O113. Measurements of arterial stiffness and uterine artery Doppler for the prediction of preeclampsia in women presenting with gestational hypertension

Abstract

Objective While gestational hypertension (GH) and chronic hypertension are usually benign, pre-eclampsia (PE) is more commonly associated with adverse maternal and fetal outcomes. About 15–25% of women initially diagnosed with GH will develop PE, but only 10% of women who develop GH after 36 weeks of gestation will develop PE. Pulse wave velocity (PWV) and augmentation index (AIx) are markers of arterial stiffness and endothelial dysfunction, while uterine artery Doppler pulsatility index (UtA PI) reflects the resistance in the uteroplacental circulation. These parameters have been shown to be associated with the risk of PE. The main aim of this study was to investigate whether maternal cardiovascular changes can discriminate pregnancies which will subsequently develop PE among those presenting with GH. Methods This was a prospective cohort study in women with singleton pregnancies presenting with GH at St George’s Hospital (n = 112). Another group of uncomplicated singleton pregnancies were recruited as controls. PWV, AIx and aortic systolic blood pressure (SBPAo) were recorded using the Arteriograph® (TensionMed Ltd., Budapest, Hungary). The uterine artery Doppler was recorded on both sides and the mean PI was calculated. Mann-Whitney and Chi-Square tests were used to compare the groups, while regression analysis was used to identify and adjust for potential confounders. The predictive accuracy for the development of PE was assessed using the ROC curve analysis. Results The analysis included 105 pregnancies with GH and 356 controls. Compared to the group that remained as GH (n = 82), the group that developed PE (n = 23) had significantly higher AIx (25.9%, IQR 12.8–34.3 vs 15.8%, IQR 6.1–25.6; p = 0.019) and SBPAo (141 mmHg, IQR 130–158 vs 130 mmHg, IQR 123–142; p = 0.005) at the initial assessment. They also had significantly higher UtA mean PI at 20–24 weeks (1.10, IQR 0.78–1.47 vs 0.83, IQR 0.68–1.04; p = 0.008). AIx was significantly associated with the risk of development of PE (odds ratio 1.05; 95% CI 1.01–1.09, p = 0.016). For a cut-off of 31.18%, AIx had sensitivity of 41.2% (95% CI 18.4–67.1%) and specificity of 93.2% (95% CI 83.5–98.1%) and LR 6.07 (AUC 0.69; 95% CI 0.53–0.84, p = 0.019). Conclusion Arterial stiffness and SBPAo measured at the initial assessment of GH can potentially discriminate the pregnancies that will develop PE. Identification of women who will develop PE among those who initially present with PIH is likely to facilitate targeted antenatal surveillance and possibly intervention.