The Association of Latent Labor and Classical Cesarean Delivery [2P

Abstract

INTRODUCTION: Labor prior to cesarean delivery is thought to be a protective factor against classical incision at <28 weeks gestation, ostensibly from development of the lower uterine segment. This study aims to determine if latent labor has a similar secondary benefit to reduce classical cesarean deliveries at an early gestational age. METHODS: In this retrospective cohort study, patients with a singleton pregnancy between 24 and 31 weeks gestational age undergoing cesarean delivery at a single, tertiary academic medical center were enrolled between January 2011 and December 2015. Stages of labor were defined as none, latent phase (final dilation <6cm), and active phase (final dilation >/= 6cm). The primary outcome was type of uterine incision. RESULTS: For 263 eligible patients, the rate of classical cesarean delivery was 53%. This varied significantly by gestational age (77% at 24-27 weeks vs 32% at 28-31 weeks; p<0.0001). Other significant factors associated with classical incision included smaller birthweight, chorioamnionitis, and fetal malpresentation (p<0.05). Labor was not significantly associated with a reduction in the odds of classical incision (OR 0.79, 95% CI 0.49-1.29). Stratification by stage of labor also did not show a significant difference in rate of classical incision for none, latent, and active labor for all patients (55%, 50%, and 49%, respectively) or for 24-27 weeks (78%, 79%, and 71%, respectively). No difference was observed between spontaneous and induced labor or by provider specialty and experience. CONCLUSION: In this preliminary analysis, labor, regardless of stage, was not associated with reduction in the odds of classical cesarean delivery.