Impact of labetalol versus nifedipine treatment on readmission risk in postpartum hypertension: A randomized controlled trial

Abstract Importance Postpartum hypertensive disorders are a leading cause of maternal mortality. Observational trials suggest outcomes between labetalol and nifedipine may not be similar, and further study is needed to determine optimal postpartum treatment. Objective Compare readmission rates for hypertensive complications between two commonly used antihypertensives in pregnancy, labetalol and nifedipine. Design Open‐label randomized controlled trial comparing labetalol and nifedipine for treatment of postpartum hypertension. The study was conducted from 2022 to 2024. Inclusion criteria: patients with two hypertensive blood pressures (> 140 systolic or > 90 diastolic) 4 h apart during their admission for delivery. Setting Single‐center study in a Level III Obstetric hospital. Participants A total of 3015 patients met the inclusion criteria during the study period and 323 patients over the age of 19 were enrolled and randomized to nifedipine or labetalol. Patients were excluded if already taking two antihypertensive medications and were discharged the day they met the criteria or had contraindications to study medications. Intervention Patients were randomly assigned to nifedipine XR 30 mg twice daily or labetalol 200 mg every 8 h with the remainder of postpartum management at the discretion of their primary provider. Records were reviewed to identify readmissions due to hypertensive complications within 6 weeks of delivery. Main outcomes and measures Our primary outcome was readmission due to hypertensive complications within 6 weeks of delivery utilizing intention‐to‐treat analysis. Results Among 323 patients randomized, the labetalol group ( n = 161) had higher BMI (35.3 vs. 33.5), greater GA at delivery (38 vs. 37 weeks), higher net fluid balance at discharge (−138 vs. −786 mL), and higher prevalence of chronic hypertension ( n = 17 vs. 7) compared to those in the nifedipine groups ( n = 162). After controlling for confounders, incidence of readmission was 88% lower in nifedipine group (1.2% vs. 8.1%); aOR of 0.12 (95% confidence interval [CI] 0.02 to 0.56). The frequency of severe HTN, acute treatment of HTN during hospitalization, use of magnesium sulfate and HTN in the 12 h prior to discharge was similar between groups. Conclusion and relevance Primary outcome was statistically significant and consistent with observational data. Our findings support nifedipine as the first‐line agent for treatment of postpartum hypertension.