Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 47 9 2018 08 29 1387 1395 Seyyed Mohammad MOUSAVI Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran AND Genetic and Identification Lab, Legal Medicine Center, Isfahan, Iran Elahe KAMALI Division of Genetics, Dept. of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran Fatemeh FATAHI Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran Hadi BABAIE Dept. of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran AND Genetic and Identification Lab, Legal Medicine Center, Rasht, Iran Mansoor SALEHI Dept. of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran AND Medical Genetics Center of Genome, Genome Building, Isfahan, Iran 2018 08 29 2018 08 29 Background: Due to the importance of prenatal maternal stress as environmental factor on autism, the influence of prenatal maternal psychological agitations was assessed in relation with the risk of autism. Methods: In this case-control study, some mothers of autistic children in Isfahan, central Iran, in 2014, were retrospectively compared with control mothers in terms of quantity, quality, andschedule of exposure to 45 stressful events in a 15-month period. In addition, dividing the stressors into two groups of genome-dependent/independent events, their prevalence was separately scrutinized and compared among patient and control families. Results: Although the child’s risk of autism increases significantly with the increase of maternal stress during months 4-7 of pregnancy, the increased stress during months 2-3 of pregnancy can lead to a significant increase in the severity of autism affliction as well as a slight but significant increase in the possibility of LFA in afflicted children (P<0.05). The overall prevalence of genome-dependent stressful events among two patient and control groups was significantly higher than that of genome-independent events (P=0.000), but genome-dependent events led to more stress inpatient families. Conclusion: Although the present study consistent with recent findings in the fields of epigenetics and gene-environment interactions can confirm the role of severe and scheduled prenatal stresses in causing autism, it does not deny the necessity of a perspective and wider study in Isfahan and Iran.     https://ijph.tums.ac.ir/index.php/ijph/article/view/14595 https://ijph.tums.ac.ir/index.php/ijph/article/download/14595/6121