The impact of epidural analgesia on the duration of the second stage of labor.

BACKGROUND: We aimed to describe the length of second stage of labor in a contemporary cohort. We calculated the 5th, 50th, and 95th percentiles for second-stage length stratified by parity and epidural analgesia use and evaluated the effect of labor induction and oxytocin augmentation in our cohort.

METHODS: We did a retrospective analysis of all live, singleton, term vaginal deliveries in one tertiary hospital. Multivariate linear regression was used to evaluate second-stage duration confounders. First, we calculated the second-stage length and presented it as 5th, 50th, and 95th percentiles stratified by epidural analgesia and parity. Second, we evaluated the effect of labor induction and oxytocin augmentation on second-stage length, and third, we determined the demographic and obstetrical confounders that affected second-stage length.

RESULTS: Overall, 15 500 deliveries were included. Nulliparity, oxytocin augmentation, epidural use, birthweight, labor induction, lower body mass index, and higher maternal age were found to be significantly associated with prolongation of the second stage. Epidural use was associated with an additional 82 minutes for the 95th percentile for both nulliparas and multiparas and tripled the rate of prolonged second stage for the entire cohort. Labor induction was associated with clinically significant prolongation of the second stage in nulliparas with epidural analgesia only. Oxytocin was associated with longer duration of the second stage for nulliparas, regardless of epidural use.

DISCUSSION: Our findings suggest a significant prolongation of the second stage in women receiving epidural analgesia. Recommendations for management of second stage should be reconsidered by contemporary data.