Hospital case volume and maternal adverse events following abnormal deliveries: Analysis using a Japanese national in-patient database.

Abstract

To clarify the relationship between the number of deliveries and maternal outcomes in Japan, considering the declining birth rate and the evidence that hospitals with few deliveries have medical safety issues. Hospitalizations for deliveries were analyzed using the Diagnosis Procedure Combination database from April 2014 to March 2019, after which maternal comorbidities, maternal end-organ injury, medical treatment during hospitalization, and hemorrhage volume during delivery were compared. Hospitals were divided into four groups based on the number of deliveries per month. A total of 792 379 women were included in the analysis, among whom 35 152 (4.4%) received blood transfusions, with a median blood loss of 1450 mL during delivery. Regarding complications, pulmonary embolism was significantly more frequent in hospitals with the lowest number of deliveries. Using a Japanese administrative database, this study suggests an association between hospital case volume and the occurrence of preventable complications, such as pulmonary embolisms.