Background: Pre-eclampsia is a major hypertensive disorder of pregnancy occurring after twenty weeks of gestation and is associated with hypertension, proteinuria, endothelial dysfunction, and altered placental perfusion. These pathological changes can modify placental stiffness. Acoustic Radiation Force Impulse Elastosonography is a non-invasive ultrasound technique that quantifies tissue elasticity by measuring shear wave velocity. Assessing placental elasticity may aid in identifying pre-eclampsia earlier and more accurately.
Objectives
1. To compare placental shear wave velocities in pre-eclamptic and healthy pregnant women.
2. To determine a shear wave velocity cut-off value indicative of pre-eclampsia.
Methodology: The study included thirty-five healthy pregnant women and thirty-five women with pre-eclampsia who met the inclusion criteria and provided informed consent. Placental stiffness was measured using Acoustic Radiation Force Impulse Elastosonography. Shear wave velocity values were obtained from three placental regions—foetal surface, maternal surface, and central portion—with three readings from each region, totalling nine measurements per participant. Mean and median shear wave velocities were calculated for comparison and diagnostic evaluation.
Results: The mean placental shear wave velocity was 2.055 m/s in pre-eclamptic women and 1.14 m/s in healthy pregnant women. Receiver operating characteristic analysis demonstrated an area under the curve of 0.995. A shear wave velocity cut-off of 1.535 m/s yielded a sensitivity of 97% and a specificity of 96% for identifying pre-eclampsia.
Conclusion: Placental stiffness assessment using Acoustic Radiation Force Impulse Elastosonography after twenty weeks of gestation is a reliable, non-invasive method for detecting pre-eclampsia. Higher shear wave velocities were consistently observed in pre-eclamptic placentas, with a cut-off of 1.535 m/s showing excellent diagnostic accuracy. This technique may serve as a valuable adjunct in evaluating placental function and identifying pre-eclampsia.
International Journal of Radiology and Diagnostic Imaging
