342 Quality improvement initiative to improve patient counseling using calculated vaginal birth after cesarean success likelihood

Abstract

Successful vaginal birth after cesarean (VBAC) has lower morbidity compared to a failed trial of labor after cesarean (TOLAC). The Maternal Fetal Medicine Units Antepartum VBAC Calculator uses demographics and history to predict likelihood of successful TOLAC. Prior studies have identified a threshold VBAC success probability of < 60% to result in increased risk for TOLAC-related morbidity. We implemented formal incorporation of the VBAC probability score into counseling of patients considering TOLAC, with the goal of decreasing the rate of cesarean delivery (CD) in women attempting TOLAC. At a single tertiary care center, use of an institutional “TOLAC Consult” electronic medical record smartphrase, with embedded VBAC probability calculation, was implemented in January 2019. The decision for intended mode of delivery (even with induction) was ultimately made by the patient. Prospective data were collected through April 2020 (n=321) and compared to a historical cohort dating back to January 2016 (n=693). All patients eligible for TOLAC with one or two prior CD were included. The primary process measure was high-risk induction rate, defined as percent of those with <60% probability of successful VBAC who underwent induction for TOLAC. The primary outcome measure was the rate of labored CD in this population, while the balancing measure was overall VBAC rate. Cohorts were demographically similar, though fewer in the prospective group had history of an arrest disorder (38% vs 48%, p=0.005). Among patients with VBAC probability <60%, induction rates decreased from 17% to 5% (Table 1). Labored CD rates also decreased from 15% to 10% (Figure 1), while overall VBAC rate remained unchanged from 32% to 34%. Succesful TOLAC rate improved from 68% to 77% (p=0.01). Formal incorporation of VBAC success probability into the TOLAC consultation process correlated with a decrease in induction of labor among those at elevated risk of morbidity, as well as decreased rates of labored CD, without decreasing the overall VBAC rate.View Large Image Figure ViewerDownload Hi-res image Download (PPT)