Women who reported having had a fever during pregnancy were more likely to give birth to a baby who would later be diagnosed with autism spectrum disorder or a development delay, says a major new study. But the babies of women who treated their fevers with medication fared no worse than babies whose mothers recalled having suffered no fevers at all.
The findings, wrote the authors, "suggest that anti-fever medication used to control fever during pregnancy can reduce or eliminate" the apparent link between maternal fever and autism.
The study, by researchers at UC Davis' MIND Institute, was published in the Journal of Autism and Developmental Disorders. It wades into a tempestuous debate over what environmental factors in pregnancy might contribute to autism -- and to an apparent increase in autism over the last several decades. Several studies have yielded conflicting findings over whether a link exists between infections during pregnancy and a baby's risk for autism. Many of those studies, however, have been marred by small population sizes and their reliance on a mother's recall, or medical records, of infection.
The current study, called Childhood Autism Risks from Genetics and Environment (CHARGE), sought to avoid those pitfalls. Researchers enrolled babies and their mothers into the major population study when the infants were between the ages of 2 and 5. Between January 2003 and September 2010, 1,122 babies were enrolled--538 diagnosed with autism spectrum disorder, 163 with developmental delays that were not thought to be autism, and 421 typically developing children. Their mothers were interviewed at length about their pregnancies; whether they were vaccinated against flu; whether and when in their pregnancies they suffered infection, flu, or fevers; and what medication, if any, they took in response.