Gestational hypertension, preeclampsia, and diabetes are all associated with increased risks of poor maternal and perinatal outcomes. Pregnant women with gestational diabetes have been shown in population studies to have increased risk of pregnancy-associated hypertension compared with nondiabetic women. Moreover, pregnant patients with hypertension are at increased risk for developing gestational diabetes mellitus. It has been hypothesized that this association could be due, at least in part, to insulin resistance. Although insulin resistance is a physiologic phenomenon in normal pregnancy, in predisposed individuals this could lead to hyperinsulinemia with the development of gestational hypertension, gestational diabetes mellitus, or both.