Flu May Increase Autism Risk
November 12, 2012

Flu Could Increase Child’s Risk Of Having Autism

Lee Rannals for redOrbit.com — Your Universe Online

Contracting the flu while pregnant could lead to a higher risk of that child having autism, according to a study published in the journal Pediatrics.

The study included children born in Denmark between 1997 and 2002, and included those with a diagnosis of autism spectrum disorder.

The researchers found that children born to mothers who had the flu during pregnancy or fevers lasting more than a week have a slightly higher risk for autism.

"Our findings are interesting for research purposes, but they should not alarm women who are pregnant," researcher Hjordis Osk Atladottir, MD, PhD, of Denmark´s University of Aarhus, said in a statement. "It needs to be emphasized that around 98% of the women in this study who experienced influenza or fever or took antibiotics during pregnancy did not have children with autism."

No evidence was found for an increase in autism risk among children born to women who had colds, sinus infections, and urinary and genital tract infections during pregnancy. Atladottir said this was reassuring because these are some of the most common infections amongst pregnant women.

The study found that pregnant women who contracted the flu were linked to a twofold increase in a woman's chance of having a child diagnosed with an autism spectrum disorder before the age of three.

Mothers who reported having a fever lasting for more than a week had a three fold increase in having a child with autism.

Altadottir said there is some research in rodents that suggests women's activated immune cells can cross the placenta and affect chemicals in a fetus' brain. However, those findings have not been proven to apply to humans.

"The study is really exploratory, and more research needs to be done to understand how maternal infections, as well as other risk factors, influence the risk of autism spectrum disorders," Coleen Boyle, director of the Centers for Disease Control and Prevention's National Center on Birth Defects and Developmental Disabilities, said in a statement. "We need to have more information to get a better sense of what's going on here."

Pediatrician Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children´s Medical Center of New York, told WebMD that it is important to understand there is no single cause of autism.

"There are many different lines of research that are being pursued, and some will inevitably prove more fruitful than others," Adesman said.

The CDC and American Congress of Obstetricians and Gynecologists recommend pregnant woman ensure they get a flu shot during flu season.

"We don't want women to not take antibiotics or not treat fever if they have the flu," Marshalyn Yeargin-Allsopp, chief of CDC's Developmental Disabilities Branch, told USA Today.

About one in 88 children are diagnosed with autism or a related disorder in the U.S. Although the findings indicate a significant increase in the risk of autism when a pregnant woman has contracted the flu, Paul Patterson, who studies the immune system, told Reuters that the risk still remains low.

"It is also worth emphasizing that even though the risk (of infantile autism) is significantly increased, the risk is still quite low."