Decreases in mean blood pressure greater than 20% from baseline or less than 90 mm Hg will be defined as hypotension and will be treated with incremental doses of phenylephrine (50-100mcg IV) or ephedrine (5mg) if maternal heart rate is less than 60 bpm. A 500cc lactated ringers bolus will be co-administered with initiation of the spinal anesthetic. Further fluids will be administered with a goal of approximately 1-1.5 liters intraoperatively. Each patient will in addition receive 20 units Oxytocin in 500cc saline. Additional fluid or uterotonics will be given as necessary for bleeding or hypotension and will be taken into account at the end.