Impact of a third stage of labor oxytocin protocol on cesarean delivery outcomes

There are currently no standard recommendations regarding the dose, rate, or duration of intravenous oxytocin administration for the active management of the third stage of labor in the USA. In 2008, we initiated a standardized postpartum oxytocin protocol for active management of the third stage of labor. In cesarean deliveries, upon clamping of the umbilical cord, an oxytocin infusion of 18 U/h was started and adjusted upward if there was ongoing uterine atony. The aim of this study was to compare intraoperative data on oxytocin dose, estimated blood loss, supplemental uterotonic use and vasopressor use before and after the implementation of this protocol. We hypothesized that implementation of the protocol would result in lower intraoperative oxytocin doses without increasing estimated blood loss.

In this retrospective study, patient characteristics, estimated blood loss, vasopressor administration, and supplemental uterotonic use during two time periods were compared: the two-month interval before initiation of the oxytocin protocol and the two-month interval after initiation. Data were compared using the chi-squared test, t-test, or Mann-Whitney U test as appropriate. P < 0.05 was considered significant.

Data for 901 deliveries were analyzed. The amount of intraoperative oxytocin administered decreased after implementation of the protocol (median difference 8.4 U, 95% CI 7.4 to 9.4). Although there was an increase in estimated blood loss, there were no differences in the percentage of patients experiencing intraoperative blood loss >1000 mL or the need for additional uterotonic mediations between the two time periods.

We found that the use of an oxytocin management protocol reduced the amount of intraoperative oxytocin administered without increasing the rate of postpartum hemorrhage or the need for additional uterotonics. Clinicians may consider using a rate of 18 U/h as a starting point for administration of oxytocin to achieve adequate uterine tone in healthy parturients for prevention of postpartum hemorrhage.