Outcomes of women with congenital heart disease admitted to acute-care hospitals for delivery in Japan: a retrospective cohort study using nationwide Japanese diagnosis procedure combination database

Background The number of women with congenital heart disease (CHD) who are of childbearing age is increasing due to advancements in medical management. Nonetheless, data on the outcomes of delivery in women with CHD remain limited. Therefore, we conducted a retrospective cohort study using a nationwide database of deliveries by women with CHD. Methods Deliveries by women with CHD discharged from acute-care hospitals between April 2017 and March 2018 were identified based on the Diagnosis Procedure Combination database which covers almost all acute-care hospitals in Japan. By using this database, we tried to include relatively high-risk deliveries by women with CHD. Subjects were divided into three groups according to the underlying disease complexity: simple, moderate, and great complexity. The clinical characteristics and incidence of peripartum cardiovascular events were compared among the three groups. Results A total of 249 deliveries from 107 hospitals were included. The largest facility had 29 deliveries per year. Given the uncertainty of underlying cardiac anomalies, 48 women were excluded, and the remaining 201 women (median age, 32 years) were analyzed. In-hospital maternal death, use of extracorporeal membrane oxygenation, intra-aortic balloon pump, pacemaker, and direct current cardioversion were not observed. Nine patients (4.5%) required intravenous diuretic administration. However, the difference in the frequency of diuretic use was not significant among the three groups (simple, 1.9%; moderate, 7.2%; great, 6.9%; P = 0.204). One participant required valve replacement surgery at 22 days after a successful cesarean section. As the disease complexity increased, deliveries occurred more frequently at university hospitals (simple, 41.7%; moderate, 52.2%; great, 72.4%; P = 0.013) and the length of hospitalization was significantly longer, with median durations of 9.0 (interquartile range [IQR] 7.0–11.0) days, 10.0 (IQR 8.0–24.0) days, and 11.0 (IQR 8.0–36.0) days in the simple, moderate, and great complexity groups, respectively (P = 0.002). Conclusions Appropriate patient selection and management by specialized tertiary institutions may contribute to positive outcomes in pregnancies in women with CHD.