Up-Down Oxytocin Infusion

This study is designed to determine the minimum effective dose (ED90) of infusions of oxytocin for the prevention of uterine atony / postpartum hemorrhage and the need for additional uterotonics, in low risk parturients presenting for an elective CD. The primary outcome measure is the response of effective uterine contraction as either satisfactory or unsatisfactory as determined by the obstetrician blinded to the oxytocin infusion dose. Secondary outcomes will include need for additional uterotonics, calculated intra-operative blood loss and presence of oxytocin related adverse effects.