Adverse outcomes associated with time from neuraxial anesthesia to delivery among non-labor cesarean

OBJECTIVE Prior studies showing an inverse association between time from spinal anesthesia to delivery and umbilical artery pH were relatively small cohorts or included only spinal anesthesia. In a large cohort of unlabored cesarean deliveries, we further investigated this association. STUDY DESIGN This is a secondary analysis of a retrospective cohort study of singleton, term, non- anomalous pregnancies delivered by non-labor cesarean with neuraxial anesthesia inclusive of spinal, epidural, or combined spinal epidural. We assessed outcomes with time intervals from neuraxial placement to delivery: <20 minutes, 20-39 minutes, 40-59 minutes, and ≥60 minutes. The primary outcome was umbilical artery pH <7.1. We further analyzed the time intervals for surgical procedural steps among neonatal umbilical artery pH cohorts: ≤7.00, 7.01-7.10, 7.11-7.20, 7.21-7.30; and ≥7.31. Multivariable logistic regression adjusting for baseline confounders was used to determine strength of association. RESULTS Of the 5255 cesarean deliveries, 645 (12.3%) delivered within 20 minutes, 4067 (77.4%) delivered between 20-39 minutes, 468 (8.9%) delivered between 40-59 minutes, and 75 (1.4%) delivered ≥60 minutes from neuraxial anesthesia. Increased time from neuraxial placement to delivery was associated with umbilical artery pH<7.1 and <7.2, umbilical artery base deficit>8, and meconium-stained amniotic fluid (all p<0.05). After adjusting for confounders and using <20-minutes as the reference, increased time from neuraxial placement to delivery was no longer associated with adverse outcomes. There was an inverse relationship with pH and time from neuraxial placement to delivery, skin incision to uterine incision, and uterine incision to delivery (all p<0.01). CONCLUSION Our study suggests that although increased time from neuraxial anesthesia to delivery is associated with lower UA pH, these findings are significantly affected by clinical factors such as BMI, hypertension or diabetic disorders, type of neuraxial anesthesia, number of prior cesarean, and surgical factors such as duration of procedural steps.