Maternal ethnicity and its impact on the haemodynamic and blood pressure response to labetalol for the treatment of antenatal hypertension

Abstract

ObjectiveBlood pressure (BP) control outside pregnancy is associated with a reduction in adverse cardiovascular events, and in pregnancy with improved outcomes. Outside pregnancy, there is evidence β-blockers are less effective in controlling BP in black populations. However, in pregnancy, labetalol is recommended as a universal first-line treatment, without evidence for the impact of ethnicity on its efficacy. We sought to compare haemodynamic responses to labetalol in black and white pregnant patients.MethodsThis was a prospective observational cohort study in a London teaching hospital. Maternal haemodynamics were assessed in 120 pregnant women treated with labetalol monotherapy. Measurements were taken at presentation, 1 and 24 h after treatment. Participants were monitored regularly until delivery. Statistical analysis was performed by multilevel modelling.ResultsBoth groups exhibited similar temporal trends in haemodynamic changes over the first 24 h following labetalol. Both showed a reduction in BP and peripheral vascular resistance within 1 h and in heart rate after 24 h. There was no change in cardiac output and stroke volume in either group. BP control (<140/90) was achieved at 1 h in 79.7% of the white and 77% of the black cohort. At 24 h, control was achieved among 83.1% and 63.9%, and up to the immediate intrapartum period control was achieved in 89.8% and 70.4% of white and black patients, respectively.ConclusionsThere is no difference in the acute haemodynamic changes and hypertension can be controlled throughout pregnancy with labetalol monotherapy in excess of 70% pregnant black and white patients.

Longitudinal hemodynamics in acute phase of treatment with labetalol in hypertensive pregnant women to predict need for vasodilatory therapy

“…Black participants in our study were indeed less likely, compared with white participants, to have their BP controlled with labetalol monotherapy. In this study, and in our previous work, however, the majority of black hypertensive patients did nevertheless have their BP controlled with labetalol up to delivery. This suggests that the upregulation of the renin–angiotensin system in pregnancy attenuates the ethnic variation in beta‐blockade response seen in non‐pregnant populations, and that ethnicity should therefore not be used as the sole determinant to guide prescriptions in hypertensive pregnancies.…”

State-of-the-Art Diagnosis and Treatment of Hypertension in Pregnancy

“…91 Those requiring the vasodilatation also experienced more severe hypertension and had smaller babies. In 52 drug-naive pregnant women with various hypertensive disorders (38.5% chronic), when initial antihypertensive therapy was guided prospectively by hemodynamics, using initial nifedipine therapy when vascular resistance was high or women were of black race 92 and labetalol otherwise to achieve BP <140/ 90 mm Hg, the incidence of severe hypertension was low (3.8%) without compromising fetal growth. 93 Such a personalized approach based on hemodynamic assessment holds promise to optimize fetal growth for women receiving "tight" control of BP.…”

Serial hemodynamic monitoring to guide treatment of maternal hypertension leads to reduction in severe hypertension

“…We applied multilevel modeling because of the longitudinal assessment of the hemodynamic parameters with repeated measurements and because we sought to examine the potential effect of hypertension treatment on hemodynamic indices. The advantages of this methodology have been described previously.…”