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

Maryam Mohammadian-Khoshnoud,Nasrin Shirmohammadi-Khorram,Tahereh Omidi,Jalal Poorolajal

doi:10.15171/ijer.2019.03

Maryam Mohammadian-Khoshnoud, Nasrin Shirmohammadi-Khorram + Show 2 more

Open Access

https://doi.org/10.15171/ijer.2019.03

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Abstract

Background and aims: 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 the association between ASD, and maternal and perinatal risk factors. Methods: This matched, case-control study was conducted in Hamadan, the west of Iran, from November 2015 to May 2016. We enrolled 41 children with ASD aged 3-17 years. We selected four controls per one case from the same hospital where patients were born. Controls were separately matched with cases for sex, age, and birth year. Results: 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)], short birth length [4.99 (1.15, 21.60)], short head circumference [7.87 (1.48, 41.76), respiratory distress syndrome 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)]. Conclusions: Our findings suggest that ASD may be associated with multiple maternal and perinatal risk factors. Evidence based on large prospective multicenter cohort studies is required to indicate the impacts of maternal and perinatal exposures.

Highlights

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication, restricted and repetitive behaviors, and language impairment
The general consensus is that genetic factors play an important role in the etiology of autism spectrum disorder (ASD) and exposure to environmental factors such as toxic substances, teratogens, and perinatal events may contribute to variable expression of the disease.[7,8]
Evidence based on epidemiological studies has suggested that maternal, perinatal, and neonatal factors such as hypoxia, low Apgar score, abnormal presentation, low birth weight, meconium aspiration, advanced maternal age, diabetes, obesity, and hypertension may increase the risk of developing ASD.[10,11,12,13,14,15,16]

Summary

Introduction

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication, restricted and repetitive behaviors, and language impairment. According to the evidence from different parts of the world, the prevalence of ASD varies from 2 to 20 per 1000, or approximately 1/50 to 1/500 in children.[2,4,5,6]. Despite substantial advances in the etiology of ASD and maternal, perinatal, and neonatal exposures which have been the focus of epidemiologic studies, the environmental risk factors for this disorder have not yet been properly investigated, in developing countries. Until reliable information on the modifiable risk factors for ASD is collected, it is difficult to design and conduct preventive measures. The present study sought to assess the association between ASD and several potential maternal and perinatal risk factors for the disorder

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Conclusion