60 pregnant women with singleton living healthy fetus diagnosed as having placenta previa by grey scale ultrasound and candidate for repeated elective cesarean section (CS) or elective cesarean hysterectomy (if the diagnosis of placenta accreta is confirmed) will be included in the study. Inclusion criteria include: maternal age between 20 \& 40 years old, gestational age more than 28 weeks (confirmed by a reliable date for the last menstrual period and 1st trimester ultrasound scan), one or more cesarean section scar \& the presence of placenta previa with high possibility of being placenta accreta when scanned by grey scale ultrasound. Women who had chronic or pregnancy induced diseases or any emergency or unplanned CS will be excluded. Informed consents will be obtained from all patients after explanation of the aim of the study \& the potential risks. For all patients, full history will be taken followed by complete physical examination \& routine obstetric ultrasound (to confirm the presence of placenta previa i.e. placental tissue covers the internal cervical os or within 2 cm from it). For all Participants, the placentae will be reexamined in systematic manner by gray-scale \& color Doppler ultrasound via transabdominal and/or transvaginal approach using Volusion Pro-V ultrasonography machine (GE Healthcare Austria GmbH, Seoul, Korea). All exams will be done by expert sonographer \& the possibility of concomitant placenta accreta will be checked. The placenta will be scanned with adequate bladder volume to visualize the bladder- uterine serosal interface correctly \& the angle of insonation will kept as low as possible. The presence of one or more of the following features in grey scale ultrasound will be indicative of placenta accreta (presence of abnormal placental lacunae / complete loss of retroplacental sonolucent zone / myometrial thinning / disruption of the uterine serosa-bladder interface / presence of mass invading the urinary bladder). Similarly, placenta accreta will be diagnosed by the presence of at least one of the following features in color Doppler scan: diffuse or focal lacunar flow - sonolucent vascular lakes - hypervascularity of the utero-vesical interface with bridging vessels connecting the placenta to the bladder). The sonographic provisional diagnosis (i.e placenta previa, focal accreta, accreta , increta or percreta) with the concomitant invasion of adjacent structures (e.g., the urinary bladder) will be documented. For all participants, termination of pregnancy will be by elective CS or elective cesarean hysterectomy. Furthermore, operative findings as regard the placenta and the invasion of adjacent structures will be documented. All operative procedures will be done by senior staff obstetrician with special interest in placenta accreta. For hysterectomy specimens, histopathological examination will be done to assess the degree of myometrial invasion \& to confirm the diagnosis of placenta accreta. Maternal morbidities (i.e. massive bleeding with the need of blood transfusion, pelvic organ injury or ICU admission) or mortalities will be documented. Neonatal morbidities (i.e. prematurity or NICU admission) or mortalities will be documented. The ultrasonographic findings will be compared to operative details and histopathological reports. The aim of the study is to evaluate the efficacy of ultrasound in predicting operative findings and associated co-morbidities among cases of placenta accreta.