Cesarean delivery outcomes after a prolonged second stage of labor

Objective: We hypothesized that prolonged second stage of labor increases the incidence of unintentional hysterotomy extensions at cesarean delivery. Study Design: A retrospective cohort of term pregnant women who underwent primary cesarean delivery after failed second stage of labor at Stanford University was assessed for hysterotomy extensions and other maternal and neonatal morbidities. Groups included second stage length of 1-3 hours and >4 hours. Data were analyzed with the use of chi-square and Fisher's exact tests. Results: Of the 239 women who were studied, the second stage of labor lasted 1-3 hours in 82 patients and >4 hours in 157 patients. Prolonged second stage of labor was associated with unintentional hysterotomy extensions (40% vs 26%; P = .03), particularly to the cervix (29% vs 5%; P = .005), and with surgery that lasted >90 minutes (9% vs 1%; P = .01). The incidence of hysterotomy extensions was associated positively with the length of the second stage. Other maternal and neonatal morbidities were similar between groups. Conclusion: Prolonged second stage of labor is associated with an increase in unintentional hysterotomy extensions at cesarean delivery and prolonged operative time. The future risk of hysterotomy extensions merits further investigation.