Autism in India: a case-control study to understand the association between socio-economic and environmental risk factors.

Autism spectrum disorder is a neurodevelopmental disorder and the cause of autism is still unclear. The aim of this study was to investigate the association of socioeconomic, environmental, pregnancy and newborn-related risk factors among children with autism spectrum disorders. This was a population-based case-control study. The study included 55 children with autism spectrum disorder and 55 age and sex matched typically developing normal children (TD) between 3 and 12 years. Several socio-economic factors, environmental factors, pregnancy related, natal, post-natal factors and the first noticed signs by the parents were analyzed. Chi-square test was used to compare nominal variables. For multivariate analysis, forward stepwise logistic regression model was employed to examine the association between autism and the chances that the child develops ASD to assess the odds ratios. Male predominance was observed in the study. Logistic regression model showed statistical significance of the following factors: paternal age greater than 40 years, family history of autism, nutrition during pregnancy, mode of labor, fetal hypoxia, NICU stay and history of breast feeding. In this epidemiological study of autism in Coimbatore city, we found correlation between several environmental factors during fetal development and can be transmitted to succeeding generations, causing atypical behavior phenotypes. The exact exposure magnitude, exposure time in relation to vital developmental periods need to be studied to understand the influence of socioeconomic and environmental factors, which can be improved to prevent ASD-related challenges.