Gestational diabetes mellitus (GDM) is a potent risk factor for type 2 diabetes. It occurs in about 4% of pregnant women. Nearly 1 in 5 women with GDM are affected by type 2 diabetes within 9 years after parturition. Previous studies have shown that a minority of women are tested for type 2 diabetes during the postpartum period. It is unclear from previous studies whether women are having postpartum ambulatory physician care visits, whether such testing is being offered at these visits, or how they are being counseled regarding the risk for type 2 diabetes and the need for testing.
This retrospective population-based cohort study evaluated long-term trends for postpartum diabetes testing between women with and without GDM and also evaluated postpartum ambulatory physician care for women who had been diagnosed with GDM. Administrative health care databases were used to identify matching groups of women with and without GDM who delivered between 1994 and 2008 in Ontario. Among the 1,673,469 births occurring during the study period, 47,691 (2.8%) were complicated by GDM. The proportion of women with GDM receiving a postpartum oral glucose tolerance test (OGTT) within 6 months after parturition was determined, stratified by the specialty of the ordering physician. In addition, ambulatory care visits by all women with GDM to physicians from various specialties were recorded for up to 6 months after parturition.
Fewer than 1 in 6 women had received a postpartum OGTT by the end of the study period. Although the absolute proportion of women with GDM tested increased slowly during the 14 years of observation (approximately 0.8% per year), less than 40% received any kind of test that might be used to diagnose diabetes mellitus, and less than 20% received an OGTT. There was no change in testing among women without GDM. Nearly all women with GDM (94%–97%) had postpartum ambulatory care visits to a family physician or obstetrician during the study, but less than 5% had an OGTT ordered by one of these physicians.
These findings show that few women with GDM receive the recommended diabetes test within 6 months after parturition. The absence of testing despite postpartum ambulatory physician visits by virtually all these women represents a missed opportunity to diagnose diabetes in a high-risk population.