Risk Factors for Autism: A Comprehensive Summary

Abstract

Objective: To review the evidence for the presence of etiological factors that affect the risk of autism and autism spectrum disorders.

Autism is a chronic neurodevelopmental disorder characterized by social and language impairments and stereotyped, repetitive patterns of behavior. Symptoms manifest by the age of 3 years, and affected individuals often require constant care from family members and professionals. Other disorders that are included in the autism spectrum include atypical autism, Asperger disorder, Rett disorder, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified. The etiology of autism is unknown, although the risk factors based on pre-, peri-, neonatal and environmental exposures have been the focus of epidemiologic research for over 40 years. Current evidence suggests that several environmental factors are unrelated to risk of ASD. Birth complications that associated with trauma or ischemia and hypoxia have shown strong links to ASD, whereas other pregnancy-related factors such as maternal obesity, maternal diabetes, and C/S have shown a weak association with risk of ASD (Modabbernia & Velthorst et al, 2017).

In this study, systematic reviews and meta-analyses of risk factors for ASD were reviewed to provide an overview of the evidence of the presence of the risk factors of autism and autism spectrum disorder. Relevant articles were identified by searching the internet and 15 case histories eligible were reviewed for the study. The summary of the study reveals the presence of etiological factors of autism as reported by the articles, were present in the case histories studied.