For the study, the researchers followed 85,176 Norway-born children born in Norway, 114, or 0.13%, of whom had autistic disorder. The team discovered that 0.2% of the children whose mothers did not take the B vitamin, folic acid, had autism, compared to 0.1% of the children of mothers who took the vitamin in pill form. However, the researchers did not find a relationship between folic acid and Asperger’s syndrome, a related condition, or pervasive developmental disorder, but this may be because those conditions are rare and there were not enough cases to show a difference.
But what do the findings mean to you? If you take folic acid supplements before and early in pregnancy you are 39% less likely to have autistic children, or, put another way, in every 10 children who would have become autistic without the folic acid supplements, 6 would be autistic with them. However, the researchers found that the beneficial effect of autism prevention was only apparent if mothers took the folic acid supplements during the six weeks before and the six weeks after conception.
Wellness experts already recommend that pregnant women take folic acid supplements, because it can protect your baby’s wellbeing against neural tube defects, which are often severe malformations of the brain. In terms of this study, however, Halladay warns that taking folic acid ‘doesn’t prevent autism.’ She explained that other factors, including infections early in pregnancy, premature birth, and pesticide and chemical exposure, can increase your child’s chance of becoming autistic, and ‘clearly some women who take folic acid will go on to have an autistic child. But [taking folic acid] is something that women can do and can feel empowered to do.’