It's also possible, he said, that stress could lead women to do things that are risky to their unborn children, such as changing to a less healthy diet. McCabe said another possibility is that stress alters the DNA of the child in the womb.
In the big picture, Olsen said, "this and other studies tell us to take care of pregnant women who experience severe stressful events shortly before or while they're pregnant."
For his part, McCabe said it's important for pregnant women under stress to talk to their physicians about quitting smoking, which they may increase because they're anxious. "We can't modify whether stress is going to happen in our lives," he said, "but we can modify certain effects of that stress."
The study appeared online March 25 and in the April print issue of the journal Pediatrics. Although it showed an association between maternal stress and risk of congenital heart defects, it did not establish a cause-and-effect relationship.
For more about congenital heart defects, try the U.S. National Library of Medicine.
SOURCES: Edward McCabe, M.D., Ph.D., senior vice president and medical director, March of Dimes, White Plains, N.Y.; Jorn Olsen, M.D., Ph.D., professor and chairman, department of epidemiology, School of Public Health, University of California, Los Angeles; April 2013 Pediatrics
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