Objective: We aimed to assess the predictive values of individual sonographic findings of abnormal placentation to determine the candidates for segmental resectionStudy design: This was a retrospective review of 43 pregnancies with at least one prior cesarean delivery who received an ultrasound diagnosis of placenta previa or low-lying placenta with suspected abnormal placentation in the third trimester at our institution from 2015 through 2017. Sonographic images were reviewed by an investigator blinded to pregnancy outcome. Sonographic parameters were assessed including loss of retroplacental clear zone, irregularity and width of uterine-bladder interface, smallest myometrial thickness, presence of lacunar spaces, and bridging vessels. Diagnosis of placental invasion was based on histologic confirmation. Parameters were analyzed to predict candidates for conservative approach.Results: There were 27 cases with cesarean hysterectomy where as conservative approach was successful in 16 of the cases. Numbers of transfusions of packed red blood cells (2.6 vs. 1.7), fresh frozen plasma (2.3 vs. 0.9) and mean smallest retroplacental myometrial thickness (1.3 vs. 2.1 mm) were significantly different between the two groups (p < .05). Smallest retroplacental myometrial thickness was a significant predictor for the cases appropriate for successful conservative approach (Area Under Curve, AUC =0.911, p < .001), optimal cut off value was obtained at 1.6 mm with 94% sensitivity and 85% specificity.Conclusions: Our data showed that among some sonographic findings of abnormal placentation, smallest myometrial thickness was a significant predictor to determine candidates for conservative approach.
Keywords: Accreta; invasion; myometrial thickness; retroplacental; ultrasound.