title: Maternal ethnicity and its impact on the haemodynamic and blood pressure response to labetalol for the treatment of antenatal hypertension.
abstract: Blood 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.
  
  
  
  This 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.
  
  
  
  Both 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.
  
  
  
  There 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.
authors.affiliation: Division of Women's Health , Antenatal Hypertension Clinic, King's College Hospital , London , UK.
authors.forename: D
authors.initials: D
authors.lastname: Stott
authors.affiliation: Division of Women's Health , Antenatal Hypertension Clinic, King's College Hospital , London , UK.
authors.forename: M
authors.initials: M
authors.lastname: Bolten
authors.affiliation: Division of Women's Health , Antenatal Hypertension Clinic, King's College Hospital , London , UK.
authors.forename: D
authors.initials: D
authors.lastname: Paraschiv
authors.affiliation: Leto Maternity Unit, Athens , Greece.
authors.forename: I
authors.initials: I
authors.lastname: Papastefanou
authors.affiliation: Cardiothoracic Centre, Guy's and St Thomas Hospital , London , UK.
authors.forename: J B
authors.initials: JB
authors.lastname: Chambers
authors.affiliation: Division of Women's Health, Antenatal Hypertension Clinic, King's College Hospital, London, UK; Division of Women's Health, Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: N A
authors.initials: NA
authors.lastname: Kametas