Maternal deaths in the United States by size of hospital.

There is growing interest in the relationship between hospital size and the comparative safety of childbearing. Using death certificates received from each state health department for 1974 to 1978 and data provided by the American Hospital Association, national maternal mortality rates were calculated by hospital size (number of inpatient beds) and size of hospital obstetric service (annual number of live births). The smallest and largest hospitals had higher rates of maternal mortality than intermediate-size hospitals. These findings may have implications for improving the safety of childbearing in the United States.