Diabetes Screening During and After Pregnancy: We Must Do Better

New screening criteria translated to higher rates of gestational diabetes; fewer than 20% of women with gestational diabetes underwent postpartum diabetes testing.

About 10% of women with gestational diabetes mellitus (GDM) develop postpartum diabetes; thus, the American College of Obstetricians and Gynecologists recommends that all women with GDM be tested 6 to 12 weeks postpartum. Investigators used test results from Quest Diagnostics — a large U.S. clinical laboratory that sponsored the study — in 924,873 pregnant women (age range, 25–40) to assess screening rates for and prevalence of GDM and postpartum diabetes.

Rates of GDM screening with oral glucose tolerance tests (OGTTs; 50-g glucose screen or 75-g or 100-g confirmatory tests) ranged from 71.3% in whites to 77.5% in Asians. Compared with women who weighed 100 to 124 lbs, those who weighed >275 lbs were 348% more likely to test positive for GDM. Despite having the lowest mean weight (137 lbs), Asians had the highest GDM positivity rate (9.1%); blacks (mean weight, 175 lbs) had the lowest rate (4.4%). When the new International Association of Diabetes and Pregnancy Study Groups screening criteria (Diabetes Care 2010; 33:676) were applied (1 abnormal value after a 75-g 2 hour OGTT) instead of Carpenter-Coustan criteria (2 abnormal values after a 100-g 3 hr OGTT), the overall positivity rate rose from 4.9% to 5.3% (i.e., 3843 vs. 7268 women with GDM). Only 19.3% of women with GDM underwent postpartum diabetes screening within 6 months of delivery. In 1.4% of these women, diabetes was confirmed.

Comment: A substantial proportion of women in this study did not receive appropriate GDM testing. For clinicians (such as myself) who do not see many Asian patients, the data on GDM rates in Asian women might be surprising. Regardless of race, postpartum screening rates were dismal in women with GDM — a finding that might be attributable to lack of access to nonobstetric primary care. Strong efforts should be directed toward promoting the International Association of Diabetes and Pregnancy Study Groups screening criteria, emphasizing the advantages of 75-g 2 hour OGTTs, and stressing the importance of postpartum testing in women with GDM.

— Wendy S. Biggs, MD

Published in Journal Watch Women’s Health January 13, 2011