Autism may be linked to male circumcision, according to a new study in Denmark, the Daily News reported on Wednesday.
Boys who had a circumcision before turning 5-years-old had their chances of developing autism double in comparison to boys who weren't, data from a study of 340,000 Danish boys showed.
The severe pain of the procedure may be to blame, though the relation is not clear.
"The small child's pain could be significant to the later development of autism," said study leader Morten Frisch, consultant and senior investigator in epidemiological research at Statens Serum Institute and adjunct professor of sexual health epidemiology at Aalborg University - both of which are in Denmark.
Previous research had shown that babies who undergo painful procedures and spend long periods of time in intensive care due to being born prematurely show changes in pain perception later on in life. These same symptoms are present in children with autism.
But professor Carsten Obel from the Department of Public Health at Denmark's Aarhus University said it's not just one factor that leads to autism.
"There could easily be some other explanations for the connection found by the study," he said, according to Science Nordic. "There could easily be some other explanations for the connection found by the study."
The professor also noted that there are differences in people who circumcise their baby boys while others don't, which could relate to a risk of developing autism.
"Now that the suspicion has been raised we need to get to the bottom of it and determine for sure whether or not circumcision can be related to autism," Obel said.
