Autism spectrum disorders (ASD) are complex psychiatric disorders, with both genetic and environmental factors implicated in their etiology. Recent studies suggest the prenatal and early postnatal genesis of ASD, therefore, understanding the effect of environmental risk factors could be important for prevention and treatment of ASD.

The aim of this study was to determine the association of prenatal factors and perinatal complications with ASD.

Our study included 102 subjects with ASD (80% boys) aged 9.35 ± 5.85, and 107 age and sex matched healthy controls (77% boys). For the diagnosis of ASD, we used the ICD-10 criteria and Autism Diagnostic Interview-Revised (ADI-R). A questionnaire regarding prenatal and perinatal factors/complications was administered to all subjects.

Logistic regression model of having autism vs. being a control subject included gender, age, maternal and paternal age at birth, pregnancy order, smoking in pregnancy, number of medication during pregnancy (mostly tocolytics, antihypertensives, antiarrhythmics), and early postnatal complications (mostly prematurity, low birth weight, hyperbilirubinaemia). The model was significant, explaining about the third of variance, with number of medication during pregnancy and having an early postnatal complication as significant predictors.

Our study has shown a significant association of specific prenatal and perinatal factors and ASD, even after controlling for other potential confounding variables. Identifying specific risk factors is important for prevention of ASD. It is also the first step in defining basis of the gene–environment interaction mechanism, which might enable development of an individualised therapeutic approach for this group of disorders.

The authors have not supplied their declaration of competing interest.