Raising a child with autism may take a deeper toll than previously thought with new research suggesting that such moms face a heightened risk of heart disease.

Mothers of kids on the spectrum who have chronic stress were more likely than less-stressed moms of neurotypical children to experience cardiovascular risk factors.

The findings reported this month in the journal Brain, Behavior and Immunity come from a study looking at 31 moms of kids with autism and 37 mothers of typically-developing children. All of the women were nonsmokers between the ages of 20 and 50 and both groups included moms of similar ages with comparable body mass indexes and other risk factors.

Among mothers of kids with autism, 30 percent had high levels of what’s considered “bad” cholesterol compared to 8 percent of other moms.

Meanwhile, those with a child on the spectrum generally had lower levels of progenitor cells which are believed to provide a protective effect against plaque buildup in the blood vessel linings that can trigger heart attack and stroke.

“Even knowing the challenges these mothers face, we were surprised by the differences in cardiovascular risk,” said Kirstin Aschbacher of the University of California, San Francisco, who led the study.

Despite the greater risk faced by moms of those with autism, researchers found that little changes can make a big difference. Mothers who reported a greater number of positive interactions with their families during a given week had higher levels of protective cells, the study found.

“For all parents studied, those small daily interactions with their child, positive or negative, predicted the level of protective progenitor cells. That means that even if you are a caregiving parent, your daily responses may protect you from risk,” said Elissa Epel of the University of California, San Francisco and a senior author of the study. “Parenting support groups, or classes that teach stress resilience such as mindfulness, can help parents feel less shame and self-blame about their child’s behavior, and help them focus more attention on the small positive interactions.”