Dec. 15, 2014 -- Unborn babies whose mothers get a pregnancy condition called preeclampsia may face a higher risk of having autism spectrum disorder (ASD), a large new study suggests. The odds might also be greater for a developmental delay (DD), when a child doesn't hit milestones tied to language, motor skills, and other key areas within expected timeframes.
Results from the Northern California–based Childhood Autism Risks from Genetics and the Environment (CHARGE) study show that the ASD risk was two times as great and the DD risk five times as great compared to children whose mothers didn't have preeclampsia, a disease marked by high blood pressure during the second half of a pregnancy.
"Since preeclampsia is more common in women who are obese or who have diabetes or chronic hypertension, our findings provide one more piece of evidence supporting efforts to encourage women to maximize their metabolic health through healthy diet and exercise behaviors and medical care prior to conception and throughout pregnancy," says researcher Cheryl K. Walker, MD, of the University of California, Davis, MIND Institute, in Sacramento.
"This is a tremendous public health imperative, as over half of pregnant women in the United States are overweight or obese," she says.
The study was published online Dec. 8 in JAMA Pediatrics.
The analysis included 1,061 children from singleton pregnancies, including 517 with ASD, 194 with DD, and 350 typically developing children.
Among the children with ASD, 7.7% had been exposed to preeclampsia, compared with 5.1% of children with DD and 3.7% of typical children.
Most prior studies of preeclampsia as a risk factor for autism have been small and have yielded "varying results," Walker says. The research overall, though, "supports efforts to reduce preeclampsia," the researchers write.
Max Wiznitzer, MD, says the new study's data has drawbacks. He's an associate professor of pediatrics and neurology at Case Western Reserve University.
The numbers, he says, are "too small" to clearly link preeclampsia with autism spectrum disorders or developmental delays.
“I would be careful in the interpretation of any findings and their significance," he says.
Dr Walker has served on the speaker's bureau for Merck & Co.