Prenatal Maternal Alcohol Exposure During the First Trimester of Pregnancy in Relation to Early Learning Ability, Behavioral Problems, and Autistic Traits in Preschool Children With or Without Autism Spectrum Disorder.

Prenatal alcohol exposure has been linked to adverse neurodevelopmental outcomes. However, its effects on developmental outcomes in children with autism spectrum disorder (ASD) remain unclear. We examined associations between prenatal alcohol exposure during the first trimester (PAE-FT) and early learning ability, behavioral problems, and severity of autistic traits in preschool-aged children in a large multi-site case-control study, the Study to Explore Early Development. Children were classified as ASD (n = 1237) or population comparison without ASD (POP, n = 1334) after an in-person assessment covering cognitive abilities and detailed autistic traits. Mothers completed questionnaires on their child's behavior and autism-related traits, as well as their alcohol use during pregnancy. Of children in the ASD and POP groups, 18.5% and 20.2%, respectively, were exposed to PAE-FT. Exposure to 3 or more alcoholic drinks per week was associated with increased externalizing behaviors (i.e., attention deficits and aggressive behaviors) in children in both the ASD and POP groups, and with exacerbated social communication and interaction deficits in children with ASD only. First trimester exposure to 1-2 alcoholic drinks per week was associated with early learning delays for children in the ASD group, but not the POP group. As expected, our findings suggest that PAE-FT is associated with adverse behavioral development of children regardless of ASD status. However, PAE-FT may exacerbate autism-specific developmental problems and learning difficulties in children with ASD. Gathering a prenatal alcohol exposure history for children with and without ASD could contribute to a better understanding of developmental trajectories, aiding informed decisions for interventions and support.