.001). When folic supplementation was used, the corresponding ORs for language delay were 1.7 (95% CI 1.2-2.6, p = 0.01) and 1.7 (95% CI 0.9-3.2, p = 0.13), respectively. The positive effect of folic acid supplement use on language delay in AED-exposed children was significant only when supplement was used in the period from 4 weeks before the pregnancy and until the end of the first trimester. CONCLUSION: Folic acid use early in pregnancy may have a preventive effect on language delay associated with in utero AED exposure.

Association of Folic Acid Supplementation During Pregnancy With the Risk of Autistic Traits in Children Exposed to Antiepileptic Drugs In Utero.

Importance: Strategies to prevent autism in children exposed to antiepileptic drugs (AEDs) during pregnancy are important. Objective: To explore whether folic acid supplementation and folate status in pregnancy are associated with reduced risk of autistic traits owing to in utero AED exposure. Design, Setting, and Participants: The population-based, prospective Norwegian Mother and Child Cohort Study approached Norwegian-speaking women attending routine ultrasonographic examinations from June 1999 through December 31, 2008 (163 844 of 277 702 women refused). No exclusion criteria were applied beyond language. Questionnaires during and after pregnancy, analysis of blood samples, and linkage to the Medical Birth Registry of Norway were performed. Children aged 18 to 36 months of women with available information on use of AEDs and of folic acid supplementation (n = 104 946) were included in the analysis from March 1, 2016, through June 13, 2017. Exposures: Maternal folic acid supplementation 4 weeks before to 12 weeks after conception. Plasma folate concentration was analyzed at gestational weeks 17 to 19. Main Outcomes and Measures: Autistic traits were evaluated using the Modified Checklist for Autism in Toddlers and Social Communication Questionnaire. Odds ratios (ORs) for autistic traits in children by maternal use vs nonuse of folic acid supplements were adjusted for maternal health and socioeconomic factors. Folate concentrations and folic acid doses were associated with the degree of autistic traits. Results: The overall mean (SD) age of the 104 946 mothers of participating children was 29.8 (4.6) years, with complete information available for analysis in 103 868. Mean (SD) age of women with epilepsy who received AED treatment was 29.4 (4.9); women with epilepsy who did not receive AED treatment, 29.1 (4.9); and without epilepsy, 29.8 (4.6) years. In the 335 children exposed to AEDs, the risk for autistic traits was significantly higher at 18 months of age (adjusted OR [AOR], 5.9; 95% CI, 2.2-15.8) and 36 months of age (AOR, 7.9; 95% CI, 2.5-24.9) when their mothers had not used folic acid supplements compared with children of mothers who had used supplements. Among women without epilepsy, the corresponding risks were lower at 18 months of age (AOR, 1.3; 95% CI, 1.2-1.4) and 36 months of age (AOR, 1.7; 95% CI, 1.5-1.9); among the 389 children of women with untreated epilepsy, the corresponding risks were not significant at 18 months of age (AOR, 1.0; 95% CI, 0.4-3.0) and 36 months of age (AOR, 2.5; 95% CI, 0.4-16.6). Degree of autistic traits was inversely associated with maternal plasma folate concentrations (ß = -0.3; P = .03) and folic acid doses (ß = -0.5; P < .001). Concentrations of AEDs were not associated with the degree of autistic traits. Conclusions and Relevance: Risk of autistic traits in children exposed to AEDs in utero may be mitigated by periconceptional folic acid supplementation and folate status. Fertile women using AEDs should take folic acid supplements continuously.