Maternal hemodynamics in normal pregnancies at 11-13 weeks' gestation.

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.