[Placenta accreta: Frequency, prenatal diagnosis and management].
In the last 30 years, incidence of placenta accreta has dramatically increased to reach an alarming rate of more than one in 2500 deliveries. The rate of placenta accreta increased in conjunction with cesarean deliveries. 2D-ultrasonography is an useful tool to diagnose placenta accreta. The most reliable sign is the presence of abnormal placental lacunae. The lack of visualization of the echolucent area between the placenta and the myometrium with no other ultrasound finding has a poor sensitivity and positive predictive value. 3D power Doppler is useful to increase the diagnostic performance of 2D-ultrasonography. The presence of at least two ultrasound findings decreases the number of false-positive diagnosis and increases the performance of both 2D-ultrasonography and 3D power Doppler. Magnetic resonance imaging in cases with inconclusive ultrasound features optimizes diagnostic accuracy. In cases of prenatal diagnosis of placenta accreta, extirpative method should be to date abandoned. Advantages and disadvantages of both cesarean-hysterectomy and conservative treatment should be clearly explained to the patient and her partner, who have to be involved in the decision process. Currently, it seems to be reasonable to propose a cesarean-hysterectomy to multiparous patients with no desire of future pregnancy. In young women who want the option of future pregnancy and who agree to close follow-up monitoring, conservative treatment should be preferred. When placenta accreta is diagnosed during the delivery, the two options remain possible only if attempts of removal of the placenta are stopped before the occurrence of a severe postpartum hemorrhage. In cases of placenta percreta with bladder involvement, conservative treatment may be the optimal management.