OBJECTIVE: To compare maternal central hemodynamics between White, Black and Asian women.
METHODS: This was a prospective, longitudinal study of maternal central hemodynamics by a bioreactance method at 11+0 -13+6 , 19+0 -24+0 , 30+0 -34+0 and 35+0 -37+0 weeks' gestation, in White (n=1165), Black (n=247) and Asian (n=116) women. Multilevel linear mixed-effects analysis was performed to compare the repeated measures of the cardiac variables controlling for maternal characteristics and medical history.
RESULTS: Cardiac output (CO) increased with gestational age to a peak at 32 weeks; the highest CO was in White women and the lowest in Asian women. Stroke volume (SV) increased with gestation in White women, decreased in Black women and remained static in Asian women. Heart rate (HR) increased with gestation to 32 weeks and then remained constant; HR was highest in Black women and lowest in White women. Peripheral vascular resistance (PVR) showed a reversed pattern to CO; the highest values were in Asian women and the lowest in White women. The least favourable hemodynamic profile in Black and Asian, compared to White women was reflected in the higher rates of small for gestational age infants.
CONCLUSION: There are race-specific differences in maternal cardiac adaptation in pregnancy. White women have the most favourable cardiac adaptation by increasing SV and HR, achieving the highest CO and lowest PVR. In contrast, Black and Asian, compared to White women, have lower CO and higher PVR, increasing their CO through a rise in HR due to a declining or static SV. This article is protected by copyright. All rights reserved.