Epidural analgesia is the most effective and preferred form of pain relief in labor for many woman. However, some studies have reported an association between epidural analgesia and a prolongation of the second stage of labor and an increased risk of instrumental vaginal delivery. The concentration of local anesthetic used in many of these studies was greater than is commonly used today, though, resulting in a denser block than that experienced by most women receiving epidural labor analgesia in current practice. Other studies have shown that maternal position during the second stage of labor could also affect the risk of instrumental vaginal delivery. The current study, Birth in the Upright Maternal Position with Epidural in Second Stage (BUMPES) trial, aimed to determine whether being upright during the second stage of labor in nulliparous women receiving low dose epidural analgesia increased the rate of spontaneous vaginal birth compared with women who were lying down.