Taking lower folic acid during pregnancy can increase the risk of autism in the offspring reduce, observational study showed.

Compared with women who had no dietary supplements, taking folic acid supplement from 4 weeks before and 8 weeks after conception less likely that children, later with an autistic disorder (0.1% vs. 0.21%, OR 0.61 95% CI 0.41 to 0.90 diagnosed), in accordance with PAL Suren, MD, MPH, of the Norwegian Institute of Public Health in Oslo, and colleagues.

No similar associations in Asperger’s syndrome or pervasive developmental disorder otherwise specified (PDD-NOS) were observed, the researchers reported in the February 13 issue of the Journal of the American Medical Association.

The study “does not prove a causal relationship between folic acid use and autism, but provides justification for replicating the analysis in other study samples and further investigation of the genetic and other biological mechanisms that may explain the inverse relationship”, Suren and his colleagues wrote.

“The finding that could periconceptional supplement use, the risk of autism is to reduce encouraging, but it is important to confirm this finding in other population cohorts”, Robert Berry, MD, MPHTM, a division of the CDC Birth Defects and Developmental Disabilities, Atlanta, and colleagues wrote in an accompanying editorial.

The fact that folic acid was not associated with an increased risk of autism spectrum disorders is reassuring, they said, and “it should ensure that folic acid may continue to serve as a tool for the prevention of neural tube birth defects.”

Effects of maternal folic acid on the results other than neural tube birth defects is still uncertain, although previous studies have found associations with a lower risk of severe language delays and autism spectrum disorders (ASD).