THURSDAY, Nov. 20, 2014 (HealthDay News) -- Overweight or obese women who get pregnant are much more likely to have a child who suffers from heart disease as an adult, new research suggests.
But it looks like environment may play a greater role than genetics in that trend, the researchers added.
"Mothers who are overweight teach behaviors, and those behaviors are passed on," said study author Dr. Michael Mendelson. He is a research fellow at the Framingham Heart Study, Boston University and the Boston Children's Hospital.
"There's been mounting evidence that maternal health before going into pregnancy has implications for her offspring," Mendelson added. "This shows there are a lot of good reasons to focus on the health and weight of young people before they go on to have children."
Researchers analyzed data on 879 participants in the Framingham Heart Study, the classic long-term, ongoing study of the heart health of people living in the town of Framingham, Mass.
About 10 percent of the mothers had been overweight, with a body-mass index of 25 or higher before pregnancy. That translates to a weight of 145 pounds or more for a 5-foot-4 woman.
During the 41-year span of the data, from 1971 to 2012, there were 193 cases of heart disease, stroke or heart failure, 28 heart-related deaths, and 138 total deaths among all the children.
Compared with adults whose mothers had not been overweight, the study found that offspring of overweight or obese mothers faced a 90 percent higher risk of cardiovascular disease or death.
Even though the children's own risk factors accounted for some of the difference, Mendelson said there could also be a genetic component at play.
The children might be affected in their womb by their mothers' poor health, or both mother and child might have a genetic predisposition for heart problems and obesity, he explained.
But Dr. Martha Daviglus, a professor at the University of Illinois College of Medicine and executive director of the Institute for Minority Health Research, said she thinks maternal overeating both affects the child in the womb and then creates a bad example as the child grows up.
"It's not genetics. It's mostly environmental," Daviglus said. "This transmission would not have happened if the mothers were able to control their weight and their food."
Currently, more than one-half of pregnant women in the Unites States are overweight or obese, according to online statistics from the American Congress of Obstetricians and Gynecologists.
Mendelson said larger studies in other populations are needed to verify these findings, but added that the results highlight the need for efforts to reduce obesity among young women both before and during their childbearing years.
Visit the U.S. National Institutes of Health for more on obesity during pregnancy.