Womenwith placenta previa after 32 weeks will be assessed for participation if they are eligible an adequate data will be taken :~- Clinical factors : including maternal age, abortion history, cesarean section history, gestational age at delivery, whether the operation will be carried out as an emergency surgery, and whether bleeding has started before the operation, will evaluated. The number of abortion history will be counted only if a dilatation and curettage was performed. Preoperative hemoglobin and hematocrit values will be checked. The amount of PRBCs transfused during operation will be measured.~-Ultrasonographic factor: Adiagnosis of placenta previa was made when the placenta covered the internal orifice of the cervix after 32 weeks' gestation. We will check for the presence of a hypoechoic area between the myometrium and the placenta. The vascularity of the placenta will be classified as normal or hypervascular on color Doppler imaging. We will examine the location of placenta ( anterior . posterior. Anterior with lateral deviation. Posterior with lateral deviation) and presence ofintraplacental lacunae (an irregular area of low echogenicity larger than 1 cm × 1 cm in the placental parenchyma)~Intraoperative factor:~Assess surgeon years of experience Management plan hemostatic sutures other conservative management hysterectomy (primary or secondary) Assessment of amount of blood taken in 24 h from operation
To assess the ability of clinical and sonographic variables to predict the need of blood transfusion > 4 units of packed RBCS in women undergoing cesarian section for placenta previa .