Screening for gestational diabetes mellitus (GDM) is important to the health of mother and offspring in preventing pregnancy-related complications. GDM, which occurs when pregnant women without a history of diabetes develops high blood glucose levels, increases the lifetime risk for developing one or several several chronic conditions, including type 2 diabetes, metabolic syndrome, and cardiovascular disease — the leading cause of mortality among women.
It is recommended that all pregnant women be screened for the condition between the 24th and 28th week of pregnancy. Women who have risk factors for GDM may have this test earlier in pregnancy, offered by board-certified physicians in the UF Health Maternal-Fetal Medicine division.
Two diagnostic approaches are preferred for screening. UF Health physician Anthony R. Gregg, M.D. in the UF Department of Obstetrics and Gynecology, and colleagues recently completed a review of data on nearly 900 pregnant women at UF Health Shands Hospital in Gainesville, FL to evaluate the screening outcomes relative to each of method. The “one-step” screening involves a single administration of glucose that is monitored over 2 hours and requires patients to fast. Alternatively, the 2-step selective approach involves two oral glucose tests: one administered universally, and a second only to women who exceed a designated glucose cutoff following the first round of testing. For both, the diagnosis of GDM is made when certain diagnostic criteria are met.
The researchers noted that the single-step method identified significantly more individuals with GDM — in context with the worldwide increases in obesity and diabetes rates. The findings are in agreement with the International Association of Diabetes and Pregnancy Study Groups (IADPSG) and the World Health Organization, who recommend this approach as the preferred form of testing.
But supporters for the two-step method, including the National Institutes of Health, note that the increase in the incidence of GDM diagnosed by the single step method would “have significant impact on the costs, medical infrastructure capacity, and potential for increased medicalization of pregnancies” previously categorized as normal. More long-term outcome studies are needed to establish a “gold standard” approach to diagnose GDM that can demonstrate clear improvements in key short- and long-term metrics.
Ogunleye O, Davidson K, Gregg A, Egerman R. Gestational diabetes: two-step glucose tolerance test compared with one-step glucose tolerance test. Obstet Gynecol. 2014 May;123 Suppl 1:163S-4S.