Prediction of preeclampsia by evaluating the RI of placental second villi in the third trimester with HR-Flow ultrasound

To investigate the value of predicting preeclampsia (PE) using high resolution flow (HR-Flow) ultrasound to evaluate the resistance index (RI) of placental second villi in the third trimester. A total of 103 singleton pregnancies with follow-up results undergoing HR-Flow imaging of the placenta during the third trimester in the affiliated Yixing Hospital of Jiangsu University were recruited in this prospective cohort study from August 2021 to July 2023. Doppler resistance index values of the placental second villi were measured. Based on the clinical manifestations, the patients were divided into three groups: control (n = 78), hypertension (n = 11), and PE (n = 14). The performance of the second villous RI in predicting PE was analyzed using a receiver operating characteristic (ROC) curve. The PE group had a significantly higher rate of poor placental perfusion than the control and hypertension groups (P < 0.001, 0.048). The second villous RI values of the control, hypertension, and PE groups were 0.42 ± 0.10, 0.47 ± 0.07, 0.49 ± 0.06, respectively, with statistically significant differences among the three groups (P = 0.017). The area under the ROC curve for predicting PE was 0.734, the optimal cut off value was 0.50, and the sensitivity and specificity were 0.643 and 0.809, respectively. The optimal cut-off value of placental second villous RI may be a potential evaluation parameter for predicting PE, and is worthy of further study.