But in many babies, the bilirubin can't be broken down fast enough, often because their livers are still maturing.
Previous research about a link between jaundice and autism has been inconclusive, Halladay said. A 2005 study involving California children found no evidence of a connection between jaundice and autism. But, more recent studies in Sweden and Denmark did find an association -- but no proof of cause-and-effect -- between jaundice and autism spectrum disorders.
Autism is a developmental disorder that causes problems with social and communication skills and can lead to repetitive or restrictive behaviors. Because the condition has a wide range of symptoms and degrees of severity, autism is now called autism spectrum disorders. About one in 110 children in the United States has the disorder, according to the U.S. Centers for Disease Control and Prevention.
Experts stress that there is likely no one single cause of autism, but multiple genetic and environmental factors may contribute to the disorder.
No one knows exactly why jaundice might have a role in autism, said Dr. Gary Goldstein, a professor of pediatrics and neurology at Johns Hopkins University and president and CEO of the Kennedy Krieger Institute in Baltimore.
"Bilirubin is a neurotoxin that can impact the speech, language and hearing pathways of the brain," he said. "So you can imagine why, if someone was genetically prone to autism, it could be a trigger."
While the new study is "intriguing," it has limitations, Goldstein said. The study authors did not confirm that the children had autism either by looking at their medical charts or doing actual exams. Nor did the researchers have measurements of bilirubin levels in the blood, so there's no way of knowing if the more severe the jaundice, t
All rights reserved