Cesarean Section Rate in Oxytocin Infusion between Continuous Until Delivery and Discontinuation at Active Phase of Labor: a Randomized Controlled Study

Objective: To compare the cesarean section rate between discontinuing oxytocin infusion for labor induction or augmentation when the active phase of labor is established and continuing oxytocin infusion until delivery. Materials and methods: This was a prospective randomized controlled trial of 340 pregnant women who underwent labor induction or augmentation at Bhumibol Adulyadej Hospital during February 2014 to January 2015. Parturient were randomly and equally allocated into two groups. The continued group received oxytocin infusion throughout all stages of labor. The discontinued group received oxytocin infusion and early discontinued when the active phase of labor had begun. Intention to treat analysis was used in this study. Results: Three hundred and forty pregnant women were enrolled for the study. They were assigned randomly into two groups, 170 patients for each group. Cesarean section rate in continued and discontinued group were 31.8% and 27.7%, respectively ( p = 0.40). The infusion of intravenous fluid in CG group was stopped due to non-reassuring fetal heart rate pattern in 15 women and total oxytocin doses used were significantly higher than that in DG group. In DG group, additional oxytocin was required due to poor uterine contraction. Duration of each stage of labor, maternal complications and adverse neonatal outcomes were not significantly different. There were only two cases of postpartum hemorrhage in discontinued group that was successful managed by medical treatment. Conclusion: There was not sufficient evidence to support whether discontinuation or continuation of oxytocin in active phase of labor influenced cesarean section rate. However, higher doses of oxytocin used was found in continuation group. Future well-randomized design with enough sample size is needed.