Danish researchers reveal link between autism and influenza and fever
A new study from the University of Aahrus reveals women who have influenza during pregnancy have twice the risk of a child being diagnosed with autism spectrum disorder before the age of three. Researchers also found have a fever during pregnancy that last longer than a week have a three-fold risk of their child having autism and a small increased risk for autism by using antibiotics during pregnancy.
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Dr. Hjordis Osk Atladottir, Department of Public Health, Institute of Epidemiology and Social Medicine at the University of Aahrus, lead author of study stated "I really want to emphasize that this is not something you should worry about," according to Reuters. Researchers say that due to the methodological limitations of study, these findings are due to chance and further research is needed.
Dr. Hjordis Osk Atladottir and colleges examined data from the Danish National Birth Cohort that enrolled 101,033 pregnant women between 1997 and 2003 in which 96,736 children were born.
Researchers interviewed participating women by telephone at 17 and 32 weeks' gestation and again when the child was 6 months old. The women were asked about common infections that included influenza, respiratory tract infections, antibiotic use and fevers.
Researchers found no association between common maternal infections like respiratory infection, urinary tract infection or genital infections and a child’s risk of autism. However, mothers that reported having influenza during pregnancy had a two-fold risk for their child to be diagnosed with autism before the age of three and mothers who had a fever during pregnancy that lasted longer than a week had a three=fold chance that their child would receive a diagnosis of autism.
Researchers also found a small elevated risk for autism when antibiotics were used during pregnancy such as sulfa drugs for bacterial infections and penicillin. According to researchers the antibiotics by themselves may have some sort of effect or it could just be due to chance.
Among the babies whose mothers had influenza during pregnancy 0.87% were diagnosed with infantile autism compared to the rate of 0.4% among children in general
Dr. Coleen A. Boyle, PhD, MSHyg, Director of the National Center on Birth Defects and Developmental Disabilities at the CDC stated "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.” "We need to have more information to get a better sense of what's going on here."
The CDC says pregnant women need a flu shot. The flu shot given during pregnancy has been shown to protect both the mother and her baby up to six months. Flu shots have not been shown to cause harm to pregnant women or their babies. It is very important for pregnant women to get the flu shot.
This study will be released today online in the journal Pediatrics.
This year a team of researchers from UC Davis found that mothers who had fevers during pregnancy were more than twice as likely to have a child with autism or developmental delay.
Researchers analyzed data from case groups of 538 children with autism spectrum disorder (ASD) and 163 with developmental delays (DD) and 421 children for controls.
Exposure information was obtained by telephone interviews, and outcomes were clinically confirmed.
Researchers found neither ASD nor DD was associated to influenza but both were associated to maternal fever during pregnancy.
The study was published online in Journal of Autism and Developmental Disorders, May 5th, 2012.
According to the CDC the latest estimates reveal one in eighty-eight children have some form of autism spectrum disorder.