Abstract
The aetiology of autism spectrum disorder (ASD) is heterogeneous and is attributed to the concurrent interaction of a number of genetic and environmental factors. The steady increase in ASD rates in recent years makes the detection and study of environmental risk factors increasingly important. This systematic review identifies potential environmental factors associated with ASD focusing specifically on recent studies conducted in selected Southern European countries. Nine relevant studies were selected for this systematic review. Results indicate that ASD in Southern Europe is associated with a variety of prenatal, perinatal and postnatal environmental factors, including stressful early life events, maternal infection during pregnancy, delivery mode and perinatal complications or breastfeeding problems in the offspring. Specially designed, large population-based birth cohort studies are needed in Southern Europe, to allow precise assessment of potential environmental confounders and elucidate their association with ASD.