Abnormal placentation.

The term "morbidly adherent placenta" has recently been introduced to describe the spectrum of disorders including placenta accreta, increta and percreta. Due to excessive invasion of the placenta into the uterus there is associated significant maternal morbidity and mortality. Most significant risk factors for morbidly adherent placenta include history of prior cesarean delivery as well as placenta previa in the current pregnancy. Ultrasound remains the gold standard for antenatal diagnosis, however, in recent years MRI has assisted in identifying complex parametrial involvement. Optimizing maternal and neonatal outcomes involves early prenatal diagnosis, a multi-disciplinary team-based approach, and referral to an experienced center.