Racial and Ethnic Differences in Labor Duration and Cesarean Indications Among Low-Risk Nulliparous Term Singleton Vertex Births: A Retrospective Analysis

Background/Objectives: Racial and ethnic disparities in cesarean birth and labor management persist in the United States, including among individuals considered low risk. Understanding variation in labor progression and cesarean indications within low-risk nulliparous, term, singleton, vertex (NTSV) births may help clarify potential contributors to inequities. This study examined differences in cesarean rates, cesarean indications, and labor duration by race and ethnicity in a low-risk NTSV cohort. Methods: We conducted a retrospective secondary analysis of electronic medical record data from 13,231 low-risk NTSV births within a Midwestern academic health system. Multivariable logistic regression models were used to evaluate the likelihood of cesarean birth and cesarean indications by race and ethnicity, adjusting for maternal age, gestational age, body mass index, insurance type, and labor onset. Linear regression models examined differences in first-stage, second-stage, and total labor duration. Interaction terms assessed whether associations varied by labor onset. Results: The overall cesarean rate was 29%. Absolute cesarean rates were higher among non-Hispanic Black and Hispanic individuals compared with non-Hispanic White individuals; however, these differences were not statistically significant after adjustment. Labor duration differed significantly by race and ethnicity. Non-Hispanic Black and Hispanic individuals experienced longer median first-stage and total labor durations compared with non-Hispanic White individuals; however, second-stage duration was markedly shorter among non-Hispanic Black individuals. Among induced labors resulting in cesarean birth, non-Hispanic Black and Hispanic individuals had increased odds of cesarean for early arrest of dilation, although these findings should be interpreted as hypothesis-generating, given data limitations in labor onset documentation. Body mass index was positively associated with likelihood of cesarean. Conclusions: In this low-risk NTSV cohort, adjusted cesarean rates did not differ significantly by race or ethnicity; however, differences in labor duration and cesarean indication were observed. These findings underscore the importance of continued investigation into labor management practices and structural contributors to obstetric inequities.