New data points to slower course of labor

The second stage of labor, defined as the interval from complete cervical dilation through delivery of the fetus, presents many questions as well. There is a paucity of quality published data concerning what is normal, how long the stage should last, and how we should manage it. Historically, we have been taught to allow 2 hours of pushing for nulliparous women and 1 hour for multiparous women, when epidural anesthesia has not been administered, and to add an additional hour when epidural is used.

The 2014 ACOG-SMFM consensus statement recommends extending each of these limits by an hour, if maternal and fetal conditions permit, so that we allow at least 3 hours of pushing for nulliparous women and at least 2 hours for multiparous women before diagnosing arrest of labor in the second stage. Longer durations may be appropriate with the use of epidural anesthesia and on an individualized basis.

At this time, it is unclear whether there is any absolute maximum length of time beyond which all women in the second stage of labor should undergo cesarean delivery. We also still do not know the optimal technique for managing maternal pushing during the second stage. Should women with an epidural push right away or should they allow for a period of spontaneous descent? Many of the high-quality studies reported thus far that compare delayed and immediate pushing have limited applicability to current practice because they involved now-obsolete midpelvic forceps deliveries. A large multicenter randomized trial currently underway should provide us with some answers.

Dr. Cahill is an associate professor and chief of the division of maternal-fetal medicine in the department of obstetrics and gynecology at Washington University School of Medicine in St. Louis. She reported having no relevant financial disclosures.