According to the American Diabetes Association (ADA), gestational diabetes (GDM) is diagnosed in pregnant women who have not had diabetes, but who have high blood sugar during pregnancy. Approximately 18 percent of pregnant women have the condition.
It is thought that increases in hormone levels during pregnancy, especially those produced by the placenta, are at least partially responsible for the condition. These hormones block the action of insulin on the mother’s tissues, leading to a higher than normal level of blood glucose. Excess glucose can cross the placenta and cause the fetus in turn to produce extra insulin, which can cause accelerated growth and fatness in the baby. Such large babies are considered to be macrosomic (large-sized). If the mother’s blood glucose is not controlled, her macrosomic baby is more difficult to deliver vaginally, may have problems with low blood sugar and breathing, and is at greater risk of becoming obese in childhood or as an adult. In turn, such infants have a higher risk of developing type 2 diabetes.
Further, a woman who has GDM, although it resolves after delivery, will have a seven–fold greater risk of developing type 2 diabetes later in life than women who did not have GDM. Because of these potential problems for both mothers and babies, the U.S Preventive Services Task Force has recently recommended that women who have not previously had diabetes be screened after 24 weeks of pregnancy. The recommended screening test is a two-hour glucose challenge.
To complete the test, after an overnight fast a pregnant woman drinks a solution containing 50 gm of glucose, and her blood glucose level is checked two hours later. If at that time her blood glucose equals or exceeds 130 mg/dL, she would be diagnosed with GDM.
Treatment would be similar to that of nonpregnant women with type 2 diabetes, i.e., increased physical activity, dietary control, and medication if necessary. All of these advisories would take into account the woman’s stage of pregnancy, of course.
In a commentary in MedPage Today, Dr. Sue Kirkman of the University of North Carolina noted that such screening of pregnant women has been the standard of care of the ADA for several years.
My organization, The American Council on Science and Health, has long warned about the risks for mother, fetus and newborn from gaining excessive weight during pregnancy, one of the risk factors for GDM. My own opinion is that having the USPSTF make such a recommendation should help to standardize care in the United States. When the consequences of this condition can be so far-reaching for both mother and baby, it’s important that women take note of the results of the screening test and make every effort to follow treatment guidelines.