The effect of early oxytocin augmentation in labor: a meta-analysis.

OBJECTIVE To estimate the effects of early augmentation with oxytocin for slow progress of labor on the delivery method and on indicators of maternal and neonatal morbidity. DATA SOURCES We conducted electronic database searches of PubMed, MEDLINE, EMBASE, and the Cochrane Library for articles published through February 2009 using the keywords "oxytocin," "augmentation," "active management of labor," "cesarean section," and "labor." Primary authors were contacted directly if the data sought were unavailable. METHODS OF STUDY SELECTION We included randomized controlled trials comparing early oxytocin augmentation with a more conservative approach to care in labor. We included only those studies in which membrane management was similar in the two groups. Early oxytocin augmentation was defined as immediate oxytocin administration when dystocia was identified. Data were extracted by two authors independently and evaluated for potential sources of bias. Relative risk (RR) and 95% confidence interval (CI) were calculated using fixed and random effects models. TABULATION, INTEGRATION, AND RESULTS Nine trials with 1,983 women met the inclusion criteria. Early oxytocin was associated with an increase in the probability of spontaneous vaginal delivery (RR 1.09, 95% CI 1.03-1.17). For every 20 patients treated with early oxytocin augmentation, one additional spontaneous vaginal delivery is expected. Although the point estimate for the effect on cesarean delivery (RR 0.87, 95% CI 0.71-1.06) and on operative vaginal delivery (RR 0.84, 95% CI 0.70-1.00) showed modest protective effects, the CIs for both estimates included the null effect. A decrease in antibiotic use (RR 0.45, 95% CI 0.21-0.99) was observed with early intervention. Early oxytocin was associated with an increased risk of hyperstimulation (RR 2.90, 95% CI 1.21-6.94) without evidence of adverse neonatal effects. Women in the early oxytocin group reported higher levels of pain and discomfort in labor. CONCLUSION Early oxytocin for augmentation in labor is associated with an increase in spontaneous vaginal delivery.