Autism spectrum disorder (ASD)-a case-control study to investigate the prenatal, perinatal and neonatal factors in Indian Population

Abstract

Globally, Autism spectrum disorder (ASD) has been rapidly increasing in the past decades, and still the aetiological factors that contribute to ASD remains unclear. Since a wide plethora of factors can be involved in the development of ASD, we aimed to investigate various paternal, prenatal, perinatal, neonatal and environmental risk factors using broad and reliable classification methods. The targeted population were children (between 3 -18 years) residing in Tamil Nadu, India and were identified as children with ASD (n = 346) on the basis of DSM-V and CARS. Each child was matched by gender and age (±2) to 1038 controls (735 males, 303 females) in a case-control design in the ratio 1:3. Questionnaires and other medical records of participants and controls were surveyed according to the study criteria. The prenatal risk factors that were significant for children with ASD were advanced parental age, parental smoking and passive smoking, stress and environmental exposures during pregnancy. The significant neonatal factors were hypoxia and birth-weight. Hypoxia was a significant neonatal factor that was different among ASD children and controls and birth weight emerged as a prominent factor associated with autism severity. Additional investigations focused on both genetic and environmental factors that link these ASD risk factors individually or collectively are needed. Hence, an accurate understanding of etiology can help in comprehending the intricacies of this multifaceted condition and may pave way for early diagnosis, prevention and treatment of ASD.