An Association of Intrapartum Synthetic Oxytocin Dosing and the Odds of Developing Autism

A case-control study was performed to determine whether an association exists between exposure to synthetic oxytocin and a subsequent autism spectrum disorder diagnosis; 171 children under age 18 meeting "Diagnostic and Statistical Manual of Mental Disorders" (5th ed.) autism spectrum disorder criteria were compared to 171 children without autism spectrum disorder diagnosis matched by gender, birth year, gestational age, and maternal age at birth. A conditional logistic regression model was used to examine the association of clinical variables and autism spectrum disorder. Significantly elevated odds ratios for autism spectrum disorder were associated with first-time Cesarean section (odds ratio=2.56), but not a repeat Cesarean section. Odds ratios were also significantly elevated for subjects whose mother's body mass index was 35 or higher at birth (odds ratio=2.34) and subjects in which the reason for delivery was categorized as "fetal indication" (odds ratio=2.00). When controlling for these and other variables, the odds of developing autism spectrum disorder were significantly elevated in males with long duration of exposure (odds ratio=3.48) and high cumulative dose of synthetic oxytocin (odds ratio=2.79). No significant associations of synthetic oxytocin dosing and autism spectrum disorder were noted in female subjects. The association of elevated autism spectrum disorder odds found with high duration and high cumulative dose synthetic oxytocin in male subjects suggests the need for further investigation to fully elucidate any cause and effect relationship.