Trial of labor after previous single cesarean delivery in grand-multiparous women: a retrospective cohort study

Trial of labor after cesarean, vaginal birth after cesarean, and the risk of uterine rupture: an expert review

The decision to pursue a trial of labor after cesarean delivery is complex and depends on patient preference, the likelihood of successful vaginal birth after cesarean delivery, assessment of the risks vs benefits of trial of labor after cesarean delivery, and available resources to support safe trial of labor after cesarean delivery at the planned birthing center. The most feared complication of trial of labor after cesarean delivery is uterine rupture, which can have catastrophic consequences, including substantial maternal and perinatal morbidity and mortality. Although the absolute risk of uterine rupture is low, several clinical, historical, obstetrical, and intrapartum factors have been associated with increased risk. It is therefore critical for clinicians managing patients during trial of labor after cesarean delivery to be aware of these risk factors to appropriately select candidates for trial of labor after cesarean delivery and maximize the safety and benefits while minimizing the risks. Caution is advised when considering labor augmentation and induction in patients with a previous cesarean delivery. With established hospital safety protocols that dictate close maternal and fetal monitoring, avoidance of prostaglandins, and careful titration of oxytocin infusion when induction agents are needed, spontaneous and induced trial of labor after cesarean delivery are safe and should be offered to most patients with 1 previous low transverse, low vertical, or unknown uterine incision after appropriate evaluation, counseling, planning, and shared decision-making. Future research should focus on clarifying true risk factors and identifying the optimal approach to intrapartum and induction management, tools for antenatal prediction, and strategies for prevention of uterine rupture during trial of labor after cesarean delivery. A better understanding will facilitate patient counseling, support efforts to improve trial of labor after cesarean delivery and vaginal birth after cesarean delivery rates, and reduce the morbidity and mortality associated with uterine rupture during trial of labor after cesarean delivery.

VBAC calculator 2.0: Recent evidence

Following criticism for the use of race as a biological predictor of vaginal birth after cesarean (VBAC), an updated version of the Society for Maternal-Fetal Medicine (SMFM) VBAC calculator has been published. The variable "African American" or "Hispanic" (yes/no), which produced systematically lower chances of VBAC for nonwhites has been replaced with "chronic hypertension requiring treatment" (yes/no). Although there are no published external validation studies to date, developers report accuracy (area under the curve and calibration) nearly identical to the original calculator and it is published online for immediate use. This review examines the history of the calculator, measures of its validity, and recent studies measuring its performance among Hispanics, Blacks, Asians, and others with lower range scores. Underprediction of successful VBAC is evident in the original calculator, especially as predicted VBAC decreases. These studies raise a concern about the use of calculator scores in clinical management, that is, discouraging or restricting access to labor after cesarean (LAC) for parents with lower calculator scores. This raises special concern for minority populations who experience increased cesarean-related morbidity, face obstacles accessing LAC care, and who may benefit disproportionately from increased LAC uptake. Although calculator developers have discouraged using calculator scores to restrict access to LAC, such uses are documented. It is not clear what effect the removal of race will have on calculator performance, and further study is required before calculator scores are used in counseling. This includes studies that include large numbers of low scoring and minority patients.

Partogram of Grandmultiparous Parturients: A Multicenter Cohort Study

Sparse and conflicting data exist regarding the normal partogram of grand-multiparous (GMP, defined as parity of 6+) parturients. Customized partograms may potentially lower cesarean delivery rates for protraction disorders in this population. In this study, we aim to construct a normal labor curve of GMP women and compare it to the multiparous (MP, defined as parity of 2-5) partogram. We conducted a multicenter retrospective cohort analysis of deliveries between the years 2003 and 2019. Eligible parturients were the trials of labor of singletons ≥37 + 0 weeks in cephalic presentation with ≥2 documented cervical examinations during labor. Exclusion criteria were elective cesarean delivery without a trial of labor, preterm labor, major fetal anomalies, and fetal demise. GMP comprised the study group while the MP counterparts were the control group. A total of 78,292 deliveries met the inclusion criteria, comprising 10,532 GMP and 67,760 MP parturients. Our data revealed that during the first stage of labor, cervical dilation progressed at similar rates in MPs and GMPs, while head descent was a few minutes faster in GMPs compared to MPs, regardless of epidural anesthesia. The second stage of labor was faster in GMPs compared to MPs; the 95th percentile of the second stage duration of GMPs (48 min duration) was 43 min less than that of MPs (91 min duration). These findings remained similar among deliveries with and without epidural analgesia or labor induction. We conclude that GMPs' and MPs' cervical dilation progression in the active phase of labor was similar, and the second stage of labor was shorter in GMPs, regardless of epidural use. Thus, GMPs' uterus function during labor corresponds, and possibly surpasses, that of MPs. These findings indicate that health providers can use the standard partogram of the active phase of labor when caring for GMP parturients.

Barriers to labor after cesarean: A survey of United States midwives

INTRODUCTION

Despite calls for increased vaginal birth after cesarean (VBAC), <14% of candidates have VBAC. Requirements for documentation of scar type, and prohibitions on induction or augmentation of labor are not supported by evidence but may be widespread. The purpose of this study was to document midwives' perceptions of barriers to labor after cesarean (LAC) and their effects on midwives' ability to accommodate patient desires for LAC.

METHODS

Midwives certified by the American Midwifery Certification Board (AMCB) were surveyed in 2019. Multiple option and open-ended text responses were analyzed using quantitative statistics and thematic content analysis. Select barriers to LAC, ability to accommodate LAC, and supportiveness of collaborators among midwives offering LAC were explored.

RESULTS

Responses from 1398 midwives were analyzed. Eighty-four percent felt able to accommodate LAC "most of the time," and 39% reported one or more barriers to LAC. Barriers decreased ability to accommodate LAC by as much as 80%. Analysis of text responses revealed specific themes.

CONCLUSIONS

Thirty-nine percent of midwives reported their practice was limited by one or more barriers that were inconsistent with professional guidelines. Imposition of barriers was driven primarily by collaborating physicians, and superceded supportive practices of midwives, nurses, and system administrators. Affected midwives were significantly less able to accommodate patient requests for LAC than those not affected. Midwives also reported pride in providing VBAC care, restrictions specific to midwifery scope of practice, and variation in physician support for LAC within practices affecting their ability to provide care.