The goal of this study is to compare whether antihypertensive treatment in the postpartum period decreases postpartum hypertension and its associated maternal morbidity, including risk of readmission and healthcare utilization in comparison with no treatment. Women with preeclampsia diagnosed during the antepartum, intrapartum or postpartum period will be randomized to either initiate antihypertensive treatment or standard of care. We hypothesize that postpartum antihypertensive treatment of patients with preeclampsia will decrease risk of hospital readmission, healthcare utilization and the number of severe range blood pressures at postpartum follow-up visits.

This will be a randomized, controlled trial of 300 women with a diagnosis of preeclampsia at any point in their current pregnancy or immediately postpartum. Immediately postpartum is defined as preeclampsia diagnosed after delivery but prior to discharge from the hospital. The diagnosis of preeclampsia will be made using standardized definitions by the American College of Obstetrics and Gynecology. Preeclampsia is diagnosed with new-onset hypertension of blood pressure of greater than or equal to 140 systolic blood pressure or greater than or equal to 90 diastolic blood pressure recorded twice at least four hours apart AND proteinuria, defined as 300mg of protein in a 24hour urine collection or a protein/creatinine ratio of 0.3. If the above blood pressure criteria are met and there is not proteinuria, preeclampsia can still be diagnosed if there is thrombocytopenia with platelet count of less than 100,000, renal insufficiency with creatinine of greater than 1.1 or twice the patient's individual baseline, impaired liver function with AST or ALT twice normal or epigastric/right upper quadrant pain, pulmonary edema, new-onset headache unresponsive to medication, or visual disturbance. All of these findings should not be explained by an alternative diagnosis.

Women will be consented and randomized at the time of their diagnosis, within 96 hours of their delivery. The patients randomized to the treatment group will have an antihypertensive medication prescribed to them. The specific medication will be either labetalol, nifedipine or hydralazine based on allergies and clinically appropriateness of the medication. The patient will be instructed on the dosing, timing, and possible adverse effects. All subject's blood pressures will be monitored per standard postpartum protocols. As per standard practice, all patients with preeclampsia will be asked to return at 7-10 days for a blood pressure check and then again at 6 weeks for a complete postpartum assessment.

Consent of patients, review of blood pressures, data collection and storage, and statistical analysis will be performed at the Medical College of Wisconsin (MCW) through the Maternal Fetal medicine department. Women will be allowed to continue routine antenatal, intrapartum and postpartum care with their primary obstetrician. The research team will follow enrolled patients through the 6-week postpartum follow up.

Inclusion Criteria:

• Age >= 18 years old
• Immediately postpartum (delivered in previous 96 hours)
• Diagnosed with preeclampsia during pregnancy, labor or immediately postpartum
• >30% of blood pressures in the postpartum period were elevated (systolic 140 or higher OR diastolic 90 or higher)

Exclusion Criteria:

• Chronic hypertension with superimposed preeclampsia
• Diagnosis of preeclampsia after discharge from delivery hospitalization
• Persistent severe range blood pressures after delivery requiring initiation of antihypertensive regimen by the care team
• >50% of blood pressures in the postpartum period were normal (systolic less than 140 AND diastolic less than 90)

Statistician will be masked to which group the patient was randomized to.