Maternal obesity and diabetes during pregnancy and early autism screening score at well-child visits in standard clinical practice

Early intervention can reduce disability in children diagnosed with autism spectrum disorder. Screening for autism spectrum disorder in young children identifies those at increased likelihood of diagnosis who may need further support. This study assessed in utero exposure to maternal obesity and diabetes and offspring performance on the Quantitative Checklist for Autism in Toddlers, an autism spectrum disorder screening questionnaire administered between 18 and 24 months at well-child visits. This retrospective cohort study included 65,433 singletons born in a single healthcare system. Demographic data, maternal obesity, Type 1/Type 2 and gestational diabetes mellitus information, and Quantitative Checklist for Autism in Toddlers score in children 12–30 months old were extracted from electronic medical records. Negative binomial models were used to estimate incidence rate ratios of associations between maternal obesity and diabetes exposure and continuous offspring Quantitative Checklist for Autism in Toddlers scores. Maternal obesity, Type 1/Type 2 diabetes (incidence rate ratio: 1.13, 1.06–1.21) and gestational diabetes mellitus ⩽ 26 weeks (incidence rate ratio: 1.10, 1.05–1.17) were associated with one-unit increases in Quantitative Checklist for Autism in Toddlers scores. Relationships with obesity and gestational diabetes mellitus ⩽ 26 weeks remained after mutual adjustment and excluding children with autism spectrum disorder diagnoses. No associations were reported for gestational diabetes mellitus > 26 weeks. Maternal obesity and diabetes were associated with higher Quantitative Checklist for Autism in Toddlers scores in children 12–30 months old, suggesting these exposures in pregnancy may be associated with a range of early childhood behavior. Lay Abstract Early intervention and treatment can help reduce disability in children diagnosed with autism spectrum disorder. Screening for autism spectrum disorder in young children identifies those at increased likelihood of diagnosis who may need further support. Previous research has reported that exposure to maternal obesity and diabetes during pregnancy is associated with higher likelihood of autism spectrum disorder diagnosis in children. However, little is known about whether these maternal conditions are associated with how very young children score on autism spectrum disorder screening tools. This study examined associations between exposure to maternal obesity and diabetes during pregnancy and off