Endothelial cell function enhancement in a late normal human pregnancy

Objective: To assess endothelial cell function throughout normal human pregnancy. Design: Longitudinal observational study. Population: Pregnant women attending antenatal clinics and female nursing staff. Methods: Flow mediated dilatation (FMD) was measured by high resolution ultrasound and used as a surrogate measure for endothelial cell function and measured in pregnant women and in non-pregnant female controls. Measurements were performed throughout normal pregnancies in each trimester. Results: Mean FMD was increased by 80% and 64% in the third trimester compared to the first and second trimesters, respectively, and by 92% compared to the mean FMD of the non-pregnant controls. The increased FMD in the third trimester was demonstrated to be statistically significant in comparison with all the above groups by two-sample t-tests (P < 0.01 for all comparisons). Conclusion: Endothelial cell function, measured by ultrasound assessment of FMD, is enhanced in late normal human pregnancy.