Anesthesia during labor involves achieving a good balance between relieving pain and allowing the normal progression of labor.
Motor nerves control the muscles that contract the uterus during labor and delivery. Motor nerves, as well as sensory nerves, are affected by medications that block pain. Epidural and spinal blocks are methods of pain relief that block pain sensation with limited motor nerve blockage in comparison to intravenous medications. However, no current drug therapy provides optimal pain relief without some degree of temporary motor nerve blockage. Studies show that epidural and spinal anesthesia do decrease slightly the rate of spontaneous vaginal delivery.
Regional anesthesia consists of epidural or spinal anesthesia, or a combination epidural-spinal. Epidural anesthesia and spinal anesthesia are currently the most popular choices for laboring women in the . These methods provide pain relief while minimizing the suppression of motor function that can hinder a spontaneous vaginal delivery. In addition, epidural methods allow for easy administration of additional anesthetic during the late second stage of labor or if cesarean section becomes required. Newer epidural techniques use dilute anesthetic agents mixed with narcotics to provide excellent pain relief with limited motor blockade (walking epidural). The main side effect with this approach is itching. The of Obstetricians and Gynecologists believes that any women with labor pain should be offered adequate pain relief.