The new study in the Journal of the American Medical Association, asked whether or not prenatal folic acid use reduces the risk of autism spectrum disorders (ASDs include autistic disorder, Asperger syndrome, pervasive developmental disorder–not otherwise specified [PDD-NOS]) in children.
In the study, more than 85,000 Norwegian children born between 2002-2008 were followed through March of last year. Scientists focused on the maternal use of folic acid from 4 weeks before to 8 weeks after the start of pregnancy. (Pregnancy is defined as the first day of the last menstrual period before conception.)
Researchers discovered 270 children in the study were diagnosed with ASDs: 114 with autistic disorder, 56 with Asperger syndrome, and 100 with PDD-NOS.
That means in children whose mothers took folic acid, 0.10 percent had autistic disorder, compared with 0.21 percent in those unexposed to folic acid.
According to doctors Robert J. Berry, MD, MPHTM; Krista S. Crider, PhD; Marshalyn Yeargin-Allsopp, MD, "autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders characterized by significant impairments in social interaction and communication and by repetitive, restrictive, and stereotyped patterns of behavior. The most serious of the conditions comprising ASDs is autistic disorder, because it is likely to co-occur with intellectual disability and a range of medical, behavioral, and psychiatric complications. The prevalence of ASDs is estimated to be approximately 1% of children."
Prenatal folic acid supplements have previously been associated with the reduced risk of neural tube defects in children.