Continuation versus discontinuation of intravenous oxytocin in the active phase of labour.

rationaleIntravenous oxytocin is widely used to induce labour or to augment labour (i.e. enhance contractions to promote progression), with approximately one-quarter of pregnant women at term receiving the medication. While continuous administration of intravenous oxytocin stimulation from induction until birth is recommended by most clinical guidelines, this may increase the risk of uterine hyperstimulation, foetal distress, and adverse maternal and neonatal outcomes. Discontinuation of oxytocin in the active phase of labour could reduce these risks without compromising labour progression. However, evidence from randomised trials is conflicting, and optimal management is unclear.

objectivesTo assess the effects of the discontinuation of intravenous oxytocin stimulation in pregnant women during the active phase of induced or augmented labour. SEARCH

methodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Scopus, and Web of Science Core Collection, as well as ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform. We also screened reference lists of included studies and relevant reviews, and contacted trial authors for additional data. No language or date restrictions were applied. The last search was conducted on 17 November 2025. ELIGIBILITY CRITERIA: We included randomised controlled trials comparing continuation versus discontinuation (or placebo) of intravenous oxytocin in the active phase of labour (≥ 4 cm cervical dilation) in term singleton pregnant women undergoing labour induction or augmentation. No restrictions to inclusion were applied regarding parity, maternal age, comorbidities, labour setting, or presence or absence of previous caesarean section. OUTCOMES: The critical outcome was caesarean section. Important maternal outcomes included instrumental vaginal birth (vacuum extraction or forceps delivery), postpartum haemorrhage, maternal infection, maternal satisfaction, duration of the active phase of labour, uterine hyperstimulation (tachysystole with abnormal CTG (cardiotocography)), and uterine tachysystole with normal CTG. Important neonatal outcomes included admission to neonatal unit, hypoxic ischaemic encephalopathy or therapeutic hypothermia, neonatal infection, perinatal death, acidotic cord blood gases (arterial pH < 7.10), and Apgar score < 7 at five minutes. RISK OF BIAS: Two review authors independently assessed the risk of bias for each trial using Cochrane's risk of bias tool RoB 1, following the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We assessed random sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential sources of bias. We resolved disagreements through discussion or by involving a third review author. We assessed potentially eligible and included trials using the Cochrane Pregnancy and Childbirth Trustworthiness Screening Tool. SYNTHESIS

methodsFor dichotomous outcomes, we calculated risk ratios (RR) with 95% confidence intervals (CIs). For continuous outcomes, we calculated mean differences (MDs) with 95% CIs. For our primary analysis, we used the fixed-effect model, implemented using the Mantel-Haenszel method for dichotomous outcomes and inverse variance for continuous outcomes. We prespecified random-effects meta-analysis as a secondary analysis to explore the robustness of the findings in the presence of between-study heterogeneity. We conducted sensitivity and subgroup analyses for the critical outcome only. We assessed statistical heterogeneity using Tau², I² and Chi² statistics. We evaluated the certainty of evidence using the GRADE approach for the prespecified outcomes included in our summary of findings table. INCLUDED STUDIES: During the study selection process, we placed 10 studies in the 'awaiting classification' category because we needed additional information to assess eligibility or trial trustworthiness. These studies could potentially change the review's conclusions once verified and incorporated. This review includes a total of nine trials evaluating nine comparisons and involving 4814 women. The overall risk of bias of included trials varied. Several studies were open label, and allocation concealment was unclear in some. The certainty of evidence ranged from high to low, mainly due to risk of bias, inconsistency, and imprecision across studies. SYNTHESIS OF

resultsDiscontinuation of oxytocin at the onset of the active phase of induced or augmented labour may make little or no difference to the risk of caesarean section compared with continuation (RR 0.98, 95% CI 0.85 to 1.13; I² = 5%; 8 studies, 4710 participants; low-certainty evidence). In a sensitivity analysis for the critical outcome excluding trials with high risk of bias in one or more domains, only one trial remained (RR 1.17, 95% CI 0.90 to 1.53; 1198 women). Discontinuation makes little or no difference to the risk of instrumental vaginal birth (RR 1.05, 95% CI 0.90 to 1.21; I² = 0%; 5 studies, 3776 participants; high-certainty evidence). The duration of the active phase of labour may be longer after discontinuation, with a mean difference of 34.72 minutes compared to continued stimulation, but the certainty of this evidence is very low (MD 34.72, 95% CI 26.34 to 43.11; I² = 82%; 8 studies, 4141 participants; very low-certainty evidence). Discontinuation may reduce uterine hyperstimulation (RR 0.65, 95% CI 0.55 to 0.77; I² = 56%; 3 studies, 1371 participants; low-certainty evidence). Discontinuation makes little or no difference to admission to a neonatal unit (RR 0.98, 95% CI 0.76 to 1.27; I² = 0%; 7 studies, 4606 participants; high-certainty evidence) or acidotic cord gasses at birth (arterial pH < 7.10) (RR 1.01, 95% CI 0.75 to 1.35; I² = 0%; 6 studies, 4086 participants; high-certainty evidence). Discontinuation probably makes little or no difference to the risk of having an Apgar score less than seven at five minutes (RR 0.92, 95% CI 0.40 to 2.11; I² = 0%; 5 studies, 2096 participants; moderate-certainty evidence). AUTHORS'

conclusionsDiscontinuation of oxytocin in the active phase of induced or augmented labour may have little or no effect on caesarean birth and has little or no effect on instrumental birth. It may reduce uterine hyperstimulation at the expense of a longer duration of the active phase of labour, but this evidence is of very low certainty. The discontinuation strategy appears safe for both mother and baby, provided that adequate monitoring of uterine activity and foetal heart rate is maintained.

fundingNone REGISTRATION: The protocol for this Cochrane review was published in November 2024.