High- versus Low-dose Oxytocin Regimens for Labor Augmentation: A Systematic Review and Meta-analysis.
Review
Overview
abstract
OBJECTIVE: To assess whether high- versus low-dose oxytocin regimens for labor augmentation are associated with differential risk for low Apgar score, neonatal acidosis, and other adverse labor outcomes. DATA SOURCES: We searched electronic databases (MEDLINE, EMBASE, the Cochrane Library, CINAHL, Scopus, ClinicalTrials.gov) from inception up to March 2024 using combinations of the following keywords: "oxytocin," "oxytocin regimen," "oxytocin protocol," "oxytocin dosage," "active management," "high dose protocol," "low dose protocol," "augmentation of labor." STUDY ELIGIBILITY CRITERIA: We included quasi-randomized and randomized controlled trials comparing continuous oxytocin infusion with high-dose regimens (i.e., intervention group) versus low-dose regimens (i.e., control group) in nulliparous or multiparous patients undergoing augmentation of labor. High-dose regimens were defined as starting oxytocin dose of 4 mU/min or higher and increasing by increments of 3-7 mU/min every 15 to 40 minutes. Low-dose regimens were defined as starting oxytocin dose of less than 4 mU/min and increasing by increments of 1-2 mU/min every 15 to 40 minutes (PROSPERO CRD42024500197). APPRAISAL AND SYNTHESIS METHODS: The co-primary outcomes were incidence of Apgar score <7 at 5 minutes and umbilical arterial pH <7.00. Secondary outcomes included cesarean delivery and chorioamnionitis. We performed random-effect head-to-head meta-analyses to compare high- versus low-dose strategies, reporting summary risk ratio (RR) with 95% confidence interval (CI). RESULTS: Ten randomized and quasi-randomized controlled trials of 5,508 total pregnancies met inclusion criteria and were included in the meta-analysis. There was no difference in risk for the co-primary outcomes of Apgar score <7 at 5 minutes (relative risk [RR] 0.94, 95% confidence interval [CI] 0.60-1.46) and umbilical arterial pH <7.00 (RR 0.77, 95% CI 0.50-1.20). There was also no difference in risk for cesarean delivery (RR 0.83, 95% CI 0.67-1.02). High-dose oxytocin regimens were associated with significantly lower risk of chorioamnionitis (RR 0.70, 95% CI 0.57-0.84, number needed to treat=25) and higher risk of tachysystole (RR 1.32, 95% CI 1.21, 1.43; p<0.001). CONCLUSION: When used for labor augmentation, high-dose oxytocin regimens decrease risk for chorioamnionitis compared to low-dose regimens, without affecting risk for low Apgar score, neonatal acidosis, or cesarean delivery.
