New study backs parent age-autism link

New study backs parent age-autism link

Last Updated: 2008-12-12 9:12:21 -0400 (Reuters Health)

By Anne Harding

NEW YORK (Reuters Health) - Advanced parental age does indeed appear to boost autism risk in children, and the risk is seen with both mothers and fathers, new research shows.

"What we found was that actually it's both parents age, and when you control for one parent's age you still see the effect of the other parent's age, and vice versa," Dr. Maureen Durkin of the University of Wisconsin School of Medicine and Public Health in Madison, the lead researcher of the study reported in the American Journal of Epidemiology, told Reuters Health.

The findings may offer clues to understanding the causes of autism and why it's on the rise, but they shouldn't be used to guide family planning decisions, Durkin said. Even though the oldest child born to two older parents is three times as likely to be autistic than a middle or youngest child with younger parents, she explained, there's still a 97 percent chance that the higher-risk child will be perfectly fine. "The vast majority of children don't develop autism," she emphasized.

Several studies have suggested links between a father's age or the age of both parents and a child's likelihood of having autism. The current study included twice as many autism cases as any other research on this issue to date, which made it possible to tease out the effects of both maternal and paternal age.

The researchers looked at 253,347 children born in 1994 at 10 sites included in the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network. There were 1,251 children who met standard criteria for an autism spectrum disorder at age 8 for whom information on both parents' age was available.