Birth Hospitalization Costs and Days of Care for Mothers and Neonates in California, 2009-2011.

OBJECTIVE: To provide population-based estimates of the hospital-related costs of maternal and newborn care, and how these vary by gestational age and birth weight.

STUDY DESIGN: We conducted a retrospective analysis of 2009-2011 California in-hospital deliveries at nonfederal hospitals with the infant and maternal discharge data successfully (96%) linked to birth certificates. Cost-to-charge ratios were used to estimate costs from charges. Physician hospital payments were estimated by mean diagnosis related group-specific reimbursement and costs were adjusted for inflation to December 2017 values. After exclusions for incomplete or missing data, the final sample was 1 265 212.

RESULTS: The mean maternal costs for all in-hospital deliveries was $8204, increasing to $13 154 for late preterm (32-36 weeks) and $22 702 for very preterm (<32 weeks) mothers. The mean cost for all newborns was $6389: $2433 for term infants, $22 102 for late preterm, $223 931 for very preterm infants, and $317 982 for extremely preterm infants (<28 weeks). Preterm infants were 8.1% of cases but incurred 60.9% of costs; for very preterm and extremely preterm infants, these shares were 1.0% and 36.5%, and 0.4% and 20.0%, respectively. Overall, mothers incurred 56% of the total costs during the delivery hospitalization.

CONCLUSIONS: Both maternal and neonatal costs are skewed, with this being much more pronounced for infants. Preterm birth is much more expensive than term delivery, with the additional costs predominately incurred by the infants. The small share of infants who require extensive stays in neonatal intensive care incur a large share of neonatal costs and these costs have increased over time.