Association of the Maternal Folic Acid Supplementation with the Autism Spectrum Disorder: A Systematic Review.

Objective:  To analyze the scientific production regarding maternal folic acid (FA) supplementation and its relationship with autistic spectrum disorder (ASD).

Data Sources:  We performed unrestricted electronic searches in the BIREME virtual bank, Virtual Health Library (VHL) and Medical Literature Analysis and Retrieval System Online (MEDLINE/PubMed) databases.

Selection Of Studies:  For sample selection, articles that met the proposed objectives were included, published in English, Spanish and Portuguese, the use of Health Sciences Descriptors (DeCS): OR AND AND , AND, with the use of the Medical Subject Headings (MeSH): autistic OR AND AND .

Data Collection:  Data extraction was performed by the reviewers with a preestablished data collection formulary.

Data Synthesis:  The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) was used based on a checklist with 27 items and a 4-step flowchart.

Results:  A total of 384 articles was found by the search strategies, of which 17 were eligible following the pre-established criteria. The main findings of the present review point to maternal FA supplementation in the pre-conception period and beginning of pregnancy as a protective effect in relation to ASD, which should be indicated in this period as prevention to the problem.

Conclusion:  According to the research analyzed, more studies are necessary to know its effects on pregnancy, since the consumption of excessive FA may not be innocuous.