Role of Shear Wave Elastography of Placenta in Prediction of Preeclampsia in High-Risk Pregnancy.

Abstract

The aim of our study was to compare the placental elasticity values between normal pregnancies and preeclamptic pregnancies and evaluate the utility of shear-wave elastography of the placenta as a predictor for preeclampsia in high-risk pregnancy. A prospective study was performed with 90 singleton high-risk pregnancies having any of the 7 risk factors for developing preeclampsia (primigravida, history of preeclampsia, family history of preeclampsia, history of pregestational diabetes, chronic hypertension, advanced maternal age [≥40 years], and body mass index ≥26 kg/m 2 ) were enrolled in the study. Shear-wave elastography was performed in all patients at 20 to 24 weeks' gestation and at 34 to 36 weeks' gestation, at 2 sites: center and edge of the placenta. The patients were divided into 2 groups: normal pregnancies (group A) or developed preeclampsia (group B). Women with posterior placentation, obstetric disorders other than preeclampsia, or multiple gestation were excluded from the study. Group comparisons were done using the χ2 test or Fisher exact test. Shear-wave elasticity values at 20 to 24 weeks' gestation for group B at the center of the placenta (21.73 vs 9.72 kPa) and at the edge of the placenta (21.6 kPa vs 10.15 kPa) were significantly higher than those for group A ( P < 0.05). Similar results were seen at 34 to 36 weeks' gestation. With a cutoff of 13.1 kPa, we attained sensitivity of 95.2%, specificity of 92.8% and diagnostic accuracy of 93.3% for predicting development of preeclampsia. Patients with preeclampsia have a significantly higher stiffness of the placenta. Shear-wave elastography is useful to evaluate placental function. Elastography can be used as a supplementary tool for prediction of preeclampsia.