Got a fever? It may be time for a phone call to your doctor to ask what medication is safe to treat it.
Why? Because women who run a fever during pregnancy appear more likely to have children who are later diagnosed with autism or a developmental delay. But when moms-to-be take medication to bring fever down, their child's risk for autism drops to normal levels, according to a study from the University of California Davis.
Published online in the Journal of Autism and Developmental Disorders, the results come from the Childhood Autism Risk from Genetics and the Environment (CHARGE) study, a large-scale investigation that tracks a diverse population of children aged 2 to 5 years living in California. Mothers of these children filled out questionnaires about whether they had the flu and/or fever during pregnancy and if they took medications to treat their illnesses.
When researchers matched up the moms' answers, results showed that whether or not women had the flu during pregnancy had nothing to do with their child's risk for autism or developmental delay. Fever from any cause during pregnancy, however, was far more likely to be reported by mothers of children with autism (2.12 times higher odds) or developmental delay (2.5 times higher odds). But when moms who developed a fever took steps to control it with an anti-fever medication, their children's risk for autism or a delay dropped to the same levels as children whose mothers never had a fever.
Researchers can't explain this association between fever and autism, but can only speculate that it has something to do with inflammation. Fever is produced by acute inflammation, and researchers think chemicals released in the body when it is inflamed cross the placenta and somehow affect brain development. Other CHARGE studies have found connections between children with autism and moms with diabetes or moms who are obese. Both of these conditions are also linked to inflammation.
"Since an inflammatory state in the body accompanies obesity and diabetes as well as fever, the natural question is: Could inflammatory factors play a role in autism?" asks Irva Hertz-Picciotto, a professor of public health sciences at UC Davis and principal investigator of CHARGE.
Researchers are already planning a follow-up study to answer this question.
What does all this mean for you? These findings don't show that fever in any way causes autism, only that it's a trait some moms whose children are affected by autism have in common. Just continue doing your best to take good care of yourself, such as getting enough sleep and taking prenatal vitamins daily. In fact, here's something that may put your mind at ease: another autism study says adequate amounts of folic acid during pregnancy can reduce a child's autism risk. And folic acid is an immune system booster, meaning that it may also help you not get sick in the first place.