Photo Credit: Aziz Karimov

The removal of race and ethnicity from a vaginal birth after cesarean calculator did not impact labor or VBAC rates among certain racial and ethnic groups.

Removing race and ethnicity from the Maternal-Fetal Medicine Units Network’s vaginal birth after cesarean (VBAC) calculator did not change rates of trial of labor after cesarean (TOLAC) or VBAC among racial or ethnic groups, according to findings published in Obstetrics & Gynecology.

“In the original version, African American or Hispanic identity reduced the probability of successful VBAC,” Katherine Ahrens, PhD, and colleagues wrote. “Due to concern that this systematized medical racism and perpetuated racial inequities, a revised calculator without race and ethnicity was published in 2021.”

The researchers investigated whether the revision affected TOLAC and VBAC rates by race and ethnic group in a population-based cohort study that analyzed US natality data between 2019 and 2022. Among 1.6 million people included in analysis, groups with the largest number of births were included, spanning 403,565 Hispanic individuals, 103,465 non-Hispanic Asian individuals, 234,505 non-Hispanic Black individuals, and 767,593 non-Hispanic White individuals.

For the entire study period, the average TOLAC rate was 22.0 per 100 deliveries, which ranged from 21.2 among Hispanic and non-Hispanic White individuals to 24.9 among non-Hispanic Black individuals. The average VBAC rate was 16.4 per 100 deliveries and ranged from 15.8 among Hispanic individuals to 16.7 among non-Hispanic Black individuals.

VBAC Remains Low for Black, Asian, & Hispanic Patients

After the calculator change, TOLAC and VBAC rates were unchanged, Dr. Ahrens and colleagues found.

Both before and after the calculator revision, successful VBAC rates were lower for non-Hispanic Asian (71.1% before and 71.0% after), non-Hispanic Black (67.3% and 67.0%), and Hispanic (74.3% and 75.0%) people compared with non-Hispanic White (78.3% vs 77.2%) people, according to the study.

“Consistent with previous reports, despite having the highest rates of TOLAC, non-Hispanic Black individuals had the lowest rate of successful VBAC, followed by non-Hispanic Asian and Hispanic individuals,” the researchers observed.

Because its creation was based on observational data, even the revised VBAC calculator reflects the cumulative influence of systems as well as behaviors on TOLAC outcomes, the authors noted. Body mass index and hypertension, for example, are influenced by structural racism yet remain in the calculator because of associations with lower rates of successful VBAC.

“Altogether, it is unsurprising that racial disparities persist despite the calculator change; more work is clearly needed to achieve equity in TOLAC outcomes,” Dr. Ahrens and colleagues wrote.