Older moms may have options to reduce newborns’ risks

Exercising moms could offset added danger of heart defects, a mouse study shows

Older women who get pregnant face a heightened risk of having a baby with congenital heart defects. But exercise might lower that risk, a study in mice shows.

Researchers designed an experiment to determine what underlies the age-related risk: the age of the mother or the aging eggs she carried. The researchers transplanted ovaries reciprocally between old and young female mice. When the mice gave birth, the age of the eggs didn’t matter, scientists from Washington University School of Medicine in St. Louis discovered. The older moms were still about twice as likely to have newborns with a heart defect even though the moms had the ovaries and eggs from the young mice, the researchers report online April 1 in Nature.

However, if the older female mice voluntarily exercised on a running wheel during their reproductive life spans, this higher risk largely disappeared.  

The findings suggest that there is a maternal biological chain of events that exercise affects and that can be targeted to lessen congenital heart disease risk in offspring, the authors conclude.

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