Evaluation of a Healthy Pregnant Placenta with Shear Wave Elastography

Background: The placenta is a soft organ with vital importance. Increased placental stiffness was reported in pathological conditions emerging during pregnancy, such as diabetes mellitus and hypertension. Nowadays, placental stiffness can be quantitatively measured using the shear wave elastography (SWE) technique. Objectives: We aimed to assess the factors affecting elasticity by finding the normal elastogram values of healthy pregnancy placentas using the SWE technique due to the importance of early diagnosis in risky pregnancies. Patients and Methods: In total, 288 healthy pregnant women in the second or third trimester were included in our prospective study. The pregnant women who had pathology in their fetus and its appendices or a posteriorly located placenta were excluded from the study. Obstetric ultrasonography and a placental elasticity assessment were performed in all the pregnant women. Speed values were obtained from five different locations of the placenta, including the central S1, S2, S3, S4 and peripheral P regions. The elasticity of the regions were compared, and the factors affecting elasticity were investigated. Results: There were significant differences among the velocity values obtained from five different areas of the placenta. The mean velocity values obtained from the central region were higher than those of the peripheral region (P < 0.001). There was also a significant difference in the mean velocity measurements obtained from the central region (P < 0.001). The hardest region of the placenta was the maternal surface, while the softest region was the peripheral surface. The elastographic velocity values of the placenta were found to correlate with maternal age, body mass index, placental localization, thickness, and grade, whereas it did not correlate with gravidity, parity, gestational week, and amniotic fluid index . Conclusion: The elasticity of the placenta varied according to the region and surface, whereas it did not change according to gestational week. It may be convenient to use the elasticity values obtained by SWE from specified regions in the follow-up of placentas in high-risk pregnancies. However, considering the affecting factors and contradictory study results, a large number of large-scale studies is required to strengthen the efficiency of SWE in the placental assessment.