Placenta percreta and the urologist.

Placenta percreta, the rarest and most severe form of placenta accreta, can involve the urinary bladder. Because of its propensity for severe hemorrhage, it is a potentially life-threatening condition. Although commonly discovered at the time of delivery, antenatal diagnosis may be achieved with ultrasound, magnetic resonance imaging, and/or cystoscopy. Every attempt should be made to minimize potential for blood loss by avoiding removal of the placenta at the time of delivery and either performing a hysterectomy or using methotrexate therapy to ablate the residual placenta in the postpartum period. If hemorrhage does occur during delivery, immediate surgical removal of the uterus should be considered and, depending on the severity of the hemorrhage and the depth of invasion of the placenta into the bladder, excision and/or reconstruction of the bladder may be necessary.