OBJECTIVETo quantitatively and comprehensively investigate the association between maternal folate supplementation during pregnancy and the risk of autism spectrum disorder (ASD) in the offspring.

METHODSPubMed, Embase, Scopus, Cochrane Library, EBSCO, CNKI, Wanfang Data, VIP Database, and Chinese Biomedical Database were searched to collect the articles on maternal folate supplementation during pregnancy and the risk of ASD in children. Odds ratio (OR) and 95% confidence interval (CI) were used to determine the effect size. Stata 12.0 software was used for the Meta analysis. Publication bias evaluation and sensitivity analysis were also performed.

RESULTSA total of 10 articles were included according to the inclusion and exclusion criteria, including 15 studies which involved 4 459 cases and 1 225 835 controls. The Meta analysis showed that maternal folate supplementation during pregnancy significantly reduced the risk of ASD in the offspring in the total population (OR=0.798, 95%CI: 0.669-0.952, P=0.012). The subgroup analysis revealed that maternal folate supplementation during pregnancy was associated with a reduced risk of ASD in the offspring in both the Asian population (OR=0.664, 95%CI: 0.428-1.032, P=0.069) and the Western population (OR=0.817, 95%CI: 0.671-0.996, P=0.045).

CONCLUSIONSMaternal folate supplementation during pregnancy may reduce the risk of ASD in the offspring, especially in the Western population.