A recent study found that expectant mothers who have the flu during pregnancy were twice as likely to have a child with autism, according to published reports.
The correlation reinforces recommendations that pregnant women get the flu shot.
Researchers in Denmark and the U.S. Centers for Disease Control and Prevention interviewed mothers about infections and high fevers during pregnancy and after birth.
Findings were based on the births of 97,000 Danish children between 8 and 14 years of age. Only 1 percent of the children were diagnosed with an autism spectrum disorder, despite the increased risk.
The study found that mothers whose fevers persisted for longer than a week in the third trimester were three times as likely to have a child on the autism spectrum.
The study is being published in the journal Pediatrics.