Second stage of labor and epidural use: a larger effect than previously suggested.

Objective: To examine the length of second stage of labor with and without an epidural during labor.

Methods: This was a retrospective cohort study of 42,268 women who delivered vaginally with normal neonatal outcomes. Median lengths and 95th percentiles of second stage of labor were compared by epidural use with stratification by parity. Statistical comparisons were performed using the Kruskal-Wallis test and Kaplan-Meier survival analysis.

Results: Compared with women without epidural use, the 95th percentile length of second stage for nulliparous women was 197 minutes without epidural and 336 minutes with epidural (P<.001), a difference of 2 hours and 19 minutes. For multiparous women, the 95th percentile length of second stage was 81 minutes without epidural and 255 minutes with epidural (P<.001), a difference of 2 hours and 54 minutes.

Conclusion: Although recommendations for intervention during the second stage of labor have been made based on a 1-hour difference in the setting of epidural use, it appears that the 95th percentile duration is actually more than 2 hours longer with epidural during labor for both nulliparous and multiparous women.