Duration of the second stage of labor in multiparous women: maternal and neonatal outcomes.

Abstract

This study was undertaken to examine perinatal outcomes associated with the second stage of labor in multiparous women. This is a retrospective cohort study of all term, cephalic, singleton births delivered by multiparous women between 1991 and 2001. Duration of the second stage of labor was stratified into hourly intervals: 0-1 hour, 1-2 hours, 2-3 hours, and 3 hours or longer. Perinatal outcomes were analyzed by using chi2 test and multivariable logistic regression models, by using P<.05 and 95% CI to indicate statistical significance. Compared with women who delivered between the 0- and 2-hour interval, women with a second stage more than 3 hours had higher risks of operative vaginal deliveries (odds ratio = 13.27; 95% CI [9.38-18.8]), cesarean deliveries (odds ratio = 6.00; [4.06-8.86]), and maternal morbidity including third- or fourth-degree perineal lacerations, postpartum hemorrhage, and chorioamnionitis. Their neonates had higher risks of 5-minute Apgar score less than 7 (odds ratio = 3.63; 95% CI [1.77-7.43]), meconium stained amniotic fluid (odds ratio = 1.44; 95% CI [1.07-1.94]), admission to intensive care nursery (odds ratio = 2.08; 95% CI [1.15-3.77]), composite neonatal morbidity (odds ratio = 1.85; 95% CI [1.23-2.77]), and longer neonatal stay in the hospital (odds ratio = 1.67; 95% CI [1.11-2.51]). Multiparous women with a second stage of 3 hours or greater are at increased risks for operative deliveries, peripartum morbidity, and undesirable neonatal outcomes. These outcomes should be considered in the management of multiparous women with a second stage of labor beyond 3 hours.