Cesarean Section as a Predictor for Autism: a Case-Control Study in Valencia (Spain)

Abstract

Growing interest has been shown in recent decades in the role of perinatal factors in relation to autistic spectrum disorders (ASD). Several studies have identified that cesarean sections (CS) could be a risk factor for ASD. The objective was to evaluate the relationship between CS and ASD in childhood as an early indicator for ASD diagnosis. This is a hospital-based nested case-control study in a retrospective cohort of births during 1996–2011. Cases were defined as children diagnosed with ASD at the Neuropediatric Unit of the La Fe Hospital in the last 10 years and controls as children without ASD. After pairing controls with cases for children’s date of birth at a 4:1 ratio, 251 mother-child pairs (53 cases, 198 controls) were studied, for whom information about perinatal risk factors, such as mode of delivery (vaginal vs. CS), and potential confounders was collected. Of the children identified, the control group was made up of 100 boys and 98 girls while the case group included 47 boys and 6 girls. A multivariable conditional logistic regression model was built (matched by children’s date of birth) to assess any potential association in relation with ASD diagnosis, where birth by CS presented a cOR = 3.37 (95% CI 1.57–7.25) of ASD. The adjusted model (for maternal age, child’s sex, gravidity, and gestation weeks) suggested a relation between CS and ASD (aOR = 3.36, 95% CI 1.44–7.85). The results suggest that the probability of ASD after a birth by CS is over three times that observed after unassisted vaginal delivery. Large prospective studies are needed to understand if this relationship is a causal pathway or consequence of ASD. The results suggest that using birth by CS as a predictor for ASD by pediatric health professionals in their patient follow-ups may be an appropriate tool that could improve early ASD detection.