Discontinuation of oxytocin in active phase of labor associated with decreased risk of cesarean delivery: Study
Synthetic oxytocin OT, a peptide hormone capable of stimulating uterine contractions, is one of the most common pharmacologic agents used in induction of labor (IOL). Among low-risk nulliparous patients with spontaneous labor, more than 40% receive OT augmentation. The growing rate of IOL emphasizes the need to optimize protocols for IOL and augmentation of labor. OT is frequently used to decrease the total duration of labor and complications associated with prolonged labor, including chorioamnionitis, postpartum hemorrhage, and cesarean delivery (CD). However, OT has also been associated with uterine tachysystole, which is a known risk factor for significant fetal oxygen desaturations, non reassuring fetal heart rate characteristics, and neonatal acidemia. When used for the induction or augmentation of labor, OT is frequently continued until delivery while titrating the dosage to the frequency of uterine contractions. Discontinuation of OT during the active phase of labor has been proposed as an option to reduce the duration of exposure to this medication and associated complications, specifically uterine tachysystole and non reassuring fetal heart rate characteristics, as well as the costs associated with labor management.
The study objective was to determine if oxytocin discontinuation in the active phase of labor impacts the rate of cesarean delivery compared to continuation of oxytocin. 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). 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. Authors 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.
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.
This systematic review and metaanalysis demonstrated a decreased risk of CD among patients who discontinued OT administration in the active phase of labor. Uterine tachysystole and nonreassuring fetal heart rate tracing also occurred less frequently among patients assigned to discontinuation of OT. Discontinuation of OT was associated with an approximate 30-minute increase in active phase duration and approximate 6-minute increase in duration of second stage of labor. This study calls into question the routine practice of continuing OT administration until delivery among patients undergoing induction or augmentation of labor.
This meta-analysis of randomized controlled trials demonstrated that discontinuation of OT in active labor lowers the risk of CD and only lengthens labor by 30 minutes. More than two thirds of patients will not require reinitiation of OT after discontinuation in the active phase. Although the pooled analysis suggests a beneficial effect, this finding is dependent on the inclusion of studies with concerns regarding trustworthiness. Additional large, blinded trials among patients undergoing IOL for medical indications should be performed to better elucidate the role of OT in active labor management among patients at elevated risk for CD.
Source: Julia Whitley, Julia Burd, Michelle Doering, American Journal of Obstetrics & Gynecology JULY 2025; https://doi.org/10.1016/j.ajog.2025.03.015
