The impact of extending the second stage of labor on repeat cesarean section and maternal and neonatal outcome.

OBJECTIVE

To evaluate the effects of extending the second stage of labor in women attempting a trial of labor after a cesarean section (TOLAC).

METHOD: A retrospective cohort study comparing maternal and neonatal outcomes following TOLAC over two periods: period I whose prolonged second stage was considered 2 h, and period II whose prolonged second stage was considered 3 h. The primary outcome was repeat cesarean delivery (CD) rate.

RESULTS

Incidence of repeat CD was significantly lower in period II (18.1% vs 29.7%, P < 0.001). Incidence of uterine rupture was significantly higher in period II (P < 0.001). Instrumental delivery rates were significantly higher in period II (26.2% vs 15.6%, odds ratio [OR] 1.67, 95% CI 1.21-3.56, P < 0.001). Rates of third- and fourth-degree perineal lacerations, chorioamnionitis, and length of hospital stay were similar between groups. Incidence of fetal acidemia was significantly higher in period II (1.5% vs 0.7%, OR 2.14, 95% CI 1.32-5.63, P < 0.001), and incidence of neonatal intensive care unit (NICU) admission was significantly higher (2.5% vs 1.6%, P = 0.004).

CONCLUSION

Extension of the second stage of labor is associated with a decrease in repeat CD rate with a concomitant increase in instrumental delivery rates, uterine rupture, fetal acidemia, and NICU admissions. These findings may warrant further consideration of allowing a prolonged second stage in patients attempting TOLAC.