Cahill AG, et al. - In this randomized clinical trial, researchers ascertained if higher rates of spontaneous vaginal delivery and lower rates of maternal and neonatal morbidities can be had with immediate vs delayed pushing. They observed that the timing of second stage pushing efforts did not influence the rate of spontaneous vaginal delivery among nulliparous women receiving neuraxial anesthesia. These discoveries might help inform decisions about the preferred timing of second stage pushing efforts.

Methods

• Between May 2014 and December 2017, nulliparous women at or beyond 37 weeks’ gestation admitted for spontaneous or induced labor with neuraxial analgesia at 6 US medical centers were included in this pragmatic randomized clinical trial.
• For the primary outcome, the interim analysis suggested futility and recruitment was terminated with 2,414 of 3,184 planned participants.
• Follow-up ended January 4, 2018.
• When study participants reached complete cervical dilation, randomization occurred; the immediate group participants (n = 1,200) started pushing immediately, and delayed group participants (n = 1204) were told to wait an hour.
• Spontaneous vaginal delivery was the primary outcome.
• Total duration of the second stage, duration of active pushing, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, chorioamnionitis, endometritis, perineal lacerations (≥second degree), and a composite outcome of neonatal morbidity that included neonatal death and 9 other adverse outcomes were the included secondary outcomes.

Results

• According to the findings obtained, among 2,414 women randomized (mean age, 26.5 years), 2,404 (99.6%) completed the trial.
• It was observed that the rate of spontaneous vaginal delivery was 85.9% in the immediate group vs 86.5% in the delayed group, and was not significantly different (absolute difference, -0.6% [95% CI, -3.4% to 2.1%]; relative risk, 0.99 [95% CI, 0.96 to 1.03]).
• No significant difference was found in 5 of the 9 prespecified secondary outcomes reported, including the composite outcome of neonatal morbidity (7.3% for the immediate group vs 8.9% for the delayed group; between-group difference, -1.6% [95% CI, -3.8% to 0.5%]) and perineal lacerations (45.9% vs 46.4%, respectively; between-group difference, -0.4% [95% CI, -4.4% to 3.6%]).
• Compared with the delayed group (102.4 vs 134.2 minutes, respectively; mean difference, -31.8 minutes [95% CI, -36.7 to -26.9], P < .001), the immediate group had significantly shorter mean duration of the second stage, in spite of a significantly longer mean duration of active pushing (83.7 vs 74.5 minutes; mean difference, 9.2 minutes [95% CI, 5.8 to 12.6], P < .001), lower rates of chorioamnionitis (6.7% vs 9.1%; between-group difference, -2.5% [95% CI, -4.6% to -0.3%], P=.005), and fewer postpartum hemorrhages (2.3% vs 4.0%; between-group difference, -1.7% [95% CI, -3.1% to -0.4%], P=.03).