Reduced risk of cesarean delivery with oxytocin discontinuation in active labor: a systematic review and meta-analysis

Objective: Our objective was to determine if oxytocin discontinuation in the active phase of labor impacts the rate of cesarean delivery compared to continuation of oxytocin. Data sources: This study was a systematic review and meta-analysis of randomized controlled trials. A research librarian performed a database search using a combination of standardized terms and keywords related to oxytocin discontinuation and stages of labor from database inception until February 2024. This protocol was registered in The International Prospective Register of Systematic Reviews (PROSPERO). Study eligibility criteria: Randomized controlled trials of pregnant patients who received oxytocin for induction or augmentation of labor, whose outcomes compared discontinuation and continuation of oxytocin in active labor, were included. We defined “active phase of labor” as defined by each trial. Nonrandomized trials, quasi-randomized trials, and animal models were excluded. The primary outcome was the rate of cesarean delivery. Secondary maternal outcomes included postpartum hemorrhage, total blood loss, and infectious outcomes. Secondary neonatal outcomes included Apgar score at 5 minutes <7, umbilical arterial pH <7.10, neonatal therapeutic hypothermia, neonatal intensive care unit admission, neonatal resuscitation at birth, and neonatal death. Study appraisal and synthesis methods: The risk of bias in each study was assessed using the guidelines outlined in the Cochrane Handbook for Systematic Reviews of Interventions. Heterogeneity was measured using Higgins I². Meta-analysis was performed in Review Manager 5.4.1 and StataSE 16 to determine summary treatment effects in terms of relative risk or mean difference with 95% confidence intervals. The adherence of each included trial to the trustworthiness criteria outlined by the OBGYN Editors' Integrity Group was assessed, and a leave-1-out analysis was performed to evaluate the effect of studies with concerns regarding trustworthiness. Results: Fifteen randomized controlled trials, including 5734 patients, were ultimately included in the meta-analysis. The rate of cesarean delivery, reported in 13 studies, was lower with discontinuation of oxytocin in the active phase of labor (relative risk=0.80; 95% confidence interval, 0.66–0.97; 95% prediction interval, 0.38–1.22). Discontinuation of oxytocin was also associated with a lower risk of uterine tachysystole (relative risk=0.45; 95% confidence interval, 0.34–0.60; I², 26%), and nonreassuring fetal heart rate tracing (relative risk=0.64; 95% confidence interval, 0.49–0.82; I², 41%). Discontinuation of oxytocin increased the duration of active labor by an average of 30 minutes and second stage of labor by an average of 6 minutes. Conclusion: Although associated with an extension of labor by half an hour, discontinuation of oxytocin in the active phase of labor was associated with a 20% decreased risk of cesarean delivery and a lower risk of uterine tachysystole and nonreassuring fetal heart rate tracing. While the pooled analysis suggests a beneficial effect, this finding is dependent on the inclusion of studies with concerns regarding trustworthiness.