The association between hospital obstetric volume and perinatal outcomes in California

Abstract

Objective: We sought to analyze the association between hospital obstetric volume and perinatal outcomes in California.

Study design: This was a retrospective cohort study of births occurring in California in 2006. Hospitals were divided into 4 obstetric volume categories. Unadjusted rates of neonatal mortality and birth asphyxia were calculated for each category, overall and among term deliveries with birthweight >2500 g. Multivariable logistic regression was used to control for confounders. Deliveries in rural hospitals were analyzed separately using different volume categories.

Results: Prevalence of asphyxia increased with decreasing hospital volume overall and among term, non-low-birthweight infants, from 9/10,000 live births at highest-volume hospitals to 18/10,000 live births at the lowest-volume hospitals (P < .001). Similar trends were observed in rural hospitals, with rates increasing from 7-34/10,000 live births in low-volume rural hospitals (P < .001).

Conclusion: These findings provide evidence for an inverse association between hospital obstetric volume and birth asphyxia.