The list seems to keep getting longer. Research has shown exercise improves sleep, reduces cholesterol, reduces some cancers...on and on. Now new research suggests that older women who become pregnant can reduce the risk their child being born with a congenital heart defect simply by exercising.
The risk of heart defects in newborns has been shown to increase with the age of the mother. But a study on mice shows that risk can be greatly reduced simply if the mother is active during pregnancy.
Researchers at Washington University School of Medicine in St. Louis took a few steps to reach this finding. First they took ovaries from older mothers and transplanted them into younger mothers. They also took the ovaries of younger mothers and transplanted them into older mothers.
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They found that defects in the young were higher for those born to older mothers - regardless of whether they had a young uterus within them or not. The track record of babies of younger mothers was consistently better - again regardless of the age of the uterus. This suggested that the increased risk of congenital heart defects is tied to the age of the mother and not the age of her eggs.
Next they tested diets to see if how the mice ate had any apparent effect on the likelihood of defects in their young. They overfed some mice moms with high-fat diets to the point where they became overweight. But they found no corresponding increase in heart defects among their young.
Finally the researchers inserted exercise into the equation.
"We gave the mice access to running wheels, like you would find at a pet store, and we just let the mothers run," said Patrick Y. Jay, MD, PhD, associate professor of pediatrics and an author of the study.
And bingo - the risk of heart defects among offspring of older mothers dropped from 20 percent for sedentary mothers to 10 percent for those who spent time on the running wheel. For younger mothers, the rate of defects stayed about the same, regardless of whether or not they had exercised during pregnancy.
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In other words, older mice mothers who exercise cut the risk of their young having heart defects by half. What's more, the researchers saw no significant difference between mothers who started exercise just three months before their child's birth and moms who had been exercising since their youth.
Granted, the study was on mice, not people, but if the data translates from mice to people (which it often does in science), it offers some hopeful news for mothers over the age of 35 or so who want to improve the chances that their babies are born with healthy hearts.
"This is exciting from a prevention standpoint," Jay said. "If there is something about the mother that is contributing to the risk, independent of the ovary, then we have a much better chance of altering that risk than we would if the problem were solely with aging eggs - simply because adults are easier to treat than eggs or embryos."