Labor analgesia: An update on the effect of epidural analgesia on labor outcome

Following the introduction of epidural for labor analgesia, debate has centered on the issue of its effect on outcome of labor; in terms of length of labor and increase in the rate of instrumental vaginal delivery and cesarean section (CS). There is no ideal study on the effect of epidural analgesia (EA) on the outcome of labor due to logistic problems in randomization, blinding and getting a control group; as a result these queries are partly answered. Despite these problems, it has been established that labor epidural has minimal effect on progress of established labor and maternal request should be a sufficient indication to start an epidural. Although instrumental vaginal delivery is probably increased with epidural but obstetrician practice, pain free patient and teaching opportunity are likely factors increasing the incidence. Maternal-fetal factors and obstetric management and not the use of EA are the most important determinants of the CS rate. The purpose of this review is to summarize data from controlled trials addressing the question of whether neuraxial labor analgesia causes an increased risk of CS or rate of instrumental delivery. In addition, the review discusses whether the timing of initiation of analgesia influences the mode of delivery.