An association between severe labor pain and cesarean delivery

The relationship between epidural analgesia and cesarean delivery remains c ontroversial. Several studies have documented an association, although othe rs have not. This inconsistency may result from an association between seve re labor pain and dystocia. We hypothesized that dystocia causes severe lab or pain, such that more epidural medication is required to maintain comfort . We examined the relationship between labor outcome and severe pain, defin ed by the number of supplemental epidural boluses. We retrospectively revie wed the anesthesia records of 4493 parturients who received small-dose labo r epidural analgesia. An independent association was found between operativ e delivery and maternal age, body mass index, nulliparity, fetal weight, in duction of labor, and the number of boluses required during labor. By using multivariate analysis, the odds ratio of cesarean delivery among women who required at least three boluses was 2.3 compared with those who required t wo boluses or less. No association was found between the concentration of b upivacaine in the epidural infusion and operative delivery. Because women w ith cesarean deliveries appeared to have more pain, degree of labor pain ma y be a confounding factor in studies examining epidural analgesia and outco me. Implications: This is a retrospective observational study demonstrating an association between labor pain and cesarean delivery. Our results provi de an alternative explanation of why epidural analgesia is associated with cesarean delivery.