Prenatal Use of Folic Acid Reduced Autism Likelihood by 40%

Prenatal use of folic acid reduced the likelihood of autism by 40%.

Women who used prenatal folic acid supplements from 4 weeks before pregnancy to 8 weeks after the start of pregnancy had a 40% reduced risk of having a child with an autistic disorder, according to the results of a population-based Norwegian study that examined more than 85,000 children. Study results were published in the Journal of the American Medical Association.

Autistic disorder was found in 0.21% of the children born to mothers who did not take folic acid, compared with 0.10% of children born to mother who did, resulting in an adjusted odds ratio for an autistic disorder of 0.61 (95% CI, 0.41-0.90).

Children in the study were born between 2002 and 2008. The study ended in March 2012. During that time, an autism spectrum disorder was diagnosed in 270 children (0.32% of the population). 

The researchers pointed out that “this finding does not establish a causal relation between folic acid use and autistic disorder but provides a rationale for replicating the analyses in other study samples.”

Read the full results of the study here.