The study, published online in the American Journal of Obstetrics & Gynecology, also shows the risk increases with each pregnancy that is complicated by gestational diabetes.
There are about 135,000 cases of gestational diabetes in the U.S. each year, and it affects about 4% of all pregnancies, according to the American Diabetes Association.
In the new study of 65,132 pregnant women, those who had gestational diabetes during their first pregnancy had a 13.2-fold increased risk of developing gestational diabetes in their second pregnancy.
Those who had gestational diabetes in their first pregnancy but not their second had a 6.3-fold increased risk for developing this condition during their third pregnancy, and those women who had gestational diabetes in their first and second pregnancies had close to a 26-fold increased risk for developing gestational diabetes in their third pregnancy, the study showed.
"We found that women with gestational diabetes in their first pregnancy are at higher risk of gestational diabetes in their subsequent pregnancies, and the risk for gestational diabetes increases further with subsequent pregnancies," says Darios Getahun, MD, MPH, a research scientist/epidemiologist in the Kaiser Permanente Southern California Department of Research & Evaluation in Pasadena, in an email interview with WebMD.
"This does not mean that women with a history of gestational diabetes have a 100% chance of developing the condition in subsequent pregnancies," he says. "Our findings suggest that women with a history of gestational diabetes in their first pregnancy are at increased risk of developing gestational diabetes in a subsequent pregnancy, compared to women with no prior history of gestational diabetes, and the risk increases with increasing number of pregnancies complicated by gestational diabetes."
Risk Reduction Strategies
Women with a history of gestational diabetes are at increased risk of subsequent gestational diabetes and type 2 diabetes. "Both the American College of Obstetrics and Gynecology and American Diabetes Association recommended that women at risk of type 2 diabetes should be counseled on the benefits of lifestyle modifications, which include diet modification, exercise, as well as weight reduction and maintenance," Getahun says.
That said, the researchers did not have information on lifestyle factors such as weight that may have contributed to women's increased risk for gestational diabetes.
The obesity epidemic may play a role in the high recurrence rate of gestational diabetes seen in this study, as being overweight or obese is a known risk factor for gestational diabetes. "Early identification of at-risk population and timely initiation of postpartum lifestyle intervention may help to prevent gestational diabetes and related adverse pregnancy outcomes," he says.
Risk Is Higher for Some Ethnic Groups
The new study also examined the role that race/ethnicity play in the recurrence of gestational diabetes.For reasons that are not clear, the risk of recurrence of gestational diabetes was higher among Hispanic and Asian/Pacific Islander women, compared with their white counterparts, the study showed.
White rice, a dietary staple among the Asian population, has a high glycemic index. The glycemic index ranks how quickly certain carbs affect blood sugar or glucose levels. Low-glycemic-index carbs produce only small fluctuations in our blood glucose and insulin levels, while high-glycemic-index carbs like white rice can cause spikes.
"Emerging evidence suggests that foods with a high glycemic index may cause elevated levels of serum glucose and insulin, thereby increasing the risk of gestational diabetes," he says. "However, whether the consumption of foods with a high glycemic index predicts the recurrence of gestational diabetes in subsequent pregnancy has not been substantiated."
The new findings "mirror what we are seeing and are consistent with previous studies," says Manju Monga, MD, the Berel Held Professor and the division director of maternal-fetal medicine at the University of Texas Health Sciences Center in Houston.
But that doesn't mean women with a history of gestational diabetes are powerless in the face of their increased risk, she says. "Fifty percent of people with gestational diabetes will develop type 2 diabetes in the next 10 years," she says. "Some women in the study may have undiagnosed type 2 diabetes, not recurrent gestational diabetes."
Women who had gestational diabetes should request screening for type 2 diabetes during their six-week postpartum visit, she says. "If women want to modify their risk for gestational and type 2 diabetes, eat a healthy diet, exercise regularly, and maintain a healthy non-obese weight before your first pregnancy and between pregnancies."