Spontaneous vaginal birth varies significantly across US hospitals

Birth is the most common reason for hospitalization in the United States. Hospital variation in maternal outcomes is an important indicator of health care quality. Spontaneous vaginal birth (SVB) is the most optimal birth outcome for the majority of mothers and newborns. The purpose of this study was to examine hospital-level variation in SVB overall and among low-risk women in a four-state sample representing 25% of births in the United States in 2016.

Women giving birth in California, Pennsylvania, New Jersey, and Florida were identified in 2016 state discharge abstracts. Patient data were merged with hospital data from the American Hospital Association's (AHA) 2016 Annual Survey. Overall and low-risk SVB rates were calculated for each hospital in the sample and stratified by bed size, teaching status, rurality, birth volume, and state.

Our final sample included 869 681 women who gave birth in 494 hospitals. The mean overall SVB rate in the sample was 61.1%, ranging from 16.8% to 79.9%. The mean low-risk SVB rate was 78% and ranged from 34.6% to 93.3%. Variation in SVB rates cut across all the hospital structural characteristic strata.

The wide variation in SVB rates indicates significant room for improvement in this maternal quality metric. Our finding, that hospitals of all types and locations had both low and high SVB rates, suggests that excellent maternal outcomes are possible in all hospital settings. The variation in SVB rates across hospitals warrants research into modifiable hospital factors that may be influencing SVB rates.