Prenatal Exposure to Antiseizure Medication and Risk of Adverse Obstetrical Outcomes: A Population-Based Study
Author(s)
Payam Peymani, Pharm.D, PhD1, Anick Berard, MSc, PhD2, Alekhya Lavu, PharmD, PhD1, Christine Leong, Pharm.D1, Jamie Falk, Pharm.D1, Joseph A Delaney, MSc, PhD3, Kaarina Kowalec, MSc, PhD1, Marcus Ng, MD4, Chelsea Ruth, MD5, Laila Aboulatta, PharmD1, Silvia Alessi-Severini, PhD1, Roxana Dragan, MSc6, Sherif Eltonsy, PhD1;
1College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada, 2Faculty of Pharmacy, University of Montreal, Montreal, QC, Canada, 3Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, USA, 4Section of Neurology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada, 5Department of Pediatrics and Child Health, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada, 6Manitoba Centre for Health Policy, Winnipeg, MB, Canada
1College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada, 2Faculty of Pharmacy, University of Montreal, Montreal, QC, Canada, 3Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, USA, 4Section of Neurology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada, 5Department of Pediatrics and Child Health, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada, 6Manitoba Centre for Health Policy, Winnipeg, MB, Canada
Presentation Documents
OBJECTIVES: Antiseizure medications (ASMs) are frequently prescribed during pregnancy, yet their potential impact on obstetrical outcomes remains insufficiently characterized. Understanding the risks associated with ASM use during pregnancy is essential for clinical decision-making. This study aim to evaluate the association between prenatal ASM exposure and obstetrical outcomes, including premature rupture of membranes (PROM), cesarean section, placental abruption, gestational diabetes, and pre-eclampsia.
METHODS: A population-based cohort study was conducted using data from the Manitoba Research Data Repository (1998-2019). Pregnancies were classified by epilepsy diagnosis and ASM exposure. High-Dimensional Propensity Score (HDPS) and multivariable logistic regression models adjusted for maternal characteristics (age, chronic conditions, psychiatric history, socioeconomic status, and other covariates) were used to estimate odds ratios (ORs) for obstetrical outcomes. Stratified analyses examined risks by ASM type, timing, and number of exposures.
RESULTS: Among 297,734 pregnancies, 4,187 (1.4%) were exposed to ASMs, predominantly during the first trimester (1.3%). PROM occurred more frequently in ASM-exposed pregnancies (17.8%) compared to unexposed pregnancies (14.9%; adjusted OR = 1.18, 95% CI: 1.09-1.29). Cesarean section rates were numerically elevated (24.1% vs. 21.2%; adjusted OR = 1.06, 95% CI: 0.99-1.13). Placental abruption was significantly more common among ASM-exposed pregnancies (2.1% vs. 1.1%; adjusted OR = 1.58, 95% CI: 1.25-1.98). Gestational diabetes was also more frequent (10.7% vs. 6.3%; adjusted OR = 1.19, 95% CI: 1.05-1.34). Stratified analyses revealed that gabapentin and valproic acid were associated with higher risks for specific outcomes, while multiple ASM exposures resulted in compounded adverse outcomes, including reduced mean birth weight (3293 g for one ASM vs. 3211 g for two ASMs).
CONCLUSIONS: Prenatal antiseizure medication (ASM) exposure slightly increases risks of certain obstetrical complications. This highlights the need for individualized assessment and monitoring of pregnant women on ASMs. More research is needed on specific ASMs, especially gabapentin and valproic acid, to guide prescribing during pregnancy.
METHODS: A population-based cohort study was conducted using data from the Manitoba Research Data Repository (1998-2019). Pregnancies were classified by epilepsy diagnosis and ASM exposure. High-Dimensional Propensity Score (HDPS) and multivariable logistic regression models adjusted for maternal characteristics (age, chronic conditions, psychiatric history, socioeconomic status, and other covariates) were used to estimate odds ratios (ORs) for obstetrical outcomes. Stratified analyses examined risks by ASM type, timing, and number of exposures.
RESULTS: Among 297,734 pregnancies, 4,187 (1.4%) were exposed to ASMs, predominantly during the first trimester (1.3%). PROM occurred more frequently in ASM-exposed pregnancies (17.8%) compared to unexposed pregnancies (14.9%; adjusted OR = 1.18, 95% CI: 1.09-1.29). Cesarean section rates were numerically elevated (24.1% vs. 21.2%; adjusted OR = 1.06, 95% CI: 0.99-1.13). Placental abruption was significantly more common among ASM-exposed pregnancies (2.1% vs. 1.1%; adjusted OR = 1.58, 95% CI: 1.25-1.98). Gestational diabetes was also more frequent (10.7% vs. 6.3%; adjusted OR = 1.19, 95% CI: 1.05-1.34). Stratified analyses revealed that gabapentin and valproic acid were associated with higher risks for specific outcomes, while multiple ASM exposures resulted in compounded adverse outcomes, including reduced mean birth weight (3293 g for one ASM vs. 3211 g for two ASMs).
CONCLUSIONS: Prenatal antiseizure medication (ASM) exposure slightly increases risks of certain obstetrical complications. This highlights the need for individualized assessment and monitoring of pregnant women on ASMs. More research is needed on specific ASMs, especially gabapentin and valproic acid, to guide prescribing during pregnancy.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
EPH108
Topic
Epidemiology & Public Health
Topic Subcategory
Safety & Pharmacoepidemiology
Disease
SDC: Neurological Disorders, SDC: Reproductive & Sexual Health, STA: Multiple/Other Specialized Treatments