Effect of Second-Stage Pushing Timing on Postpartum Pelvic Floor Morbidity: A Randomized Controlled Trial

Objective: To assess whether immediate or delayed pushing in the second-stage results in higher risk of pelvic floor morbidity. Methods: This study was a planned secondary aim of a multicenter randomized clinical trial that included nulliparous patients at 37 weeks of gestation or greater in labor with neuraxial analgesia. Participants were randomized in the second stage to initiate pushing immediately or wait 60 minutes before pushing. Participants had pelvic floor assessments at 1-5 days postpartum, 6 weeks postpartum, and 6 months postpartum. Rates of perineal lacerations, pelvic organ prolapse quantification (POP-Q) measures, and scores on validated symptom-specific distress and quality-of-life questionnaires (PFDI-20 [Pelvic Floor Distress Inventory], PFIQ [Pelvic Floor Impact Questionnaire], FISI [Fecal Incontinence Severity Index], and MMHQ [Modified Manchester Health Questionnaire]) were compared. It was estimated that 630 participants would provide more than 80% power to detect a 40% difference in second-degree or greater perineal lacerations and approximately 80% power to detect a 40% difference in stage 2 or greater pelvic organ prolapse (POP). Results: Among 2,414 participants in the primary trial conducted between May 19, 2014, and December 16, 2017, 941 (39%) had pelvic floor assessments: 452 immediate pushing and 489 delayed pushing. The mean age was 24.8 years, and 93.4% had vaginal delivery. There were no significant differences in perineal lacerations at delivery and POP at 6 weeks and 6 months postpartum. Changes from baseline in total and subscale scores for the PFDI-20, the PFIQ, and the MMHQ were not significantly different at 6 weeks postpartum and 6 months postpartum. The change in FISI score was higher in the immediate pushing group at 6 months (2.9±5.7 vs 2.0±4.5, difference 0.9, P=.01), but less than the minimum important difference of 4. Conclusion: Among nulliparous patients in the second stage with neuraxial analgesia, immediate pushing, compared with delayed pushing, did not increase perineal lacerations, POP-Q measures, or patient-reported pelvic floor symptoms at 6 weeks and 6 months postpartum.