Association of Maternal Comorbidity Burden With Cesarean Birth Rate Among Nulliparous, Term, Singleton, Vertex Pregnancies.

Importance: Cesarean birth rate among nulliparous, term, singleton, vertex (NTSV) pregnancies is a standard quality measure in obstetrical care. There are limited data on how the number and type of preexisting conditions affect mode of delivery among primigravidae, and it is also uncertain how maternal comorbidity burden differs across racial and ethnic groups and whether this helps to explain disparities in the NTSV cesarean birth rate.

Objective: To determine the association between obstetric comorbidity index (OB-CMI) score and cesarean delivery among NTSV pregnancies and to evaluate whether disparities in mode of delivery exist based on race and ethnicity group after adjusting for covariate factors.