Prenatal Risk Factors for Autism Spectrum Disorder in Children who were Born in the Soroka University Medical Center Between the Years 2009-2013 -

Hernan Kosovsky ⁷ Gal Meiri ⁴ Ilan Dinstein ^2,3 Hagit Flusser ⁵ Enalya Michaelovsky ⁵ Asher Bashiri ⁶ Idan Menashe ¹

¹Department of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel
²Psychology Department, Ben Gurion University, Beer Sheva, Israel
³Cognitive and Brain Sciences Department, Ben Gurion University, Beer Sheva, Israel
⁴Pre-School Psychiatry Unit, Soroka University Medical Center, Beer Sheva, Israel
⁵Zusman Child Development Center, Soroka University Medical Center, Beer Sheva, Israel
⁶Department of Obstetrics and Gynecology, Soroka University Medical Center, Beer Sheva, Israel
⁷Goldman Medical School, Faculty of Health Sciences, Ben-Gurion University of the Negev, Israel

Background: The steady increase in the incidence of autism spectrum disorder (ASD) in recent decades has triggered increasing efforts in understanding involvement of environmental risk factors. Exposure to various factors during pregnancy and their association to the risk of ASD have been the subject to many epidemiological studies in the last 20 years.

Objectives: To study the association between prenatal risk factors and ASD.

Design: A matched case-control study including 347 children with ASD and 1,655 controls that were matched to cases based on their age, sex, and ethnic origin. Demographic and clinical data were collected from two databases at the Soroka Medical Center: (1) regional database of the Negev Autism Center; (2) database of the Obstetrics and Gynecological Department. The parameters that were found to be significantly associated with ASD in the univariate tests were used in the multivariate analysis using a conditional logistic regression model.

Results: Our univariate analysis indicated a significant association between ASD and a number of maternal risk factor. Specifically, variables that were more prevalent in the ASD group compared to controls were: psychiatric conditions (4.3% and 1.8% respectively, p<.01), pain disorders (10.4% and 4.3%, p<.001), overweight and obesity (18.7% and 8.8%, p<.001), s/p bariatric surgery (3.2% and 0.9%, p<.001), Allergic purpura (9.2% and 6.2%, p<.05) and Tobacco use disorder (14.4% and 9.7%, p<.01). In a multivariate conditional logistic regression the following factors remained significantly associated with ASD: Parity (OR 0.899 for every birth p=.001); Pregnancy from artificial insemination (OR of 2.864 p<.05); Mother`s that had a diagnosis of a psychiatric condition (OR 1.956 p<.05); Mothers with overweight or obesity (OR 2.02 p<.001).

Conclusions: The multiple prenatal risk factors that were found in this study support the multi-factorial premise of this disorder, and highlight the role of pregnancy factors in its etiology.

Keywords: Autism spectrum disorder, obstetric, environmental and prenatal risk factors, child psychiatry