Pregnant women who are on the fence about whether to get a flu shot this season may want to talk to their doctor about new research suggesting it could help prevent autism in their children.

A study out Monday has found that getting the flu or having a fever during pregnancy may be linked to a higher risk of autism in children. Worrying news, of course to women who are already on alert for everything from their diet to their mental health.

Researchers studied the records of 96,736 children who were born in Denmark between 1997 and 2003. Their mothers were asked about infections and fevers they suffered during pregnancy or just after giving birth. They were also asked about whether they'd taken antibiotics during that period. They found no link between common maternal infections, like respiratory, urinary tract or genital infections, and a child's risk of autism, according to a release from the journal Pediatrics, which published the article online Monday.

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But when it came to the flu, they did find an association.

"Children whose mothers reported influenza during pregnancy had twice the risk of being diagnosed with autism spectrum disorder before age 3, and children whose mothers had a fever lasting more than a week during pregnancy had a threefold risk of autism."

They also found a small increased risk for autism among children whose mothers used antibiotics during pregnancy, according to the release.

Overall, 976 of the children were later diagnosed with an autism spectrum disorder – about 1 per cent, reports Maggie Fox of NBC News.

According to the American Academy of Pediatrics, new data released this year shows that 1 in 88 children have been diagnosed with autism spectrum disorder, a 23-per-cent increase in the past two years.

"Autism spectrum disorders (ASDs) are a group of related brain-based disorders that affect a child's behaviour, communication and social skills. These disorders include autistic disorder, Asperger syndrome and pervasive developmental disorder – not otherwise specified (PDD-NOS)," explains the academy's site.

The study adds to ongoing research that suggests in "at least some cases, something is going on with a mother's immune system during pregnancy that affects the developing child's brain," Fox reports.

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Still, researchers say there's more work to be done to figure out exactly what the link is and how it works – and that the overall risk of the flu or fever on autism rates appears low.

"It is important to bear in mind that when you look at the absolute numbers, we see that around 99 per cent of women reporting to have had influenza or fever during pregnancy, do not have children with ASD," Dr. Hjordis Osk Atladottir of the University of Aarhus in Denmark told Fox by e-mail. "We do not want pregnant women to worry."