Association of severe maternal morbidity with epilepsy diagnosis in children: a population-based birth cohort study

Severe maternal morbidity (SMM) is associated with adverse perinatal outcomes. However, its association with longer-term offspring outcomes, including neurodevelopment disorders, is poorly understood. This study aims to examine the association between SMM and the risk of epilepsy in offspring.

A retrospective birth cohort study of all singleton hospital births between 2002 and 2018 in Ontario, Canada was followed up until March 2020. SMM (20 weeks' gestation to 42 days postpartum) and epilepsy diagnosed before 18 years of age in offspring were identified by using administrative health records. The risk of epilepsy associated with SMM was estimated by using Cox proportional hazard models and the robustness of the results was examined by using quantitative bias analyses (outcome and exposure misclassification and residual or unmeasured confounding).

Of 2 060 668 children with a median follow-up time of 10 years, 40 830 (2%) were exposed to severe maternal morbidity and 16 992 (0.8%) were diagnosed with epilepsy (1.2% among those exposed to SMM and 0.8% among those unexposed). After adjustment for maternal, birth, and socioeconomic characteristics, children exposed to SMM had a 45% increased risk of epilepsy diagnosis compared with those unexposed [hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.33-1.59]. This increase was similar across the subtypes of SMM. Estimates accounting for potential misclassification biases and residual or unmeasured confounding (by obesity or maternal education) showed increased risks (HR 1.91, 95% CI 1.50-2.42).

An increased risk of epilepsy was found in children exposed to SMM, suggesting a perinatal etiology and underlining the importance of ensuring a healthy pregnancy.