Gestational diabetes is a type of diabetes that is first diagnosed
during pregnancy. It was once believed that the harm associated with
this type of diabetes disappeared after pregnancy, but this is not
true. It is important to know about gestational diabetes both before
pregnancy, because of the potential harm to mother and baby, and after
pregnancy, because of the possibility of future health issues for the
About 135,000 new cases of gestational diabetes occur each year in the United States, affecting about 4 percent of all U.S. pregnancies. The number of women who develop gestational diabetes varies based on race and ethnicity; for example, African American women are at greater risk of having gestational diabetes than Caucasian women.
Although it is not known exactly why some women develop gestational diabetes, there are certain circumstances that can increase the risk for gestational diabetes. Therefore, it is important for us to know about these risks.
Some of these risk factors cannot be changed, such as a family history (in parents, brothers or sisters) of type 2 diabetes; belonging to a racial or ethnic group known to be at high risk for developing diabetes, such as African Americans, Hispanics, Native Americans or Asians; and being pregnant when older than 35 years of age. Fortunately, there are also risks that can be changed, such as being overweight or not being physically active enough.
An obstetrician or other health care provider will usually test for gestational diabetes between the 24th and 28th weeks of pregnancy. Some health care providers may test earlier in pregnancy if there is concern that the woman is at high risk for gestational diabetes.
Testing for gestational diabetes involves drinking a sugary drink and then having a blood test an hour later. Based on the result, another test may be needed to make the diagnosis. If a woman is found to have gestational diabetes, it can be managed successfully with close blood sugar testing, diet and physical activity (after discussion with health care provider), and medications if necessary.
Working closely with one’s health care providers, including nutritionists and diabetes educators, can lead to a healthy pregnancy and delivery. However, after delivery, careful attention should still be given to one’s health because of the risk of developing type 2 diabetes and heart disease.
Research has shown that women with gestational diabetes have an increased risk of developing diabetes in the future. For example, one study showed that as many as half of the women with gestational diabetes developed type 2 Diabetes in the five years after that pregnancy. Studies have also shown that after gestational diabetes, women have a greater risk of heart disease than women who do not have gestational diabetes.
Because there is little information on heart disease risk in African American women after gestational diabetes, we at Brigham and Women’s Hospital are dedicated to learning more about what can be done to prevent the harmful effects of gestational diabetes on the blood vessels and heart disease risk.
For more information on gestational diabetes, please speak with your health care provider. You can also refer to the American Diabetes Association Web site: www.diabetes.org/gestational-diabetes.jsp.
Dr. Rhonda Bentley-Lewis is working with Dr. Florence Brown, a physician at Beth Israel Deaconess Medical Center and Joslin Diabetes Center, on a study to understand the heart disease risk in women who have gestational diabetes. This research is supported by a grant from the Harvard Medical School Center of Excellence in Women’s Health. Please refer to our ad on this page to learn more about this research.