Hypertensive disorders of pregnancy increase the incidence of febrile seizures in offspring

Background: Intrauterine exposure to hypertensive disorders of pregnancy (HDP) may increase the risk of neuropsychiatric disorders. This investigation examined for associations between maternal HDP and febrile seizures (FS) in offspring by the age of three years. Methods: The present cohort study analyzed data from the Japan Environment and Children’s Study, a large national birth cohort. We included mother-child pairs recruited between January 2011 and March 2014. Information regarding maternal HDP, the presence of FS in offspring up to 3 years of age, and potential confounding factors were assessed using written questionnaires administered to mothers. Results: A total of 77,699 mother-child dyads were analyzed. The prevalence of FS was 8.4% in children without HDP exposure, 10.6% in those exposed to mild HDP, and 10.4% in those with severe HDP exposure. Among children with full-term birth, logistic regression analysis indicated that exposure to mild or severe HDP was significantly associated with a higher incidence of FS (adjusted odds ratio [95% confidence interval]: 1.27 [1.05–1.53] and 1.27 [0.90–1.78], respectively, P for trend = 0.008), compared with children without HDP exposure. Conclusion: In children with full-term birth, intrauterine exposure to HDP was significantly associated with FS by the age of three years. Impact: This study revealed a significant association between intrauterine exposure to hypertensive disorders of pregnancy (HDP) and the subsequent development of febrile seizures (FS) in offspring by three years. This increased incidence of FS by HDP was independent of preterm birth status. This is the first large nationwide birth cohort study showing the impact of intrauterine exposure to HDP on FS in early childhood.