The association between maternal prenatal folic acid and multivitamin supplementation and autism spectrum disorders in offspring: An umbrella review.

This large review looked at whether taking folic acid or multivitamins during pregnancy might reduce the chance of having a child with autism. Researchers combined data from many studies involving over 3 million mothers and their children. They found that mothers who took these supplements during pregnancy had about a 30% lower chance of having a child with autism. Both folic acid alone and multivitamins showed protective effects.

This umbrella review synthesized evidence from 8 systematic reviews and meta-analyses examining the association between maternal prenatal folic acid and multivitamin supplementation and autism spectrum disorder (ASD) risk in children. The analysis included 101 primary studies covering over 3 million mother-offspring pairs. Results showed that prenatal folic acid and/or multivitamin supplementation was associated with a 30% reduced risk of ASD in offspring (RR = 0.70, 95% CI: 0.62-0.78). Subgroup analysis revealed that multivitamin supplementation reduced ASD risk by 34% (RR = 0.66) while folic acid alone showed a 30% reduction (RR = 0.70).

Both associations were graded as 'highly suggestive' evidence, suggesting important public health implications for prenatal supplementation recommendations.

These findings support prenatal folic acid and multivitamin supplementation as a potential preventive strategy for ASD. The evidence suggests healthcare providers should emphasize the importance of prenatal supplementation not only for neural tube defect prevention but also for potential ASD risk reduction, with implications for public health policy and prenatal care guidelines.

The abstract does not specify limitations of the included studies, potential confounding factors, or methodological concerns. Information about heterogeneity between studies, dosage effects, timing of supplementation, or quality of primary studies is not provided in the available abstract.

Previous reviews have examined the association between maternal prenatal use of folic acid and multivitamin supplements and autism spectrum disorder (ASD) in children, but findings remain inconclusive. This umbrella review aims to synthesise the existing evidence on the association between prenatal folic acid and multivitamin supplementation and the risk of ASD in offspring. This umbrella review followed the PRISMA guidelines to synthesise and report evidence from existing systematic reviews and meta-analyses (SRMs). Articles were searched in PubMed, Scopus, Web of Science, and Google Scholar.

The quality of included studies was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR). A weighted inverse variance random-effects model was applied to estimate pooled effects. The association was quantified using relative risks (RRs) with 95% confidence intervals (CIs). Subgroup analysis and sensitivity analysis were also conducted.

Heterogeneity and publication bias were assessed. Eight SRMs comprising 101 primary studies and over three million mother-offspring pairs were included. Prenatal folic acid and/or multivitamin supplementation was associated with a 30% reduced risk of ASD in offspring (RR = 0.70, 95% CI: 0.62, 0.78; GRADE: highly suggestive). Subgroup analysis by supplement type showed that maternal prenatal multivitamin supplementation reduced the risk of ASD by 34% (RR = 0.66, 95% CI: 0.55-0.80; GRADE: highly suggestive), while folic acid supplementation was associated with a 30% reduction in ASD risk (RR = 0.70, 95% CI: 0.60-0.83; GRADE: highly suggestive).

Maternal prenatal folic acid and multivitamin supplementation are associated with a reduced risk of ASD in offspring. These findings have important public health implications, suggesting that prenatal supplementation could help mitigate the risk of ASD in children.