995: Maternal central blood pressure is associated with middle cerebral artery dopplers

Abstract

Our objective was to create maternal cardiac profiles of pregnant women using non-invasive measurements of central BP to identify changes in maternal hemodynamics and the effect on the fetus. This was a prospective cohort study of all pregnancies followed in a single perinatal referral center. Antenatal data was collected for analysis. Central BP was measured non-invasively using the Uscom BP+ device, a supra-systolic oscillometric central BP (cBP) device, which measures BP waveforms peripherally in the arm. The BP+ device calculates central BP and pulse pressure waves using a physics-based model of the arteries between the aorta and the cuff. The Student’s t-test was used to compare categorical means and Spearman rank correlation was used to evaluate correlations between continuous variables. 279 women were recruited for the study. The Uscom BP+ device information was categorized by patient and gestational age (GA) based on ultrasound at the time of the visit. Mean maternal age was 32.4 years (19-54). For first trimester (n=121), the mean central systolic BP was 103.1 mmHg (standard deviation 12.4), the mean central diastolic BP was 67.3 mmHg (10.1), and the mean pulse was 81 bpm (11). For second trimester (n=132), the mean central systolic BP was 100.5 mmHg (12.0), the mean central diastolic BP was 66.7 mmHg (10.8), and the mean pulse was 83 bpm (13). For third trimester (n=39), the mean central systolic BP was 105.8 mmHg (13.1), the mean central diastolic BP was 72.8 mmHg (11.7), and the mean pulse was 91 bpm (9). Both central systolic and diastolic BP were correlated to peripheral systolic and diastolic BP (p<0.01). Central BP was not found to be directly correlated to the estimated fetal weight (EFW) (n=167) (p>0.42). Central BP was negatively correlated to the pulsatility index (PI) for the middle cerebral artery (MCA) (n=19) (p<0.05). Additionally, the MCA PI was found to be positively correlated to the EFW (p<0.05). Non-invasive measurement of maternal central BP likely provides a more accurate indicator of utero- placental perfusion pressure and downstream vascular resistance. We demonstrate that maternal central BP correlates to the MCA PI and, vis-à-vis, EFW.