High Versus Low Dose of Magnesium Sulfate as Initial Tocolytic Agent for Preterm Labour in Symptomatic Placenta Previa.

"Patients will be assessed hourly for pulse and blood pressure, contraction frequency, vaginal bleeding. With strict monitoring for symptoms of magnesium sulfate toxicity.~All patients will receive dexamethasone to enhance fetal lung maturity. Rhesus factor status will be determined for all patients, . Hb level will be measured and anemic patients will receive correction by blood transfusion Cervical length will be measured after 24 h\& 48 h from administration of magnesium sulfate in both groups Maternal serum magnesium will be measured at admission and after 4 hours ,12 hours and 24 hours after administration of magnesium sulfate Patients of both groups will be assessed for their neonatal outcomes include deaths and gestational age at delivery, fetal birth weight. Apgar score at five minutes, neonatal intensive care unit admission and duration of admission and neonatal calcium level at time of delivery will be also assessed."