Association Between Time of Day of Delivery and Perinatal Outcomes [17L]. (May 2017) - Liu, Lilly
Abstract : INTRODUCTION: Prior work has demonstrated differences in cesarean-associated maternal morbidity based on time of delivery, but it remains unclear whether delivery mode or neonatal outcomes are associated with diurnal patterns. The objective was to determine if there is an association between delivery time and perinatal outcomes. METHODS: This is a retrospective cohort study of all nulliparous women delivering singleton, vertex, live births at ≥37 weeks gestation at a single center from 2014-15. Delivery time was dichotomized with nighttime deliveries designated as those occurring between 6pm and 6am. The primary outcome was delivery mode. Secondary outcomes included epidural use, labor augmentation, episiotomy and perineal lacerations, 5 minute Apgar < 7, cord umbilical artery pH < 7.0, and NICU admission. Bivariable and multivariable analyses were utilized for analyses. RESULTS: Of 7, 691 women eligible for inclusion, 3, 707 (48.2%) delivered during the night. Women undergoing night deliveries were marginally more likely to be undergoing induction of labor (20.1% vs 18.4%, p=0.06). Women delivering during the night were less likely to experience augmentation of labor (79.8% vs 81.6%, p=0.05) and had a higher frequency of cesarean delivery (20.6% vs 17.0%, p < 0.001). They were also more likely to have neonates with a 5-minute Apgar score < 7 (aOR 1.57, 95% CI 1.07-2.30) and umbilical artery pH < 7.0 (aOR 1.75, 95% CI 1.17-2.61). CONCLUSION: Among nulliparous women, delivery at night is associated with greater odds of cesarean delivery, low 5-minute Apgar score, and low umbilical artery pH.