Researcher looks for link between gene and pregnancy weight gain

Even before last week’s release of revised pregnancy weight-gain guidelines, a researcher at the University of Rochester School of Nursing was studying why certain women gain more pounds than others and searching for ways to help them maintain healthy weights.

Susan Groth, Ph.D., R.N., W.H.N.P.-B.C., assistant professor at the School of Nursing, is looking at the relationship between women’s physical activity levels during pregnancy and the amount of weight gained. She wants to find out if these levels are impacted by the presence of a particular gene.

“The hope is that if this study proves there is indeed a link, then we can tell women how much physical activity they need to do to counter the genetic component and keep their weight gain at a healthy point leading to better outcomes for them and for their babies,” said Groth.

Excessive weight gain during pregnancy can have adverse effects including higher risk for cesarean section, gestational diabetes, high blood pressure for the mother, and large-for-gestational-age babies. Babies born to mothers who have excessive weight gain are also more likely to suffer obesity down the road. These health problems along with the rise in obesity in America led the Institute of Medicine (IOM) to issue new guidelines. Of particular note is the IOM’s recommendation that women who are obese at the start of their pregnancies limit their gain to 11 to 20 pounds.

“The new IOM guidelines are important in providing guidance in advising all women on the appropriate weight gain that leads to the best maternal and fetal outcomes, balancing benefit for both,” said Groth. “For my research, the addition of guidelines for obese women provides a structure that we did not have for them until these came out.”

Groth’s study focuses specifically on the weight gain of African American women, a demographic shown to have the highest prevalence of obesity. Based on data from the 2003-2004 National Health and Nutritional Examination Survey, 62 percent of all women were overweight or obese, but 82 percent of all African-American women were overweight or obese. The gene that Groth is studying is carried by 70 percent of African-American women.

“A maternal consequence of excess gestational weight gain is an increase in postpartum weight retention which can contribute to long term obesity,” said Groth. “This is of particular concern for African-American women because they are at high risk for long-term weight retention following pregnancy and also have a tendency to gain additional weight in the 3 to 12 months following pregnancy.”

Groth’s study, which began enrolling participants in October 2008, follows women through pregnancy up until six months after delivery measuring weight changes, diet and activity levels, as well as energy expenditure while lying in bed. “In the end, we’d like to be able to help women come out of pregnancy the healthiest they can be and with babies born at their optimum potential,” said Groth.