A new, massive study evaluating over 5.7 million children in five countries shows a correlation between parents’ age and the risk of having a child with autism spectrum disorder (ASD). The study determined, older parents, teenage mothers and parents who have a large age gap between them are at a much higher risk of having a child with ASD.
Statistics indicate that the possibility of a child being born with autism spectrum disorder is approximately 1 in 100. The risk for autism was determined to be 66 percent higher in children whose dads were over the age of 50 compared to dads in their 20s, while dads in their 40s were 28 percent more likely to have a child with ASD. Teen mothers were 18 percent more likely to have children with autism than mothers in their 20s. Mothers in their 40s were 15 percent more likely to have children with autism than mothers in their 20s. Dads aged 35-44 who had an age gap of 10 years or more with their partners were also slightly at risk of having a child with ASD.
Some experts believe the increased risk for autism amongst older parents could be related to genetic mutations in the sperm or eggs. Other factors could be environmental exposures, genetic predisposition or complications during pregnancy. Researchers are still trying to understand the increased risk of autism in children born to teenage mothers. One theory is that younger women may experience suboptimal pregnancies because they don’t have access to prenatal care but all correlations require further research.
“Although parental age is a risk factor for autism, it is important to remember that, overall, the majority of children born to older or younger parents will develop normally,” according to the study’s co-author Dr. Sven Sandin.
Research has identified a number of other risk factors as well, including genetics, prenatal inflammation and gut bacteria imbalances, but there is still no known cause for autism.