The impact of obstetric unit closures on maternal and infant pregnancy outcomes.

Objective: To define the association between large-scale obstetric unit closures and relative changes in maternal and neonatal outcomes.

Data Sources/study Setting: Birth and death certificates were linked to maternal and neonatal hospital discharge records for all births between January 1, 1995 and June 30, 2005 in Philadelphia, which experienced the closure of 9 of 19 obstetric units between 1997 and 2005, and five surrounding counties and eight urban counties that did not experience a similar reduction in obstetric units.

Design: A before-and-after study design with an untreated control group compared changes in perinatal outcomes in Philadelphia to five surrounding control counties and eight urban control counties after controlling for case mix differences and secular trends (N = 3,140,782).

Results: Relative to the preclosure years, the difference in neonatal mortality (odds ratio (OR) 1.49, 95 percent CI 1.12-2.00) and all perinatal mortality (OR 1.53, 95 percent CI 1.14-2.04) increased for Philadelphia residents compared with both control groups between 1997 and 1999. After 2000, there was no statistically significant change in any outcome in Philadelphia county compared with the preclosure epoch.

Conclusions: Obstetric unit closures were initially associated with adverse changes in perinatal outcomes, but these outcomes ameliorated over time.