The Association between Threatened Abortion and the Risk of Autism Spectrum Disorders among Children: A Meta-Analysis

Abstract

Background: The current study is aimed at updating the observational studies on the relationship between threatened abortion and the risk of ASD.

Methods: The search keywords were covered in three electronic databases PubMed, Web of Science, and Scopus up to April 2022. The modified Newcastle-Ottawa scale (NOS) was applied to detect the quality of epidemiological studies. We used the chi-square test and the I ² statistic to show the heterogeneity among articles. I ² more than 50% was considered high heterogeneity. Egger's and Begg's line regression tests were used for evaluating the publication bias. The random-effects model was applied for the analysis of the findings. The Stata 13.0 software package was applied for analysis and indicated p value less than 0.05 as a significant level.

Results: The pooled analysis reported significant differences between threatened abortion and the risk of ASD in adjusted studies (OR = 1.93; 95% CI: 1.12, 2.73; I ² = 59.5.0%) and in crude studies (OR = 2.17; 95% CI: 1.46, 2.88; I ² = 39.5%). The evidence of publication bias was not found.

Conclusions: The findings suggest that threatened abortion is a risk factor for ASD. As a result, screening tools to detect are necessary in mothers facing a threatened abortion.