Study Finds a Fever While Pregnant Increases Autism Likelihood By 40% in Babies

pregnancy autism

According to a new study, fever during pregnancy may increase the risk for autism in a child later on.

Researchers from Columbia University Mailman School of Public Health studied information on nearly 96,000 children born in Norway from 1999 to 2009. Scientists found there were 538 cases of autism spectrum disorder among those in the group. Researchers also discovered that moms of 15,701 reported one or more fevers during their pregnancy, that is similar to rates seen in the United States. Out of those pregnant women who had a fever, 583 gave birth to an autistic child.

Despite the correlation, researchers were unable to define a cause and effect relationship between a fever during a pregnancy and autistic newborns. It was only able to detect a connection between the two.

Columbia’s Dr. Mady Hornig, director of translational research at the Center for Infection and Immunity said, “We had maternal reports of fever at 4-week intervals throughout the entire pregnancy, and we were able to link these data to the autism data we had collected through various methods and also through a patient registry.”

Hornig told CBS News, “We were interested in trying to understand the role of fever because of prior reports with respect to fever, but there were not many. And there had also been many suggestions over the years that various types of infections in mothers during pregnancy had been associated with autism outcomes.”

Hornig argued that every woman who develops a fever during her pregnancy will give birth to an autistic child. Rather, fevers are just a response to an infection and “ it is common during pregnancy. The absolute risk is low. The vast majority of women who get an infection with fever, even flu, are not going to end up having a child with autism,” Hornig told the New Independent.

That said, Hornig says it may just be a deficiency in the mother’s immune system that causes the child to be born autistic.

“There is something in the mother’s immune response that may increase the risk for the infant,” Hornig said. “But it’s not in every mother. We don’t think this is a pathway for autism. We don’t think it’s the only way autism is triggered in children.”