Mothers who recalled having a fever during pregnancy were twice as likely to have a child with autism as were mothers who did not recall such fevers, according to newly published research. However, those mothers who reported taking medication to reduce their fevers did not show this increased risk.
The new findings appear online in the Journal of Autism and Developmental Disorders. They come out of a larger, ongoing investigation known as the Childhood Autism Risk from Genetics and the Environment (CHARGE) Study. CHARGE receives funding from the National Institute of Environmental Health Sciences, the U.S. Environmental Protection Agency, UC-Davis’s MIND Institute and Autism Speaks.
"Our study provides strong evidence that controlling fevers while pregnant may be effective in modifying the risk of having a child with autism or developmental delay," says Ousseny Zerbo, Ph.D., the study’s lead author. "We recommend that pregnant women who develop fever take [fever-reducing] medications and seek medical attention if their fever persists." Zerbo was with the University of California at Davis when he helped conduct the study. He now works for Kaiser Permanente.
CHARGE includes an ethnically diverse population of children ages 2 to 5 years. In the current study, 538 children had autism. Another 163 children had developmental delay but not autism. And 421 were developing typically. Their mothers completed questionnaires that included questions about illness and medication use during pregnancy.
Fever during pregnancy was reported twice as often by mothers of children with autism compared to mothers of typically developing children. It was 2.5 times more frequent than "typical" among mothers of children with developmental delay. However, when the researchers looked at those mothers who reported taking medication for their fevers, these were no more likely to have a child with autism or developmental delay than were mothers who reported no fever.
Another recent study based on CHARGE data found that mothers who were obese or diabetic had a higher likelihood of having children with autism, notes Irva Hertz-Picciotto, Ph.D., CHARGE’s principal investigator at UC Davis. The common link may be inflammation, she says. Fever is produced by acute inflammation. Obesity and diabetes are associated with chronic inflammation.
“Autism Speaks has funded several studies focused on understanding the role of inflammation during pregnancy on fetal development and autism,” says Autism Speaks Chief Science Officer Geri Dawson, Ph.D. “We are trying to understand the exact mechanisms by which inflammation affects brain development.”
Autism Speaks-funded studies on prenatal risk factors include a number of CHARGE projects, as well as other investigations. Readers can explore these and other Autism Speaks research grants using this website’s Grant Search. Also see “Perspective on Maternal Obesity and Autism” in the Autism Speaks Got Questions? blog.