Not breastfeeding and risk of autism spectrum disorders among children: a meta-analysis

BACKGROUND: To our knowledge, this is the first meta-analysis of the association of not breastfeeding and the risk of autism spectrum disorder (ASD) based on observational studies. PURPOSE: This meta-analysis aimed to evaluate of the association of not breastfeeding and the risk of ASD. METHODS: Three databases (PubMed, Web of Science, and Scopus) were systematically searched until December 2021. Heterogeneity was determined using the chi-square test and its quantity was measured using the I(2) statistic. The Begg line regression test was used to assess publication bias. A random-effects model was used to analyze the data. Seven studies were included in this meta-analysis. RESULTS: The total study population included 3,270 individuals. According to the random-effects model, the estimated odds ratio of the risk of ASD associated with not breastfeeding was 1.81 (95% confidence interval, 1.35–2.27; I(2)=0%). CONCLUSION: The results of the included studies were homogeneous. Our findings showed that not breastfeeding is a risk factor for ASD. These results suggest the importance of breastfeeding in decreasing the risk of ASD in children.