Trends in racial and ethnic disparity for the risk of primary cesarean delivery

The primary cesarean delivery rate has significantly increased over time leading to important impacts on maternal morbidity and mortality. Racial disparities in obstetric care have been well well-established, and may impact primary cesarean delivery rates. The aim of this study is to describe trends in rates and indications for primary cesarean delivery by race and ethnicity. This is a retrospective cohort study of term, vertex, non-anomalous, singleton pregnancies without a previa or history of a prior cesarean between 2004-2019. Study years were grouped by four-year epochs. The Cochran-Armitage test for trend was used to assess for differences in primary cesarean delivery rates and indications over time stratified by race and ethnicity. Logistic regression was used to generate crude and adjusted Odds Ratios (OR) and 95% confidence intervals (CI) adjusting for confounders. There were 21,784 women included in the analysis. The overall primary cesarean delivery rate increased over the study period (14.8% vs 17.7%, p< 0.001). Patients who underwent primary cesarean delivery were more likely older, with higher body mass index, and with underlying medical comorbidities. There was an increased trend in primary cesarean delivery in nulliparous NH-Black women (25.3% vs 35.8%, p< .001). This trend was not seen for multiparous NH-Black women or NH-White or Hispanic women regardless of parity (Figure 1). With unadjusted data, nulliparous NH-Black women were more likely to undergo cesarean delivery (OR 1.64, CI 1.35-2.01). However, after adjustment this was not significant (aOR 0.75, CI 0.30-1.85). Arrest disorders were the most common indication for cesarean overall (53.0%), with higher odds for nulliparous NH-black women (aOR 3.67, CI 1.19-11.38). There is a significant increasing trend in primary cesarean delivery in nulliparous NH-black women over time, but not in Hispanic, NH-White, or multiparous women. Increasing medical complexity in this population may contribute to these findings. Optimization of medical conditions before and during pregnancy may improve outcomes.