(1003) Racial disparities in cesarean deliveries without trial of labor: a population-based analysis of birth timing

Objective: While racial disparities in obstetrics are multifactorial, differences in resource allocation may contribute to the disparity. Here, we assess racial differences in delivery timing for cesarean deliveries (CD) without a trial of labor (TOL).

Study Design: This retrospective population-based cohort used birth certificate data from the National Vital Statistics System from 2016-2021, which includes birth timing for CD in the US. Since the timing of planned CD may be more susceptible to external systemic influences, this analysis focuses on CD without TOL. We excluded CD with TOL and unknown delivery time. Maternal race was self-identified (White, Black, Asian, American Indian or Alaskan Native, Native Hawaiian or Pacific Islander, or mixed or other race) and categorized as White or Black, Indigenous, and People of Color (BIPOC). The number of CD without TOL at each minute was normalized relative to totals in each racial group to allow for balanced comparison. The cumulative sum in the proportion of CD was calculated starting from 6:00 a.m. Differences in cumulative sum of CD between races were analyzed with the Kolmogorov-Smirnov test.

Results: Among 7,045,802 patients who underwent a CD without TOL, 72% were categorized as White and 26.3% as BIPOC; less than 3% had unknown racial data. For both groups, the highest proportion of CD occurred around 8:00 a.m. followed by a second peak around 12:30 p.m. Differences in the cumulative sum distribution exist between racial groups (p=0.01). The largest difference in the cumulative sum distribution between groups is observed at 10:10 a.m. between White and BIPOC patients; by this time, CD without TOL occurred for 35% of White patients versus only 28% of BIPOC patients.

Conclusion: This population-based study reveals differences in the timing of CD without TOL between White and BIPOC patients, with White patients more likely to undergo CD earlier in the clinical workday. Future research should assess root causes, and whether disparities in resource allocation contribute to differences in obstetrical outcomes.