485: Risks during cesarean delivery after prolonging the second stage of labor

Abstract

Perinatal risks regardless of mode of delivery are known to increase with time spent in the second stage (SS). However, it is unknown if risks specific to cesarean delivery also escalate with time. The aim of this study was to quantify perinatal morbidities associated with cesarean delivery by length of second stage. Retrospective cohort study of nulliparous women with singleton gestations, cephalic presentation and term cesarean deliveries during the SS of labor using the Consortium on Safe Labor database. Exclusion: stillbirth, contraindications to vaginal delivery. Length of SS was grouped by hours: 3, 3-4, 4-5, 5-6, and 6. Demographic and clinical variables were compared by group. Univariable and multivariable analyses of maternal and neonatal outcomes of interest were performed to elucidate the independent effect of length of SS on these outcomes. The primary outcome was a composite of maternal morbidities. Secondary outcomes were individual perinatal morbidities. 6,273 women were evaluated by length of SS: 3,652 (58.2%) 3 hours, 854 (13.6%) 3-4 hours, 618 (9.9%) 4-5 hours, 397 (6.3%) 5-6 hours, and 752 (12.0%) 6 hours. Maternal composite outcome were not statistically different between groups (Table, Figure). Extended maternal length of stay (>5 days), increased birthweight and lower rates of general anesthesia were significantly associated with increased length of SS. Significantly higher odds of hemorrhage (aOR 1.50; 95% CI: 1.05 - 2.13) and 1-minute APGAR score ≤ 5 (aOR 1.67; 95% CI: 1.17 – 2.40) were found when comparing women with SS 3-4 hours vs 3 hours, but this finding was not detected after 4 hours. Chorioamnionitis, wound complications and thrombosis did not increase over time. Composite neonatal morbidity was not statistically different between groups (Figure). After 3 hours of SS, cesarean delivery may accrue more risk for patients. Counseling women about duration of SS should include a discussion of increased risks of cesarean delivery over time; specifically, increased risk of hemorrhage, maternal length of stay and lower 1 minute APGAR score.View Large Image Figure ViewerDownload Hi-res image Download (PPT)