Folic Acid in Pregnancy May Lower Autism Risk
Over an average of six years of follow-up, 270 children were diagnosed with autism spectrum disorders, 114 with autism, 56 with Asperger syndrome and 100 with an unspecified autism disorder.
Among those mothers who took folic acid supplements, 0.10 percent of their children were diagnosed with autism, compared with 0.21 percent of children whose mothers didn't take folic acid. That's a 39 percent lowered risk for the neurodevelopment disorder, Suren said.
Women who took the supplements were more likely to be better educated and have planned their pregnancy. They were also likely to be thin and not smoke. For most, it was their first child, the researchers added.
Suren's group did not find a connection between folic acid and either Asperger syndrome or unspecified autism disorder. "For Asperger syndrome, the number of children was too low to obtain sufficient statistical power in the analyses," Suren explained.
The protective affect of folic acid seemed to work even if not taken until early pregnancy. No protection from folic acid was seen if taken at mid- pregnancy, the researchers noted.
"The results support the current recommendations of taking folic acid supplements during pregnancy and emphasize the importance of starting early, preferably before conception," Suren said.
Halladay said the study finding confirms the results of another study that showed that folic acid might reduce the risk of autism. "The benefits of prenatal care, including taking vitamins, has been well-documented for things like birth defects and even language delay," she said.
Whether or not folic acid supplementation will make a dent in the growing number of children diagnosed with autism spectrum disorder isn't known. An estimated one in 88 children in the United States has been diagnosed with some form of autism spectrum disorder, according to the federal Centers for Disease Control and Prevention.
In the United States and other countries many foods, such as breads and pasta, are fortified with folic acid to help prevent birth defects. But, it isn't clear yet how much folic acid might guard against autism, so a woman should discuss her options with her doctor, Halladay said.