Active management of the third stage of labor: Does the application mode of oxytocin influence the outcome?

Introduction: Postpartum haemorrhage is the leading cause of maternal mortality worldwide. Prophylactic administration of uterotonics, such as Oxytocin, during the third stage of labor is a well established intervention to significantly decrease the incidence of PPH. In order to decrease haemodynamic and cardiovascular adverse effects the administarion of Oxytocin as an intravenous bolus (5 IE) has been replaced by an intravenous short-term infusion (5 IE Oxytocin i.v. over a period of 5 minutes) in Switzerland in 2010. The aim of this study was to compare the incidence of postpartum adverse outcome after this adjustment in therapy.

Material and methods: A monocentric retrospective cohort study was carried out in the Cantonal Hospital in St. Gallen comparing outcomes of the third stage of labor before and after the change of the Oxytocin application mode. Two groups were classified: a bolus group (2005 – 2009, n = 2486) and an infusion group (2011 – 2015, n = 2391). The study included only low-risk births of spontaneous delivered live singletons from 37 weeks of gestation without induction or previous cesarean section.

Results: We found significant differences between the two groups with an increase in estimated blood loss (OR 2.42, p < 0.000), in incomplete detachment of placenta (OR 0.77, p 0.019), in manual removal of retained placenta (OR 1.8, p 0.002) and in postpartum curettage (OR 3.1, p < 0.000) in the infusion group.

Conclusion: The intravenous short-term infusion of Oxytocin is less effective than the bolus application in terms of successful management of third stage of labor.