Children of mothers who contract the flu or have a prolonged fever while pregnant may have a very slight increased risk of developing autism spectrum disorder, a new study suggests.
However, women who have had lasting fever or the flu during pregnancy should not be overly concerned by these results, as the risk seen was extremely small.
Mild infections were not associated with an increased risk of autism, Danish researchers found. Antibiotic use was associated only with a very low, speculative risk, according to the study published online Monday and in the December print issue of Pediatrics.
The "study is purely explorative and it is far too soon to suggest any clinical implications," said study lead author Dr. Hjordis Osk Atladottir, of the Institute of Epidemiology and Social Medicine at University of Aarhus.
Having an infection triggers the body's immune system, setting off a reaction intended to thwart the danger.
This is good when it comes to defending the body, but studies have suggested that activation of the mother's immune system may harm a fetus' neurodevelopment.
For this study, researchers asked mothers of almost 100,000 children born in Denmark between 1997 and 2003 about their history of infection, influenza and antibiotic while pregnant.
Children of mothers who reported having the flu while pregnant were twice as likely to develop autism. Having a fever for a week or more was associated with triple the risk.