High blood pressure (hypertension) is one of the most common medical disorders in pregnancy and affects 10% of all pregnancies in the United States, with possible short-term and long-term health complications including increased risk of stroke, and liver, kidney, and heart disease. Management of severe high blood pressure after delivery involves medications to lower blood pressure, strict discharge instructions and close follow- up after delivery. Both oral Nifedipine and oral Labetalol are considered safe agents for the treatment of postpartum high blood pressure, however few studies exist that directly compare the two. The investigators want to conduct this study because they want to compare the effects of oral Nifedipine or oral Labetalol on postpartum hypertension. In this study, subjects will get either oral Nifedipine or oral Labetalol. Subjects will not get both. No experimental drugs or devices will be used.