Association of seizure control during pregnancy with adverse offspring outcomes in women with epilepsy

Background Information on fetal risks with maternal seizures during pregnancy is scarce. This study investigates seizure control during pregnancy and fetal risks associated with maternal seizures in different stages of pregnancy among pregnant women with epilepsy (PWWE). Methods The nested case–control study enrolled PWWE between 2009 and 2023 in China. Information was obtained on maternal seizures, antiseizure medication (ASM), folic acid supplementation and pregnancy outcomes. The primary outcome was composite including major congenital malformations (MCMs), neurodevelopmental delay, low birth weight (LBW) and fetal death. Univariate and multivariate logistic regression analyses were conducted to adjust for ASM effects and other confounders. Results Among 1110 pregnancies from 934 PWWE included, 56.6% experienced seizures. Seizure deterioration during pregnancy compared with prepregnancy was observed in 25.9% of pregnancies, while 20.9% experienced worsening seizures from the first to second or third trimesters. Seizures (adjusted OR (aOR) 1.472, 95% CI 1.024 to 2.137), particularly status epilepticus (aOR 2.906, 95% CI 1.364 to 5.93), generalised tonic-clonic seizures (aOR 1.581, 95% CI 1.066 to 2.354) and seizure deterioration (aOR 1.829, 95% CI 1.233 to 2.69) were associated with composite adverse outcomes. Specifically, seizures occurring (aOR 2.324, 95% CI 1.320 to 4.084) or deteriorating (aOR 2.396, 95% CI 1.471 to 3.866) during second and third trimesters were associated with the risk of LBW. No significant association was found between seizures and MCMs. Conclusions While nearly half of PWWE remain seizure-free during pregnancy, those who do experience seizures face increased risks of adverse offspring outcomes. For PWWE, every effort should be made to optimise seizure control in order to minimise risks to both mother and child. Trial registration number: ChiCTR2100046318