More women worldwide are developing gestational diabetes
Gestational diabetes, which is diabetes that develops in pregnant women, can mean serious problems for mom and baby. Mothers may need a cesarean delivery; babies can be born too large. And the risk of later developing type 2 diabetes is greater for both moms and babies. Though gestational diabetes is more prevalent than it used to be—current estimates say nearly a quarter of a million pregnant women in this country develop the condition each year—experts are not in agreement about how to diagnose it.
Michelle Williams, an epidemiologist and professor at the Harvard School of Public Health, is a pioneer in gestational research. She spoke with us about the risk factors for developing the disease and the diagnostic controversy in the medical community.
What group is most likely to develop gestational diabetes?
Michelle Williams: Asian and Pacific Islander women have the highest rates of developing gestational diabetes. Although their rates aren’t the highest, African-American women who do develop gestational diabetes have a higher rate of developing type 2 diabetes in later life than other groups.
Is high maternal weight linked to an increased rate of gestational diabetes? What about maternal age?
MW: There is a substantially higher risk [linked to maternal weight]; it increases exponentially with the weight of the mother. Even before she’s pregnant, an obese woman has lower insulin sensitivity. Studies show a nearly 60-fold increase in the development of gestational diabetes in women older than 40. Another big risk factor is a sedentary lifestyle. Other common risk factors include family history of diabetes, non-white race and cigarette smoking.
Why is there controversy over diagnosing gestational diabetes?
MW: Studies show diagnosis and treatment improve maternal and fetal outcome. But there’s still controversy, largely around how best to screen—which protocol to use, a one-step versus a two-step protocol. (In the U.S., the two-step approach is used; in Europe, the one-step approach is widely used.) The one-step approach could double or triple the frequency of women diagnosed with gestational diabetes. What are the consequences on the health-care system of 500,000 women with gestational diabetes? They would need nutritional counseling; their blood glucose would need to be monitored. Overnight, it would overwhelm the system as it exists. But having a child develop in a toxic, hypoglycemic environment is not good, either. Could we be over diagnosing and overtaxing the system? Conversely, is a fetus developing in any hypoglycemic environment bad? These are hard questions to have to deal with.
What can we do to prevent gestational diabetes?
MW: One study showed that 30 percent of all gestational diabetes could be prevented if adult weight gain was avoided. We encourage women to consume diet rich in fruits and vegetables, high in fiber, lower in saturated fats. Women who are physically active both before pregnancy and during pregnancy have a significantly reduced risk of developing gestational diabetes. So lifestyle intervention programs are important, but women need supportive counseling.
How are your research methods different from your peers?
MW: I strive to identify gaps in existing literature, and expand the literature by searching for and confirming novel outcomes in the research.