MATERNAL CARDIOVASCULAR EFFECTS OF PLACENTAL DYSFUNCTION IN THE 2ND TRIMESTER

Abstract

Preeclampsia occurs in 3% of pregnancies. Women who develop severe/early-onset PE (sPE) demonstrate extensive cardiovascular abnormalities. The purpose of this study was to compare baseline measures of cardiovascular function in pregnant women at high-risk of developing sPE to those observed in healthy pregnant controls in the 2nd trimester. Pregnant women at high-risk of sPE (n=24) and healthy pregnant controls (n=20) are recruited to undergo baseline assessment at 22-26 weeks of gestation. Cardiovascular function is assessed by heart rate (HR), blood pressure (BP), non-invasive cardiac output (CO) measurement (NICOM), flow-mediated dilation (FMD), and uterine artery Doppler. Urine and bood samples are also collected. 23 high-risk women and 13 controls have participated in the study to date. There were no significant differences in maternal age (32±4 vs 34±3; p=0.12), maternal BMI (28.4±4 kg/m2 vs 25.7±5 kg/m2; p=0.06) or gestational age at the time of the study (24±2 weeks vs 24±1 weeks; p=0.44) between the high-risk group and controls. Gestational age at delivery was significantly earlier in the high-risk group when compared to controls (34±3 weeks vs 39±2 weeks; p<0.001), with 57% of the high-risk women developing sPE vs 0% of the healthy controls to date. At baseline, HR was higher in the high-risk group as compared to controls (84±12 bpm vs 75±6 bpm; p=0.03). Systolic and diastolic BP were also higher in the high-risk group (118±11 mmHg vs 108±11 mmHg; p=0.03, 69±10 mmHg vs 62±4 mmHg; p=0.04). Systolic blood pressure correlated positively with serum uric acid levels (p=0.02). Despite their higher HR, CO was significantly lower in the high-risk group as compared to controls (5.9±0.9 L/min vs 7.6±1 L/min; p<0.001). Systemic vascular resistance was also higher in the high-risk group (1189±248 dyn·s·cmˆ5 vs 872±135 dyn·s·cmˆ5; p<0.001). There was no significant difference in FMD between high-risk and control groups (6.4±4% vs 8.8±5%; p=0.19). Uterine artery Doppler-based pulsatility index was significantly higher in the high-risk group at baseline (1.8±0.5 vs 0.88±0.1; p<0.001), and correlated positively with systemic vascular resistance (p<0.001). Women at high-risk of developing sPE exhibit abnormalities in baseline cardiovascular function.