Autism Spectrum Disorder and Associated Risk Factors: A Matched Case-Control Study

Despite substantial advances in the etiology of autism spectrum disorder (ASD),the environmental risk factors have not yet been well understood. The present study investigated theassociation between ASD, and maternal and perinatal risk factors. This matched, case-control study was conducted in Hamadan, the west of Iran, fromNovember 2015 to May 2016. We enrolled 41 children with ASD aged 3-17 years. We selected fourcontrols per one case from the same hospital where patients were born. Controls were separatelymatched with cases for sex, age, and birth year. We compared 41 ASD cases with 164 controls. After adjusting the odds ratio (95% CI),ASD was significantly associated with third-degree relatives consanguinity [3.29 (1.39, 7.75)], shortbirth length [4.99 (1.15, 21.60)], short head circumference [7.87 (1.48, 41.76), respiratory distresssyndrome at birth 3.97 (1.91, 8.22)], respiratory assistance at birth [2.92 (1.39, 6.10)], birth hypoxia[2.85 (1.35, 5.99)], and low 1-minute Apgar score [3.65 (1.04, 12.75)]. Our findings suggest that ASD may be associated with multiple maternal and perinatalrisk factors. Evidence based on large prospective multicenter cohort studies is required to indicate theimpacts of maternal and perinatal exposures.