Parturients aged 18-50 with an intrauterine term pregnancy (37 weeks or greater) undergoing non-emergent cesarean delivery at the University of Chicago (UC) and Stanford University will be recruited.
Methods: All subjects will receive standard pre-, intra- and postoperative care for their cesarean delivery with additional study interventions.
Study subjects will have an additional intravenous (IV) catheter inserted for intra-operative study-related blood draws.
A single, 1 International Unit (IU) bolus of deuterated oxytocin (d5OT) will be given to the subject, followed by an infusion of standard protocol oxytocin immediately after placental delivery. IV samples will be drawn from the study IV at 0, 1, 2.5, 5, 10, 20, 30, 45, 60 minutes following administration of the study drug. The samples will be processed, batched and shipped to the central lab being used in this study. Uterine tone scores will be measured simultaneously with blood draws until accurate palpation is no longer possible. Uterine tone score is a 0 to 10 numeric rating scale with 0 to describe unsatisfactory or no uterine tone and 10 to describe perfect uterine tone.