Pharmacokinetics of Oxytocin at Cesarean Delivery

PK measurements of oxytocin

The investigators will take serial readings from a digital durometer at the uterine fundus at 3, 6, 9 and 12 minutes following OXT administration to provide data that will inform an estimate of the timing of peak effect. Shore durometers measure the hardness of materials on a scale of 0-100 Shore Units (SU). Preliminary (unpublished) data provided a range of 10-56 SU after oxytocin administration at cesarean delivery. Durometer readings were also shown to correlate positively with the obstetrician's manual assessment of uterine contractility, which is traditionally used to determine the success or failure of uterotonic therapy.