ethnic woman legs standing on bathroom scalesAdults whose mothers were overweight or obese before pregnancy have a dramatically elevated risk of dying from heart disease or stroke, according to a new study presented at the American Heart Association’s Scientific Sessions 2014.

“Excess weight among young women of childbearing age has important implications not only for their own health, but for that of their children as well,” said Michael Mendelson, M.D., S.M., the study’s lead author and a research fellow at the Framingham Heart Study, Boston University and the Boston Children’s Hospital.

Previous studies had shown that people whose mothers were overweight before pregnancy were at higher risk for obesity, diabetes and elevated cholesterol. This study examined whether that translated into higher rates of cardiovascular disease and death.

Researchers analyzed data from 1971 to 2012 on 879 participants (52 percent female, average age 32 when the study began) in the Framingham Heart Study Offspring cohort with information about their mothers’ pre-pregnancy weight status. 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, there were 193 cardiovascular events (coronary heart disease, stroke, heart failure), 28 cardiovascular deaths, and 138 total deaths among the offspring.

Compared with adults whose mothers had not been overweight, the study found that offspring of overweight or obese mothers were at 90 percent higher risk of cardiovascular disease or death.Those offspring’s own risk factors, including obesity, diabetes, high blood pressure and high cholesterol, appeared to account for some of that difference, Mendelson said. The results of this study support efforts to reduce obesity among young women before childbearing years, he added.

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.

Study participants were all Caucasian, Mendelson said, adding that more research would be needed to see whether the findings apply to other racial or ethnic groups. Additional larger studies in other populations are needed to verify these findings; however, these results contribute to a growing body of evidence linking maternal health to later life cardiovascular health in their children.

The Framingham Heart Study is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health in collaboration with Boston University.  Dr. Mendelson is partly funded by Boston University and the Tommy Kaplan Fund, Department of Cardiology, Boston Children’s Hospital.

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