Maternal Hemodynamics in Normal Pregnancies at 11–13 Weeks’ Gestation

Abstract

Objective: In women with established pre-eclampsia and gestational diabetes there is an increase in central aortic systolic blood pressure (SBP_Ao), pulse wave velocity (PWV) and augmentation index (AIx), which are measures of arterial stiffness. The aim of this study was to establish normal ranges for PWV, AIx and SBP_Ao at 11–13 weeks’ gestation and to examine the maternal characteristics which affect these parameters. Methods: This was a prospective study in singleton pregnancies at 11⁺⁰–13⁺⁶ weeks’ gestation. Maternal history and characteristics were recorded and PWV, AIx and SBP_Ao were measured. Multiple regression analysis was used to examine which of the maternal characteristics provided a significant contribution in the prediction of Alx-75, PWV and SBP_Ao. Results: In normal pregnancies PWV, AIx-75 and SBP_Ao were related to certain maternal characteristics, including increase with maternal age for AIx-75 and PWV, decrease with maternal height for AIx-75 and increase with maternal weight for PWV and SBP_Ao and decrease for AIx (p < 0.0001). The median, 5th, 10th, 90th and 95th percentiles for AIx-75 MoM (multiple of the unaffected median), PWV MoM and SBP_Ao MoM were 1.00, 0.72, 0.79, 1.34 and 1.48; 1.00, 0.77, 0.82, 1.24 and 1.33; and 1.00, 0.86, 0.88, 1.15 and 1.20, respectively. Conclusions: This study provides normal ranges for PWV, AIx and SBP_Ao at 11–13 weeks’ gestation and defines the maternal characteristics which affect these vascular parameters.