Role of Ultrasonography in Placenta Accreta Spectrum

Placenta Accreta Spectrum (PAS) describes the clinical situation when after delivery of the fetus the placenta does not detach normally from the uterus and cannot be removed without causing potentially catastrophic maternal hemorrhage. The incidence of PAS has increased worldwide, most likely associated with the rising rates of cesarean delivery. PAS is the most common reason for peripartum hysterectomy and contributes to the current failure to reduce the maternal death rate in high-income countries. Antenatal recognition of PAS is important to initiate multidisciplinary planning for a safe delivery in a center of expertise to reduce maternal mortality and morbidity. In this chapter, medical and technical aspects of placental (Doppler) ultrasound are described and related to clinical management. To illustrate the abnormal findings, the ultrasound images and perioperative findings of two patients are visualized.