Delayed versus immediate pushing in the second stage of labor in women with neuraxial analgesia: a systematic review and meta-analysis of randomized controlled trials

Objective: The aim of this systematic review and meta-analysis of randomized controlled trials was to evaluate the effect of delayed versus immediate pushing in the second stage of labor on mode of delivery and other outcomes in women with neuraxial analgesia. Data sources: The research was conducted using MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and the Cochrane Library as electronic databases, from the inception of each database to August 2019. No restrictions for language or geographic location were applied. Study eligibility criteria: Selection criteria included only randomized controlled trials in pregnant women randomized to either delayed or immediate pushing during the second stage of labor. Study appraisal and synthesis methods: The primary outcome was mode of delivery. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I2 (Higgins I2) value of greater than 0% was used to identify heterogeneity. Results: Twelve randomized controlled trials, including 5445 women with neuraxial analgesia randomized to delayed versus immediate pushing during the second stage of labor, were included in the meta-analysis. Of the 5445 women included in the meta-analysis, 2754 were randomized to the delayed pushing group and 2691 to the immediate pushing group. No significant difference between delayed and immediate pushing was found for spontaneous vaginal delivery (80.9% versus 78.3%; relative risk, 1.05; 95% confidence interval, 1.00−1.10; 12 randomized controlled trials, 5540 women), operative vaginal delivery (12.8% versus 14.6%; relative risk, 0.89; 95% confidence interval, 0.75−1.08; 11 randomized controlled trials, 5395 women), and cesarean delivery (6.9% versus 7.9%; relative risk, 0.89; 95% confidence interval, 0.73−1.07; 11 randomized controlled trials; 5395 women). Women randomized to the delayed pushing group had a significantly shorter length of active pushing (mean difference, −27.54 minutes; 95% confidence interval, −43.04 to −12.04; 7 randomized controlled trials, 4737 women) at the expense of a significantly longer overall duration of the second stage of labor (mean difference, 46.17 minutes; 95% confidence interval, 32.63−59.71; 8 studies; 4890 women). The incidence of chorioamnionitis (9.1% versus 6.6%; relative risk, 1.37, 95% confidence interval, 1.04−1.81; 1 randomized controlled trial, 2404 women) and low umbilical cord pH (2.7% versus 1.3%; relative risk, 2.00; 95% confidence interval, 1.30−3.07; 5 randomized controlled trials, 4549 women) were significantly higher in the delayed pushing group. Conclusion: In women with spontaneous or induced labor at term with neuraxial analgesia, delayed pushing in the second stage does not affect the mode of delivery, although it reduces the time of active pushing at the expense of a longer second stage. This prolongation of labor was associated with a higher incidence of chorioamnionitis and low umbilical cord pH. Based on these findings, delayed pushing cannot be routinely advocated for the management of the second stage.