NIH panel supports current diagnostic approach for gestational diabetes

An independent panel of the NIH has determined that the current diagnostic approach for diagnosing gestational diabetes is preferred, according to a press release.

Currently, the United States administers a 50-g glucose challenge test to patients who are pregnant. If the patient’s plasma glucose level, as measured 1 hour after the load, is less than a selected cutoff (130 mg/dL, 135 mg/dL or 140 mg/dL), the patient is not considered to have a diagnosis of gestational diabetes. However, if the glucose level is greater than the cutoff, a 100-g, 3-hour oral glucose tolerance test is given during fasting.

This two-step approach has been criticized by WHO and the International Association of Diabetes and Pregnancy Study Group (IADPSG), whose single-step approach involves a single 75-g, 2-hour OGTT.

“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 corresponding costs of [gestational diabetes] without clear demonstration of improvements in key short- and long-term outcomes,” Peter VanDorsten, MD, panel chairman and the Lawrence L. Hester Jr. Professor in the division of maternal-fetal medicine at the Medical University of South Carolina, said in a press release. “However, given the potential benefits of a one-step approach, resolution of these concerns would change our conclusion.”

According to the conference statement, the panel identified the following research gaps in the diagnostic approach of gestational diabetes:

Develop an approach to diagnosis in the United States that is more consistent with international diagnostic approaches.
Determine whether the additional women categorized as having diabetes by the IADPSG model, who would be considered normal in the two-step strategy, accrue any benefit from treatment.
Conduct cost-benefit, cost-effectiveness and cost-utility analyses to fully understand the resource implications of changing the thresholds for a diagnosis of gestational diabetes.
Conduct research to understand patient preferences and psychological consequences of the diagnosis.
Perform well-conducted perspective cohort studies of the “real world” impact of gestational diabetes treatment on care utilization and practice patterns.
Assess lifestyle interventions during pregnancy that may improve maternal and fetal outcomes in women with gestational diabetes.
Assess the long-term effect of gestational diabetes on future pregnancy planning.
Conduct further study of the long-term metabolic, cardiovascular, developmental and epigenetic effect on offspring whose mothers have been treated for gestational diabetes.
Assess interventions to decrease the subsequent risk for the occurrence of metabolic syndrome, diabetes and CV disease in women with gestational diabetes.

For more information:

National Institutes of Health Consensus Development Conference Statement.