Morbidly adherent placenta

There are three grades of morbidly adherent placenta: accreta, increta and percreta. They are defined according to the depth of myometrial invasion.

  • accreta: chorionic villi are in contact with the myometrium (middle layer of the uterine wall) rather than being contained within the decidua (inner lining of the uterine wall during pregnancy) (approximately 80% of cases)
  • increta: extensive villous invasion into the myometrium (approximately 15% of cases)
  • percreta: villous invasion extends to (or through) the serosa (membrane covering the uterus) (approximately 5% of cases).