Four million women give birth each year in the United States. While the reported incidence of maternal pregnancy-related mortality is low (14.5 per 100,000 live births), the rate of obstetric complications is nearly 13 percent. Laurent Glance of the University of Rochester and coauthors analyzed data for 750,000 obstetrical deliveries in 2010 from the Healthcare Cost and Utilization's Nationwide Inpatient Sample.

They found that women delivering vaginally at low-performing hospitals had twice the rate of any major complications (22.55 percent) compared to vaginal deliveries at high-performing hospitals (10.42 percent). For cesarean deliveries, the difference was even more pronounced: Women undergoing C-sections at low-performing hospitals were nearly five times more likely to experience a major complication than women at a high-performing hospital: 20.93 percent versus 4.37 percent. (Hospitals were classified as having low, average, or high performance based on a calculation of the relative risk that a patient would experience a major complication.)

The authors conclude that narrowing the quality gap in obstetrical care could lead to improved outcomes for large numbers of women.

Study: Rates Of Major Obstetrical Complications Vary Almost Fivefold Among US Hospitals, Laurent G. Glance, Andrew W. Dick, J. Christopher Glantz, Richard N. Wissler, Feng Qian, Bridget M. Marroquin, Dana B. Mukamel and Arthur L. Kellermann, Health Affairs, doi: 10.1377/hlthaff.2013.1359, published August 2014.