|GDM is a condition in which women without previously diagnosed diabetes exhibit high blood glucose levels during pregnancy. It is estimated to occur in 5% to 6% of US pregnancies, affecting more than 240,000 births annually. GDM is linked with an increased risk of complications for the mother and child, including maternal high blood pressure, cesarean delivery, and neonatal low blood sugar, and up to half of women who have experienced GDM will develop type 2 diabetes later in life.|
An independent panel recently convened by the National Institutes of Health has concluded that despite potential advantages of adopting a new diagnostic approach for gestational diabetes mellitus (GDM), more evidence is needed to ensure that the benefits outweigh the harms.
The panel recommended following the current two-step diagnostic approach until further studies are conducted.
“The panel believes that there is not presently sufficient evidence to adopt a one-step approach. We are particularly concerned that the adoption of new criteria would increase the prevalence and the corresponding costs of GDM, without clear demonstration of improvements in key short- and long-term outcomes,” says Peter VanDorsten, MD, Lawrence L. Hester, Jr. professor, Medical University of South Carolina, Charleston. “However, given the potential benefits of a one-step approach, resolution of these concerns would change our conclusion.”
The number of women diagnosed with GDM varies with the test criteria used. Tests differ based on whether there is a need for fasting, the grams of glucose given, the number of appointments, and the glucose threshold for diagnosis. Most health providers in the United States use a two-step approach that involves a nonfasting glucose screening of all pregnant women, followed by a glucose tolerance test for a subset.
However, many other countries and prominent organizations, such as the American Diabetes Association, now support a one-step approach for all pregnant women. There is much debate regarding choice of tests and the tradeoffs of each approach. (Click here for more on the association’s view.)
The panel identified certain operational advantages to the one-step approach, including a consistent diagnostic standard across the lifespan and better comparability of research outcomes globally. From a clinical perspective, the one-step approach could promote better standardization of patient care and allow a diagnosis to be achieved within the context of one visit as opposed to two.
Despite potential benefits, there are several concerns about the one-step process. This approach is anticipated to increase the frequency of the diagnosis by two- to threefold, to a prevalence of approximately 15% to 20%.
It is not known whether the additional women identified and their children will benefit from treatment. There is evidence that the labeling of these women may have unintended consequences, such as an increase in anxiety, clinic visits, cesarean delivery, and more intensive antenatal and newborn assessments. And, the additional visits and testing to care for these women would impact their lives and would generate additional health care costs.
The panel suggested that additional research be conducted to resolve key research gaps.
“Pregnancy is the window into the future health of women, and the opportunity to make healthy changes during that critical time should not be missed,” VanDorsten says.
Click here for an updated version of the panel’s draft statement.