Prenatal folic acid supplementation may lower autism risk for children

A new study from Norway indicates that maternal use of folic acid supplements from four weeks before to eight weeks after the start of pregnancy may be associated with a lower risk of autistic disorder in children.

The observational cohort study analyzed the incidence of autism spectrum disorders (ASDs) (such as autistic disorder, Asperger’s syndrome, and pervasive developmental disorder-not otherwise specified [PDD-NOS]) among 85,176 children whose mothers used folic acid supplements from four weeks before to eight weeks after the start of pregnancy or mothers who did not supplement (1). Over the course of the study, 270 chil-dren (0.32%) were diagnosed with ASDs. The study results showed that folic acid use was associated with a decreased risk of autistic disorder. Specifically, autistic disorder was present in 0.21% of children whose mothers did not take folic acid compared with only 0.10% of children whose mothers took folic acid, which equated to a risk reduction of 39%. No association was found with Asperger’s syndrome or PDD-NOS.

The researchers commented that the new finding indicates that folic acid may – in addition to preventing neural tube defects – also offer benefits by reducing the odds of autism in children. The observation 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 and further investigating genetic factors and other biological mecha-nisms that may explain the association.

1. Berry R. J. et al. Periconceptional folic acid and risk of autism spectrum disorders. JAMA. 2013;
   309(6):611–613.