Foundational to the midwifery paradigm is that normal physiologic birth has the potential to enhance healthy outcomes for mothers and infants.1 Induction or augmentation of labor with oxytocin is a disruption in the process of normal physiologic birth.1 Therefore, it is not surprising that elective induction of labor fuels the debate over how birth is approached philosophically in medicine and midwifery.1,2 In particular, the recent "A Randomized Trial of Induction Versus Expectant Management (ARRIVE)" raises questions on the costs of increased medicalization of birth, staffing, hospital capacity, and shared decision-making.1,2 To better understand the ARRIVE trial results and potential lessons, this column summarizes the study results, key resources in decreasing cesarean birth rates when decision to induce is made, and implications for person- and family-centered decision-making. If induction of labor is elected or indicated, the question is "What are the best practice guidelines to promote vaginal delivery?"
SUMMARY OF THE ARRIVE TRIAL
The ARRIVE trial was designed to determine whether elective induction of labor during the 39th week of pregnancy would lower the morbidity and mortality rates of infants compared with waiting until at least 40 weeks and 5 days for elective induction.2 In addition, the researchers wanted to compare the effect of induction versus expectant management on cesarean birth rates. The study was conducted by the National Institute of Child Health and Human Development's Maternal Fetal Medicine Units Network and took place at 41 hospitals.2
Eligibility criteria included nulliparous, term, singleton, vertex (NTSV) with no major medical complications. Participants were randomly assigned to induction or expectant management and included 3000 women in each arm. Main results included that delivery in the induction of labor group was significantly earlier than that in the expectant management group (39.3 weeks vs 40.0 weeks). Preeclampsia and gestational hypertension occurred in 9% of the induction group versus 14% of the expectant management group. The frequency of cesarean delivery was lower in the induction of labor group (18.6% vs 22.2%; RR = 0.84; 95% CI, 0.76-0.93).2 Key to the significant difference in cesarean birth rates is in the guidelines utilized in the induction group.
CONTEMPORARY LABOR CURVES AND INDUCTION OF LABOR
The consortium on safe labor highlighted important data on length of labor, particularly in the latent phase, and that the progress of time from 4 to 6 cm is slower than what is historically described.3 Utilizing this more contemporary understanding of the labor curve, the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine issued a joint Obstetric Care Consensus in March 2014 using updated guidance on labor management with the goal of safely lowering the rate of cesarean birth.4 Concurrently, the American College of Nurse-Midwives developed and published the online resource BirthTools,5 with resources and bundles to promote vaginal birth. The first recommendation by all groups is that a prolonged latent phase is not an indication for cesarean birth.3,5 In the setting of induction of labor, the latent phase is even longer, requiring cervical ripening methods prior to initiation of Pitocin.3
Active labor typically begins at 6 cm, rather than 4 cm as previously thought, and standards for active labor should not be applied prior to 6 cm.3 In addition, a slow, but progressive, labor in the first stage is not an indication for cesarean birth.3
PROMOTION OF PROGRESS
Evaluation of labor progress includes the assessment of uterine power, the effects of ambulation, hydration, temperature, artificial rupture of membranes, the use of an intrauterine pressure catheter, and amount of Pitocin.5 Assessment of the fetal weight, position and attention to maternal positioning, bladder status, and coping are included.5
Guidelines for active-phase arrest in the first stage of labor are reserved for women at or beyond 6 cm dilated with ruptured membranes who fail to progress despite 4 hours of adequate uterine activity or at least 6 hours of oxytocin administration with inadequate uterine activity and no cervical change.3 A second-stage arrest may be considered after 3 hours of pushing in a nulliparous person with little progress.3 Manual rotation of the fetal occiput in the setting of fetal malposition in the second stage and operative vaginal delivery are reasonable interventions to consider prior to a decision for cesarean birth.3
THE DIAGNOSIS OF FAILED INDUCTION
Current guidance from the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine recommends that as long as maternal and fetal status is reassuring, cesarean births for failed induction of labor in the latent phase can be avoided by allowing longer durations of the latent phase (up to 24 hours or longer) and requiring that oxytocin be administered for at least 12 to 18 hours after membrane rupture before decision for cesarean birth is warranted. The vast majority of women undergoing induction of labor will enter active labor at 15 hours following rupture of membranes and Pitocin titration.3,6
The California Maternal Quality Care Collaborative has developed evidence-based, objective checklists on both dystocia and failed induction. These checklists aim to reduce the primary cesarean birth rate by preventing premature cesarean delivery for indications of labor dystocia.7
TRANSPARENCY AND SHARED DECISION-MAKING
Ariadne Labs is currently testing the utility of "whiteboards" in labor rooms.8 The purpose is to identify patient preferences and improve team communication. This can be enhanced further by using contemporary labor curves on the board, making labor progress transparent-for provider, labor nurse, mother, and support persons. Utilization of a partograph on the whiteboard visible to the patient and her support team allows for open, clear dialogue regarding labor progress and guidelines for cesarean birth.
In 2020, The Joint Commission will require public reporting of hospital NTSV cesarean birth rates.3 Many hospitals have turned to internal, but open, reporting of cesarean birth rates between practices and individuals. Cesarean huddles, audit committees, and reviews for unplanned cesarean birth are being incorporated into team-based care.
CONCLUSION
The ARRIVE trial gives critical information for providers and persons deciding on induction and guidelines that promote vaginal delivery in the setting of induction of labor. Nonintervention in the latent phase when the maternal and fetal conditions permit and accurate determination of active phase are paramount. Following the guidance from the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine on diagnosis of failed induction in addition to patience, transparency, and shared decision-making along the path it is recommended to incorporate resources available in BirthTools.
-Elisabeth D. Howard, PhD, CNM, FACNM
Director of Midwifery
Women and Infants Hospital
Associate Professor
Obstetrics and Gynecology (Clinical)
Alpert Medical School of Brown University
Providence, Rhode Island
References