Objectives: To clarify whether ultrasonographic evaluations of fetoplacental underperfusion using umbilical artery (UmA) Doppler indices at 36 weeks' gestation can predict maternal hypertension at later gestation.
Methods: Normotensive pregnant women who underwent an ultrasound scan at 36 weeks' gestation and delivered singleton infants at term between 2012 and 2013 were prospectively enrolled. UmA Doppler and maternal blood pressure results at 36 weeks' gestation in cases with pregnancy-induced hypertension (PIH) at later gestation were compared with a control group.
Results: Thirty-nine and 775 cases were classified into the PIH and control group, respectively. The UmA pulsatility index (PI) and maternal systolic blood pressure (SBP) at 36 weeks' gestation were higher in the PIH group than in control group (UmA-PI: 0.88 vs. 0.80, p = 0.002; SBP: 126 mmHg vs. 112 mmHg, p < 0.001). The area under the ROC curve for the prediction of PIH by combining the UmA-PI and SBP was 0.867 (95% confidence interval (CI): 0.781, 0.954). The detection rate for PIH was 64.0% with a 10% false-positive rate.
Conclusions: An increased UmA-PI at 36 weeks' gestation is associated with the occurrence of PIH at later gestation. This result may indicate the possibility to detect fetoplacental underperfusion ultrasonically.
Keywords: Maternal blood pressure; preeclampsia; pregnancy-induced hypertension; umbilical artery pulsatility index.