Adverse labor events and childhood autism – is there a link?

Objective: While the global interest and prevalence of autism spectrum disorder (ASD) are on the rise, the underlying mechanism and potential perinatal risk factors for its development are yet to be fully elucidated. In this study, we have sought to examine the potential association between unfavorable perinatal outcomes and ASD during childhood. Study design: A population-based cohort analysis was conducted that included deliveries at a tertiary referral hospital. The incidence of offspring diagnosed with ASD (both community and hospital-based diagnoses) was compared based on exposure (or lack thereof) to the composite variable “adverse perinatal outcomes” (comprising of 5-min Apgar scores <7, umbilical cord blood pH < 7.0, and non-reassuring fetal heart rate leading to medical intervention). A Kaplan-Meier survival curve was used to assess cumulative ASD incidence. A Cox proportional hazards model was used to control for confounders. Results: Out of the 165,989 births included in the study, 11,070 (6.7 %) had adverse perinatal outcomes. These births were more commonly complicated by intra-uterine growth restriction (4.1 % vs. 1.8 %), preterm delivery (9.6 % vs. 6.6 %), and cesarean delivery (45.3 % vs. 13.4 %; p < 0.001 for all). 862 offspring of the cohort were diagnosed during childhood with ASD. Overall, the cumulative incidence of ASD diagnoses was equivalent comparing adverse perinatal outcomes exposure status (Kaplan-Meier logrank p = 0.690. A Cox proportional hazards model, controlling for ethnicity, gestational age, maternal age, cesarean delivery, and gender, found no association between adverse perinatal outcomes and the risk of ASD (adjusted HR = 0.96, 95 % CI 0.75–1.22, p = 0.72). Conclusion: Adverse labor events, although concerning in terms of immediate neonatal health, do not appear to contribute to a higher risk of ASD in children as they grow older.