The investigators evaluated the efficacy of a staging system introduced by the American Institute of ultrasound in medicine 2015 including sonographic parameters associated with morbidly adherent placenta for antenatal prediction of placental invasion.

Morbidly adherent placenta (MAP) defines a spectrum of conditions, including placenta accreta, increta, and percreta, which are associated with significant maternal and fetal morbidity and mortality. Ultrasound evaluation, with grayscale, is the recommended first-line modality for diagnosing MAP. Grayscale ultrasound features suggestive of placenta accreta include the loss of myometrial interface or retroplacental clear space, reduced myometrial thickness and the presence of intraplacental lacunae. Using a staging system by antenatal ultrasound can predict placental invasion antenatally.

Inclusion Criteria:

• Prior lower segment cesarean section
• Low lying anterior placenta
• Singleton pregnancy

Exclusion Criteria:

• Medical disorders
• vasa previa