Antenatal diagnosis of placenta percreta using gray‐scale ultrasonography, color and pulsed Doppler imaging

We report the findings of a 34-year-old patient with a past history of a straightforward postoperative course following a transverse cesarean section for delivery of her first child. During her second pregnancy an anterior placenta previa covering the internal cervical os was identified. No metrorrhagia was reported. The first ultrasound examination, performed at 30 weeks in our department, revealed focal signs of placenta percreta in the region of the lower bladder wall. There was a longitudinal absence, extending for 7.7 cm, of the hypoechoic or anechoic retroplacental zone. Focal disruption of both the uterine serosa and the hyperechoic bladder wall with intraplacental lacunae was also evident (Figure 1). Color Doppler imaging identified vessels crossing from the placenta into the bladder wall. Pulsed Doppler revealed that these vessels were arteries with a diastolic flow (Figure 2), which were inferior to the spiral arteries. The intraplacental lacunae were vascular with either venous or arterial flow. The patient was informed of the diagnosis and the therapeutic consequences. A Cesarean section was scheduled. Anesthetic and gynecological teams were doubled and the presence of a urologist was arranged. Provision was made for a possible massive blood transfusion. A preoperative cystoscopy showed abnormal vessels in the region of the lower bladder wall. A Cesarean hysterectomy was performed. Placenta previa percreta extending to and covering the internal cervical os. Intraplacental lacunae can be identified together with a loss of the hypoechoic retroplacental myometrial zone. Pulsed Doppler evaluation of the vessels revealing flow to be arterial which is inferior to the spiral arteries. The macroscopic examination of the uterus revealed a focal invasion of the placental villi throughout the myometrium extending to the uterine serosa. This was the fourth case of abnormal adherence of the placenta that we have diagnosed antenatally. In view of the serious maternal prognosis in this condition the ability to reach a correct diagnosis antenatally is of great importance. From our experience we believe that placenta accreta/increta can be successfully identified prenatally and that this is best achieved by the complementary combination of grey-scale sonography, colour and pulsed Doppler.