Abstract
Objective The objective of this study was to estimate the annual rate of interhospital transfers
of pregnant and postpartum women in the United States and analyze associated patient
and health system characteristics as measures of regionalized perinatal care performance.
Methods Separate weighted univariate analyses of the 2011 Nationwide Inpatient Sample (NIS)
were performed for all maternal discharges, in-hospital deaths, and transfers. Multivariable
logistic regression analyses for transfer dispositions adjusted for health system
characteristics, maternal demographics, and diagnoses were performed. Additional perinatal
service characteristics were analyzed using NIS merged with the 2011 American Hospital
Association Annual Survey database.
Results An estimated 18,082 patients, 0.43% of maternal hospitalizations, were transferred
to an acute care hospital; 81% occurred without childbirth delivery before transfer.
Transfers were toward larger, urban teaching hospitals and hospitals with higher levels
of obstetrical and neonatal care and were more likely in states with ≥4.0 maternal–fetal
medicine specialists/10,000 live births. Blacks and Native Americans were more likely
and Hispanics and Asians were less likely than white patients to be transferred. Privately
insured women were less likely to be transferred than were others. Transfers were
associated with life-threatening maternal diagnoses and fetal indications.
Conclusion Transfers reflected a risk-based regionalized system of perinatal care, with racial
and payer differences.
Keywords
maternal interhospital transfers - Nationwide Inpatient Sample - payer - race - regionalized
perinatal care
