The prevalence of chronic hypertension in pregnancy is estimated at 3%, but this figure is set to increase with rising maternal age and the global obesity epidemic. Cronic hypertension is associated with significantly increased adverse maternal and perinatal outcomes compared with the general pregnant population, therefore optimal antihypertensive treatment needs to be defined.
In a randomized Controlled Trial Louise M et al. conducted the study to compare antihypertensive effect of labetalol and nifedipine in chronic hypertension in pregnancy .
In the trial pregnant women with chronic hypertension (12+0–27+6 weeks’ gestation) were enrolled at 4 UK centers (August 2014 to October 2015). Open-label first-line antihypertensive treatment was randomly assigned: labetalol- (200–1800 mg/d) or nifedipine-modified release (20–80 mg/d). Analysis included 112 women (98%) who completed the study (labetalol n=55, nifedipine n=57). Maximum blood pressure after randomization was 161/101 mm Hg with labetalol versus 163/105 mm Hg with nifedipine (mean difference systolic: 1.2 mm Hg [−4.9 to 7.2 mm Hg], diastolic: 3.3 mm Hg [−0.6 to 7.3 mm Hg]). Mean blood pressure was 134/84 mm Hg with labetalol and 134/85 mm Hg with nifedipine (mean difference systolic: 0.3 mm Hg [−2.8 to 3.4 mm Hg], and diastolic: −1.9 mm Hg [−4.1 to 0.3 mm Hg]). Nifedipine use was associated with a 7.4-mm Hg reduction (−14.4 to −0.4 mm Hg) in central aortic pressure, measured by pulse wave analysis. No difference in treatment effect was observed in black women (n=63), but a mean 4 mm Hg reduction (−6.6 to -0.8 mm Hg; P=0.015) in brachial diastolic blood pressure was observed with labetalol compared with nifedipine in non-black women (n=49). Labetalol and nifedipine demonstrated effectiveness at controlling BP to therapeutic target in women with chronic hypertension in pregnancy (mean BP after randomization: labetalol 134/84 mm Hg versus nifedipine 134/85 mm Hg). No difference was observed in highest brachial BP after randomization to either treatment arm.
It was concluded that Labetalol and nifedipine control mean systolic and diastolic BP to target in pregnant women with chronic hypertension. This study provides support for a larger definitive trial scrutinizing the benefits and side effects of first-line antihypertensive treatment in pregnancy complicated by chronic hypertension.