Shear-wave elastography for detection of placenta percreta: a case-controlled study

Prenatal diagnosis of placenta percreta (PP) is important to be able to provide effective management and a multidisciplinary approach to minimize the complications.

To evaluate the role of shear-wave elastography (SWE) in the prenatal diagnosis of PP.

A total of 18 women with PP and 20 pregnant women with normal placenta in the second or third trimesters were included in this prospective study. SWE was used to determine the elasticities of the placenta (in the maternal edge of the placenta) and myometrium. The obstetric data regarding grayscale and Doppler ultrasonography, and perinatal outcomes were reviewed. A mean placental SW velocity (SWV) cut-off value was determined to predict the presence of placental adherence.

The SWV values of the PP group in the maternal edge of the placenta were significantly higher than those of the control group (1.95 ± 0.19 m/s and 1.69 ± 0.23 m/s; P = 0.001). Myometrial SWV was also higher in the PP group compared to the control group (2.25 ± 0.39 m/s and 1.90 ± 0.71 m/s; P = 0.002). A receiver operating characteristic (ROC) curve analysis was performed and the best cut-off value of placental SWV was determined as 1.92 m/s with sensitivity of 58% and specificity of 80%, to predict the placental adherence in patients with PP.

Placental stiffness was significantly higher in patients with PP than in pregnant women with normally localized placenta. Thus, we thought that SWE of the placenta might be used as an alternative method in the diagnosis of PP.