Aug. 28, 2007 -- Babies born to mothers with untreated gestational diabetes have nearly double the normal risk of becoming obese during childhood, but treatment to normalize blood sugar also normalizes risk, early research suggests.
The study is among the first to suggest that gestational diabetes is an important risk factor for childhood obesity and that this risk can be reduced by regulating blood sugar during pregnancy, says researcher Teresa Hillier, MD, MS, of the Kaiser Permanente Northwest Center for Health Research.
"High blood sugar during pregnancy results in the baby being overfed in the womb," she tells WebMD. "The result of this overfeeding may be that children become metabolically imprinted or programmed to become obese."
Diabetes-Obesity Link Explored
About 4% of pregnant women in the U.S., or 135,000 women annually, develop gestational diabetes, according to the American Diabetes Association (ADA).
The ADA funded the latest research in an effort to determine whether gestational diabetes plays a role in childhood obesity. The study appears in the September issue of the association's journal Diabetes Care.
The study included 9,439 Kaiser Permanente health plan members who gave birth in Oregon, Washington state, and Hawaii between 1995 and 2000. All the women were screened for gestational diabetes during pregnancy, and their children's weights were recorded between the ages of 5 and 7.
A child's weight during this period is strongly predictive of his or her weight later in life.
Compared with children born to mothers with normal blood sugar during pregnancy, children born to mothers with poorly controlled high blood sugar were 89% more likely to be overweight and 82% more likely to be obese between the ages of 5 and 7.
Conversely, children born to mothers with gestational diabetes that was adequately treated were no more likely to be overweight or obese than children born to mothers with no evidence of gestational diabetes.
Many factors contribute to childhood obesity, and experts agree that the link between gestational diabetes and future weight must be confirmed in more studies.
Pediatric endocrinologist Larry C. Deeb, MD, a spokesman for the ADA, says the study helps make the case for the aggressive treatment of gestational diabetes.
"Most women are screened, but I don't know if women are being treated as aggressively as they should be," he tells WebMD. "'This study suggests that treatment could potentially make a big difference in the child's obesity and diabetes risk later in life."
A Study Participant's Story
Vanessa Hayden of Troutdale, Ore., participated in the study while pregnant with her first child, Samantha, who is now age 7.
Hayden made lifestyle changes and took insulin during the pregnancy after learning she had gestational diabetes.
"At the time my thinking was that I didn't want to have a 20-pound baby, so I was determined to do what it took for my child to be born healthy," she tells WebMD. "I had no idea that what I was doing might be giving my daughter an edge to lower her future risk for becoming overweight."
With a very strong family history of both type 2 diabetes and obesity, Hayden says any edge she can give her children is important. She now has four children between 4 months and 7 years old.
She followed her blood sugar closely with all of her pregnancies and kept it tightly controlled with exercise, healthy diet, and insulin.
Hayden says all four children are "healthy and happy," and she describes her eldest daughter as "scrawny."
"I'm glad to know that what I did at the time may have had something to do with that," she says.