Comparative efficacy and safety between intravenous labetalol and intravenous hydralazine for hypertensive disorders in pregnancy: A systematic review and meta-analysis of 19 randomized controlled trials

Abstract

Introduction: Hypertensive disorders during pregnancy elevate the likelihood of unfavorable outcomes for both mother and fetus. In cases of acute hypertension, several pharmacological interventions are available to lower blood pressure, such as hydralazine, a direct arteriolar vasodilator, and labetalol, a combined alpha and beta-blocker.

Objectives: This systematic review and meta-analysis of randomized controlled trials (RCTs) aims to compare the efficacy and safety of intravenous labetalol and intravenous hydralazine for acute hypertensive disorders during pregnancy.

Methods: We systematically searched PubMed, Embase and Cochrane for studies comparing labetalol versus hydralazine in pregnant patients. The primary outcomes were median arterial blood pressure (MABP), diastolic blood pressure (DBP) and systolic blood pressure (SBP). We performed statistical analyses using R 4.1.1. Heterogeneity was examined with the Cochran Q test and I² statistics. Risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI), were computed with a random-effects model.

Results: Nineteen RCTs were included in this meta-analysis, comprising 2,261 patients. Among them, 1,131 (50 %) received treatment with labetalol. There was no statistically significant difference between groups in terms of SBP (MD -1.74; 95 % CI -6.72 to 3.23; p = 0.49; I² = 93 %), MABP (MD -0.72; 95 % CI -2.34 to 0.90; p = 0.39; I² = 0 %), DBP (MD 0.25; 95 % CI -4.72 to 5.21; p = 0.92; I² = 96 %), tachycardia (RR 0.42; 95 % CI 0.15 to 1.18; p = 0.099; I² = 41 %), and placenta abruption (RR 0.42; 95 % CI 0.15 to 1.16; p = 0.093; I² = 0 %). However, labetalol significantly reduced maternal hypotension (RR 0.26; 95 % CI 0.21 to 0.33; p < 0.001; I² = 41 %) compared with hydralazine.

Conclusion: This systematic review and meta-analysis of RCTs found that labetalol and hydralazine were efficient for hypertension disorders in pregnancy. However, labetalol reduced the incidence of maternal hypotension.

Keywords: Hydralazine; Hypertensive pregnancy disorders; Labetalol; Meta-Analysis.