(NEW YORK) -- Folic acid has been recommended to pregnant women for years, usually as a way to prevent birth defects such as spina bifida.
But a new study published Tuesday in the Journal of the American Medical Association found it may also prevent autism.
The JAMA study, which used data from the Norwegian Mother and Child Cohort Study, found that mothers who took folic acid four weeks before and eight weeks after pregnancy had a 40 percent reduced risk of giving birth to a child with autism. While the researchers found an association between folic acid deficiency and autism, that does not mean that folic acid taken during pregnancy would result in fewer autism cases.
The Norwegian Mother and Child Cohort Study followed more than 85,000 babies born between 2002 and 2008, and their parents. About 270 babies whose parents participated in the study were born with a developmental disorder on the autism spectrum.
Mothers reported whether they were taking folic acid before and during early pregnancy before they found out whether their children had autism, which eliminated some potential bias, said molecular epidemiologist Rebecca Schmidt, a professor at the University of California, Davis School of Medicine. In 2011, Schmidt was one of the first scientists to publish a study that found that autism arises because of both genetic and external factors, including women’s prenatal vitamin intake before conception.
“Given the replication of findings showing reduced risk of autism associated with folic acid supplements taken near conception, more research is needed to investigate whether this association is casual,” she said. “Interestingly, both studies reported...a nearly 40 percent reduction in risk for autism.”
The number of children with autism spectrum disorders in the United States rose to one in 88 in 2012, up from one in 110 in 2006, according to the Centers for Disease Control and Prevention (CDC).
Dr. Jennifer Ashton, a senior medical contributor to ABC News, said she tries to help the patients in her OB/GYN practice to weigh the benefits and risks of things that might affect their pregnancies, such as medications, chemical exposure, or consuming certain foods. She said she knows from her own pregnancy how confusing and frightening it can be, and she aims to alleviate some of that by reassuring mothers that fetuses are resilient.
“Society can sometimes do a really good job of laying blame and guilt, and when there is no medical proof that it is the mother’s fault,” Dr. Ashton said. “I usually tell women pregnancy is no different than parenting. There are never 100 percent guarantees of anything.”
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