1086: Retrospective application of the clark algorithm to cesarean sections for fetal intolerance to labor

Abstract

Abnormal fetal heart rate tracings account for a significant number of cesarean sections (23% in 2016). Clark, et al. developed an algorithm for management of category II fetal heart rate tracings in labor (figure 1). We aim to determine the extent of compliance and noncompliance of fetal monitoring with the Clark algorithm and if differences lead to disparate neonatal outcomes. This is a retrospective observational study from the resident service at an academic-community tertiary care center from 2013-2018. We reviewed archived fetal heart rate tracings from patients with cesarean section (CS) performed for fetal intolerance to labor (FIL) and interpreted tracings against the algorithm. We assigned tracings to one of three categories: Group 1—compliant; Group 2—noncompliant too early (algorithm permits the patient to labor longer); Group 3—noncompliant too late (algorithm suggests performing the CS sooner). Maternal demographics, features of labor, and neonatal outcomes were compared among the compliant and noncompliant groups. Of the 110 cases, 27 (24.5%) had a CS called in group 1, 49 (44.5%) in group 2, and 34 (30.9%) in group 3. Baseline characteristics were similar. Of the 49 in group 2, 46 (93.9%) violated the algorithm at the same branchpoint (#6, figure 1). In group 3, cesarean sections would have been performed on average 244 minutes earlier had the algorithm been used. Neonatal outcomes were not significantly different among the groups (table 1), including 5-minute Apgar < 7 (2/27 for group 1, 2/49 for group 2, 1/34 for group 3; p=0.71), pH < 7.1 (3/27 for group 1, 4/49 for group 2, 5/34 for group 3; p=0.69), and NICU admit (13/27 for group 1, 26/49 for group 2, 17/34 for group 3; p=0.88). Our retrospective application of the algorithm showed that 44.5% of patients who have CS for FIL may be able to labor longer and that violation at a common decision point on the algorithm is responsible for nearly all such CS. More studies are needed to evaluate if CS rates for FIL can be reduced without impacting neonatal outcomes using the algorithm.View Large Image Figure ViewerDownload Hi-res image Download (PPT)