Association between autism spectrum disorder and peripartum events: a case-control study

To assess the association between peripartum events and autism spectrum disorder (ASD) development in children and adolescents.

The current research is a case-control study in northern Minas Gerais state, Brazil. The inclusion criteria in the case group included individuals whose medical records reported an autistic disorder diagnosis, individuals had this diagnosis further confirmed by Northern Minas Autistic Support Association and specialized clinics, and their mothers had to answer positively to the question: "Was your child diagnosed with autism spectrum disorder?" in the data collection instrument. Thus, the case group included 253 mothers of children/adolescents of 2-15 years old diagnosed with autism. The inclusion criteria in the control group included 852 individuals belonging to the same age group and enrolled in the same schools as the case group. A semi-structured questionnaire was applied for mothers of children/adolescents, and the multiple logistic regression model was adopted for data analysis. Gross and adjusted Odds Ratios (ORa) were used to estimate the magnitude of the associations.

Autistic disorder was associated with the presence of meconium in amniotic fluid (AF) (ORa 1.67; 95% confidence interval [95%CI] 1.06-2.65) and cesarean delivery type (ORa 1.65; 95%CI 1.17-2.32). Emergency cesarean section increased autistic disorder development likelihood (ORa 2.38; 95%CI 1.61-3.51). Children and adolescents with ASD were more likely to have been exposed to two or more unfavorable peripartum events and obstetric complications than control groups (ORa 1.59; 95%CI 1.01-2.51).

Meconium stained amniotic fluid, delivery by cesarean, and two or more unfavorable peripartum events are variables that should be considered in studies about ASD etiology.