Impact of Central Neuraxial Analgesia on the Progress of Labor

Abstract

E pidural and spinal anesthesia have become the de facto gold standard for pain relief during labor and delivery. Multiple randomized controlled trials comparing epidural analgesia with systemic opioid analgesia or nitrous oxide have demonstrated lower pain scores and higher patient satisfaction with neuraxial analgesia [1–4]. Furthermore, neuraxial analgesia has been shown to impart significant safety and physiologic benefits to mother and fetus [5–8]. As such, the use of neuraxial techniques for labor analgesia has progressively increased over the past 3 decades. In the United States, the percentage of women receiving neuraxial analgesia for labor had risen to 77% in 2001 from 21% in 1981; in the United Kingdom, approximately 36% of parturients chose epidural analgesia for labor in 2007/2008 [9,10]. Despite the increased use and proposed benefits of neuraxial labor analgesia, there has been significant controversy regarding the impact of neuraxial analgesia on the progress of labor and mode of delivery. Although it seems at first glance that parturients who have neuraxial analgesia for labor have higher cesarean delivery rates, higher rates of instrumental vaginal delivery, and longer duration of labor, the cause-effect relationship of these associations remains controversial and unclear. The purpose of this article is to summarize the literature exploring this topic to arrive at a clearer understanding of how, and to what extent, neuraxial analgesia impacts labor and delivery.