Maternal Cesarean Section and Offspring ASD or ADHD Risk: A Nurses' Health Study II Analysis

Epidemiological evidence on whether cesarean delivery influences offspring neurodevelopment remains inconsistent. We evaluated the associations between maternal cesarean delivery and childhood autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in the Nurses' Health Study II cohort. We included 29 352 mothers and their children in the ASD analysis and 27 704 in the ADHD analysis. We used generalized estimating equations to estimate the odds ratio (OR) and 95% confidence interval (CI) for the child outcomes according to the mode of delivery. We evaluated confounding effects from maternal demographic and reproductive factors, chronic health and pregnancy complications, previous cesarean delivery, and lifestyle factors. We examined current cesarean delivery in combination with the history of mode of delivery, and we performed a sibling comparison analysis to evaluate the influence of uncontrolled confounding. Despite some suggestions in crude analyses, there was no association between birth by cesarean delivery and child ASD (OR = 1.02, 95%CI 0.81-1.29) nor ADHD (OR = 1.06, 95% CI 0.95-1.18) in fully adjusted models. Analyses considering maternal history of cesarean deliveries or comparing the siblings did not change the main findings. Our study does not support the hypothesis that birth by cesarean delivery increases the risk of ASD or ADHD.