Mode of Delivery after Epidural Analgesia in a Cohort of Low-Risk Nulliparas

Background: Although epidural analgesia is widespread and very effective for alleviating labor pain, its use is still controversial, as the literature is inconsistent about the risk of adverse birth outcome after administration of epidural analgesia. The aim of this study was to explore associations between epidural analgesia and mode of delivery. Methods: Data were obtained from a prospective cohort from nine Danish labor wards and comprised 2,721 term nulliparous women with spontaneous onset of labor and a singleton fetus in cephalic presentation. Information about epidural analgesia, mode of delivery, and birth complications was obtained by the staff attending labor. Additional information was provided from self-administered questionnaires in gestational week 37. Multiple logistic regression analyses were used to estimate the association between epidural analgesia and birth outcomes. Results are presented as crude and adjusted odds ratios (OR [95% CI]). Results: Of the total cohort, 21.6 percent required epidural analgesia, 8.7 percent had emergency cesarean section, and 14.9 percent had vacuum extraction. Women with epidural analgesia had a higher risk of emergency cesarean section (adjusted OR: 5.8; 95% CI: 4.1-8.1), and vacuum extraction (adjusted OR: 1.7; 95% CI: 1.3-2.2). In a subgroup of the cohort with a very low overall risk of cesarean section, 3.4 percent had emergency cesarean section and an increased risk of emergency cesarean section was also found in this group (adjusted OR: 3.5; 95% CI: 1.5-8.2). Conclusions: In nulliparous women of a very low-risk population, use of epidural analgesia for labor pain was associated with higher risks of emergency cesarean section and vacuum extraction. (BIRTH 38: 4 December 2011)