Perinatal outcome in relation to second-stage duration

OBJECTIVE: The second stage of labor has been thought of as a time of particular asphyxial risk for the fetus. This perceived risk has been invoked to justify arbitrary time limits and high rates of operative vaginal delivery. The purpose of this study was to determine whether perinatal outcome worsened as the second stage lengthened. STUDY DESIGN: Over a 5-year period at one university teaching hospital, 6041 nulliparous women reached the second stage of labor with a live singleton cephalic fetus with birth weight ≥2500 gm. A retrospective review of perinatal morbidity and mortality was performed and the results related to the duration of the second stage. RESULTS: The second stage lasted>3 hours in 11% of nulliparous women and>5 hours in 2.7%. There were no perinatals death unrelated to anomaly. There was no significant relationship between second-stage duration and low 5-minute Apgar score, neonatal seizurs, or admission to the neonatal intensive care unit. CONCLUSION: Operative intervention in the second stage is not warranted merely because some set number of hours has elapsed.