The second stage of labor is defined as the time from complete dilation to delivery of the infant. Modifiers that affect the second stage length include factors such as parity, epidural anesthesia, delayed pushing, fetal station at complete dilation, maternal body mass index, fetal weight and occiput posterior (OP) position. Optimization of the second stage of labor is essential to ensure safe maternal and fetal outcomes.
In the United States, cesarean section rates are on the rise. The most common indication for cesarean section is labor arrest, accounting for 34% of all primary cesarean deliveries. Active management of labor throughout the first and second stage can help early identification of problems to guide practitioners in adjusting modifiable factors.
The Healthy People project, by the Department of Health and Human Services, identified a goal national cesarean section rate of 23.9% for nulliparous term singleton vertex (NTSV) patients by 2020. Currently at UWMC the NTSV rate is 39.4%, and for UW Medicine is 28.3%. Reviewing UWMC data, most of the NTSV cesarean sections occur either after spontaneous or induced labor, implying that most are not scheduled primary cesarean sections. The most common reason for cesarean section at UWMC is failure to progress or failure of descent. When reviewing compliance with the current second stage management duration guidelines as determined by ACOG, SMFM and NICHD, UWMC is 100% at goal for time allowance prior to cesarean section. Thus, we are not moving towards cesarean delivery too early without giving the patient adequate time to progress to vaginal birth. At the same time, the UWMC rate of severe neonatal morbidity is 1%, which is below the state average of 1.4%.
Within UW Medicine, we hope to optimize second stage management and thereby improve overall vaginal delivery rates without increasing adverse maternal or neonatal outcomes. In this document we will establish University of Washington guidelines regarding the following 4 second stage of labor issues: 1) length of second stage, 2) delayed pushing, 3) rotational maneuvers, and 4) optimal pushing techniques. Beyond the scope of this discussion are operative vaginal deliveries (OVD), rotational forceps, episiotomy, regional anesthesia and nursing maneuvers such as changing maternal position to facilitate descent.