Hospital Variation in Labor After Cesarean and Vaginal Birth After Cesarean in Massachusetts, 2012-2022.

OBJECTIVE: To examine variation in labor after cesarean and vaginal birth after cesarean (VBAC) across hospitals and to assess the role of hospital characteristics in explaining this variation. METHODS: This was a retrospective cohort study using data from the Massachusetts Pregnancy to Early Life Longitudinal Data System from 2012 to 2022; hospital characteristics were constructed with data from the Massachusetts Center for Healthcare Information and Analytics and the Neonatology Solutions NICU Directory. The sample included 80,094 births to individuals 18 years of age or older with one prior cesarean and a singleton birth at 34-42 weeks without a clear contraindication to vaginal birth. Outcomes were labor after cesarean and VBAC among those with labor after cesarean. For each outcome, we estimated three multilevel logistic regression models with a random intercept for hospital: Model 1 was an empty model without covariates; model 2 added individual characteristics; and model 3 added hospital characteristics to Model 2. RESULTS: Of 80,094 births across 47 hospitals, 31.1% had labor after cesarean, and among these, 65.2% resulted in VBAC. For labor after cesarean, the intraclass correlation coefficient was 0.239, indicating that in the empty model, 23.9% of the unexplained variation was at the hospital level. Adding individual characteristics to the model explained 2.4% of between-hospital variation, whereas adding hospital characteristics to the model explained 61.6% of between-hospital variation relative to the empty model. For VBAC among those with labor after cesarean, between-hospital variation was substantially lower than for labor after cesarean, but a large proportion of the variation was explained by adding hospital characteristics to the model. CONCLUSION: This study reveals how hospital characteristics explain a substantial share of the variation in labor after cesarean and some of the variation in VBAC. The remaining variation demonstrates differences in performance that may require understanding more about hospital unit culture and processes to fully understand; this warrants further study. Interventions targeting hospital service structure and culture may reduce barriers to labor after cesarean and promote equitable access, ultimately resulting in higher labor after cesarean and VBAC rates.