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Health Equity/Community Health

Poster Session 3

(646) Unintended consequences of inclusion of race in the TOLAC calculator, a birth certificate data study

Wednesday, February 14, 2024
8:30 AM – 10:00 AM  
Location: Prince George's Exhibit Hall CDE, Lower Atrium Level
Foundation Awardee
Objective: In 2007, the Maternal Fetal Medicine Units Network published a widely available trial of labor after cesarean (TOLAC) calculator that included race as a data point. In 2021, the calculator was then revised to remove race from the calculator. The objective of this project was to determine if inclusion of race in the calculator changed TOLAC and vaginal birth after cesarean (VBAC) rates nationwide.

Study Design:

We conducted a retrospective study using data extracted from the Vital Statistics Natality Birth Data. Individuals were included if they delivered between 2003-2007 (the "early" group) or 2014-2019 (the "late" group), had a prior cesarean delivery, and were cephalic at the time of presentation. Patients delivering between 2008-2013 were excluded to allow for a washout period. Patients were also excluded if their TOLAC status was unknown. Three categories of race were analyzed: non-Hispanic White, Hispanic, and non-Hispanic Black. Statistical analysis was conducted using a Poisson regression and post-hoc testing with estimated marginal means in R.

Results:

2,134,498 births met criteria during the two study periods, 22% of whom were in the early group and 78% were in the late group. Rates of TOLAC increased in all three groups, though the effect size was largest in the Hispanic population (P=0.01). Although intrapartum cesarean rates were not significantly different between race categories in the early group, Black patients were more likely to undergo intrapartum cesareans compared to White patients in the late group (p< 0.01). Likewise,  Hispanic patients were more likely to undergo intrapartum cesareans in the late group (p=0.01). Figure 1 demonstrates the trend in intended and actual mode of delivery over time.

Conclusion:

Nationally, intrapartum cesarean rates for Black and Hispanic patients significantly increased after original TOLAC calculator was released without increasing the rates of planned cesarean deliveries or changing the intrapartum cesarean rates in White patients. These findings highlight new, unintended bias associated with tools intended to enhanced clinical decision-making.