775 Racial and ethnic disparities in rates and success of trial of labor after cesarean

Abstract

The Maternal-Fetal Medicine Units Network vaginal birth after cesarean (VBAC) calculator is widely used to predict success of trial of labor after cesarean (TOLAC). Predictor variables include race and ethnicity, raising concerns that this calculator is widening disparities in cesarean section rates. Our aim was to assess racial and ethnic disparities in rates of TOLAC. This is a population-based retrospective cohort study using National Center for Health Statistics live birth data between 2014 and 2018. Women who delivered a cephalic, singleton gestation, ≥ 37 weeks with a history of one prior cesarean section were included. TOLAC rates were calculated by race/ethnicity and stratified by insurance status. The primary outcome was rate of TOLAC by race/ethnicity. The secondary outcome was rate of VBAC among groups. Multivariate logistic regression was performed to adjust for BMI, maternal age, prior vaginal delivery and insurance status. 1,481,898 women met inclusion criteria; 57.3% Non-Hispanic White (NHW), 16.0% Non-Hispanic Black (NHB), 26.6% Hispanic. TOLAC rates were highest in NHB women (26.5% versus NHW 22.5% and Hispanic 23.1%; p<.001). Medicaid patients had higher rates of TOLAC compared to privately insured patients 23.5% vs 21.7% (p<0.001). For NHW women with Medicaid, rate of TOLAC was 20.9% vs 22.1% for private insurance (p<0.001), compared to NHB women 27.9% vs 22.5% (p<0.001), and Hispanic women (23.5% vs 19.8%, p<0.001). After adjustment, odds of TOLAC were similar in NHB (OR 1.01 95% CI 0.99-1.03), but lower in Hispanic women (OR 0.87 95% CI 0.85 – 0.88) compared to NHW women. Successful VBAC was significantly lower among NHB (OR 0.54 95% CI 0.52 – 0.56) and Hispanic (OR 0.84 95% CI 0.81-0.88) women compared to NHW women. Despite similar TOLAC rates between NHB and NHW women, VBAC is significantly lower in NHB women. Hispanic women have lower TOLAC and VBAC rates than NHW women. Race/ethnicity and tools that include this predictor may influence management of TOLAC and contribute to the disparity in cesarean section rate.