Characterization of placenta accreta using transvaginal sonography and color Doppler imaging.

The safe use of transvaginal sonography in patients with placenta previa has been confirmed, and has revolutionized precise placental localization. The aim of our study was to evaluate the efficacy of transvaginal sonography and color-coded blood flow in the prediction of placenta accreta. Twenty-one patients with persistent placenta previa were scanned using transvaginal sonography and color-coded flow. Suspicion for placenta accreta consisted of total placenta previa at term with several placental lacunae exhibiting marked or turbulent blood flow, as seen with color Doppler transvaginal sonography from within the placenta, extending into the surrounding tissues. Five of the patients exhibited sonographic placental patterns suspicious for placenta accreta and one patient exhibited placental and cervical blood flow described as lacunar. Five Cesarean hysterectomies were performed for placenta accreta. Every placenta accreta was correctly diagnosed sonographically by the use of color flow studies. One patient with suspicion of placenta accreta delivered at another institution, a Cesarean hysterectomy was performed, and the pathology was confirmed. The one placenta previa exhibiting turbulent lacunar flow in the cervical area only was not confirmed to be an accreta at Cesarean section, although hemostasis was difficult at the placental bed. The remaining 15 patients with placenta previa and who on sonography were not suspicious for placenta accreta underwent uncomplicated Cesarean section. Transvaginal sonography and color Doppler imaging improve the diagnostic accuracy in the prediction of placenta accreta in patients with persistent placenta previa. A pattern of turbulent blood flow extending from the placenta into the surrounding tissues should alert the physician to the possibility of placenta accreta.