It has long been recognized that the diagnosis of gestational diabetes mellitus (GDM) identifies a population of young women at high risk of developing Type 2 diabetes (T2DM) in the future. In recent years, however, a series of studies have revealed that antepartum glucose tolerance screening, a standard element of current obstetrical care instituted for the purpose of detecting GDM, may provide previously-unrecognized insight into a woman's future risk of metabolic and vascular disease. Indeed, it has emerged that in fact any degree of abnormal glucose tolerance detected on antepartum screening (i.e. not just GDM) predicts an increased future risk of pre-diabetes and diabetes, one that is proportional to the severity of dysglycemia observed in pregnancy. In addition, in the years following the index pregnancy, women with a history of GDM exhibit an enhanced cardiovascular risk profile and ultimately an increased incidence of cardiovascular disease (CVD), risks that may similarly extend to women with milder gestational glucose intolerance as well. Thus, by providing a unique window to a woman's risk potential for future metabolic and vascular disease, glucose tolerance testing in pregnancy, as currently practiced, may offer an opportunity for the early identification of high-risk individuals prior to the onset of clinical disease. Ultimately, the insight so derived may inform strategies for postpartum surveillance, risk factor modification, and disease prevention that may eventually lead to a reduction in the burden of T2DM and CVD in women.