A new study in Pediatrics has revealed that the risk of autism in an infant whose older sibling has been diagnosed with the disorder is higher than what scientists previously believed.
The new autism research has found that the risk is close to 19%, up from the 3-14% scientists initially thought. Autism currently affects one in 110 children in the United States, according to the CDC.
“Overall we found this almost 1 in 5 risk, but more like 1 in 4 if the new baby was a boy and 1 in 3 if the family has more than one child with autism,” said researcher Sally Ozonoff, PhD, professor of psychiatry and behavioral sciences at the MIND Institute at the University of California, Davis.
While this new autism news might be disheartening, the information can allow parents for close monitoring of a younger sibling, and help parents make more informed decisions.
The study involved infants who were enrolled in a network known as the Baby Siblings Research Consortium. All 664 infants enrolled in the network had an older brother or sister with autism.
Over the course of three years, the children were evaluated several times, and were given an official diagnosis at 36 months.
At the end of the study, 132 children were diagnosed with an autism spectrum disorder. Of the 132, about 41% were diagnosed with autism and 59% were diagnosed with other conditions on the spectrum, such as Asperger’s syndrome.
Ozonoff says that while that news sounds bleak, not every child in the study was affected. “Remember that overall, over 80% of those babies didn’t have autism,” she says. “The general population risk is under 1%.”