The impact of antihypertensive treatment of mild to moderate hypertension during pregnancy on maternal and neonatal outcomes: An updated meta-analysis of randomized controlled trials

Abstract

Currently, there is controversy regarding the treatment of pregnant patients with mild hypertension (blood pressure 140-159/90-109 mm Hg). While guidelines do not recommend this treatment, results from recent clinical trials are supportive of the treatment. This meta-analysis aimed to clarify if active treatment of mild hypertension during pregnancy results in better maternal and fetal outcomes. All of the potentially eligible randomized controlled trials were retrieved through a systematic database search investigating the impact of pharmacological treatment in mild hypertensive patients on maternal, fetal, and neonatal outcomes. Relative risk (RR) and 95% confidence interval (CI) were calculated using a random-effects model. Data from 12 trials comprising 4461 pregnant women diagnosed with mild to moderate hypertension (2395 in the intervention group and 2066 in the control group) were extracted for quantitative synthesis. Antihypertensive treatment was associated with better outcomes in seven out of the 19 analyzed outcomes: Severe hypertension (RR = 0.53; 95% CI = [0.38;0.75]), preeclampsia (RR = 0.71; 95% CI = [0.54; 0.93]), placental abruption (RR = 0.48; 95% CI = [0.26; 0.87]), changes in electrocardiogram (RR = 0.43; 95% CI = [0.25; 0.72]), renal impairment (RR = 0.42; 95% CI = [0.34; 0.51]), pulmonary edema (RR = 0.46; 95% CI = [0.25; 0.84]), and neonatal mortality (RR = 0.72; 95% CI = [0.57; 0.92]). The primary safety outcome of small for gestational age was not different between the treatment group and the control group (RR = 1.12; 95% CI = [0.80; 1.57]). The results of this meta-analysis are in favor of the beneficial impact of pharmacological treatment of mild hypertension on both maternal and neonatal outcomes and without significant adverse events for the fetus.

Keywords: antihypertensive treatment; chronic hypertension; fetal outcomes; gestational hypertension; maternal outcomes.

Figure 1

PRISMA flowchart of the process of study inclusion. PRISMA, Preferred Reporting Items for Systematic Review and Meta‐analysis; RCT, randomized controlled trials.

Figure 2

Pooled treatment effect estimates of antihypertensive treatment in mild hypertension on pregnancy outcomes. 95% CI, 95% confidence interval; ECG, electrocardiogram; IUFD, intrauterine fetal demise; LBW, low birth weight; NICU, neonatal intensive care unit; RR, relative risk; SGA, small for gestational age; VTE, venous thromboembolism.

Figure 3

Forest plot displaying the impact of antihypertensive medications in mild hypertension during pregnancy on (A) severe hypertension, (B) preeclampsia, (C) renal impairment, (D) placental abruption, (E) pulmonary edema, and (F) ECG change based on the type of hypertension included in each trial. 95% CI, 95% confidence interval; ECG, electrocardiogram; MH, Mantel–Haenszel.

Figure 4

Forest plot displaying the impact of antihypertensive medications in mild hypertension during pregnancy on small for gestational age (SGA) based on the type of hypertension included in each trial. 95% CI, 95% confidence interval; MH, Mantel–Haenszel.