Pushing the Limits: Perinatal Outcomes Beyond Prolonged Second Stage

Introduction Evaluate whether extremely prolonged second stage of labor in nulliparous women affects maternal and neonatal outcomes. Methods We performed a retrospective cohort study of term, nulliparous women with singleton gestations, epidural anesthesia, who reached 10 centimeters of cervical dilation. Exclusion criteria were intrauterine fetal demise, planned cesarean delivery or major fetal anomaly. Women were compared by length of second stage: 0-179 minutes (normal second stage), 180-299 (prolonged second stage) and ≥ 300 (extremely prolonged second stage). Primary outcome was incidence of spontaneous vaginal delivery (SVD). Secondary outcomes were maternal and neonatal outcomes. Results In total, 662 women were evaluated: 115 extremely prolonged second stage (EPSS), 116 prolonged second stage (PSS) and 430 normal second stage (NSS). Incidence of SVD was 93.3% in the NSS group, 86.2% in the PSS group and 50.4% in the EPSS group. The PSS group had a higher incidence of 3rd degree laceration. The EPSS group had a higher incidence of postpartum hemorrhage compared to the NSS group, 3rd degree laceration, neonatal CPAP use and composite neonatal outcome. Conclusions/Implications In nulliparous term women who reached 10 centimeters, the chance of SVD decreased by 55% after 3 hours and by 97% after 5 hours. However, most women delivered vaginally, with 70.4% delivering by SVD after 5 hours. The PSS group had similar maternal and neonatal outcomes as the NSS group; whereas the EPSS group had significantly worse outcomes. Risks and benefits of PSS vs EPSS should be weighed during clinical decision-making on the length of labor during the second stage