Sustained blood pressure control and rebound hypertension after acute antihypertensive therapy for severe preeclampsia: A multicenter randomized trial of intravenous labetalol versus nicardipine

Abstract Background: Severe preeclampsia is an obstetric emergency requiring rapid and safe blood pressure control to reduce maternal and fetal complications. Although intravenous labetalol and nicardipine are used for acute antihypertensive therapy, studies comparing the two first-line agents in severe preeclampsia are limited. This study aimed to compare the effectiveness and safety of intravenous labetalol and nicardipine in pregnant women with severe preeclampsia. Methods: This multicenter, outcome-assessor-blinded randomized controlled trial was conducted in ten hospitals in West Java, Indonesia. One hundred and twenty-three pregnant women with severe preeclampsia were included. The primary outcome was time to target blood pressure (BP). The secondary outcomes included minimum-dose response, dose-escalation response, rebound hypertension, sustained blood pressure control, exploratory (ROC)-derived systolic BP (SBP) cut-off for rebound hypertension, adverse events. Results : Of 123 randomized women, three women allocated to labetalol were excluded due to infusion preparation or dilution error leaving 120 patients for modified intention-to-treat analysis. Labetalol achieved target blood pressure faster than nicardipine [15.50 vs 30.00 min; p = 0.002]. Labetalol was also faster with the minimum dose [11.00 vs 22.00 min; p = 0.003] and after dose escalation [21.00 vs 30.00 min ; p = 0.013]. Rebound hypertension was lower with labetalol [8.3% vs 20.0%; p = 0.067] and sustained blood pressure control was higher [91.7% vs 80.0 %; p = 0.067]. Exploratory ROC analysis identified an SBP cut-off of ≥193 mmHg for rebound hypertension in both groups. Among women with baseline systolic blood pressure ≥193 mmHg, rebound hypertension occurred less frequently with labetalol than nicardipine [17.6% versus 45.5%]. Baseline SBP showed good discrimination in the nicardipine group [AUC 0.839 ; p < 0.001], but not in the labetalol group [AUC 0.644 ; p = 0.291]. No hypotension, tachycardia, headache, nausea/vomiting, or fetal bradycardia was observed. Dizziness occurred in one labetalol recipient and two nicardipine recipients. Conclusions : Intravenous labetalol achieved faster target BP control than nicardipine, with comparable short-term maternal and fetal safety. Women with systolic blood pressure ≥193 mmHg, particularly those receiving nicardipine, may require closer post-target blood pressure monitoring. Trial registration : ISRCTN registry, ISRCTN76310309, registered on 16 September 2026. Retrospectively registered.