Postpartum readmissions among patients with adult congenital heart disease.

Background: Given the risks associated with congenital heart disease in the postpartum period, epidemiologic data identifying risk factors and timing of complications may be useful in improving postpartum care.

Objective: This study aimed to determine the timing of, risk factors for, and complications associated with 60-day postpartum readmissions following deliveries with maternal congenital heart disease.

Study Design: The 2010-2020 Nationwide Readmissions Database was used for this retrospective cohort study. Postpartum readmissions occurring within 60 days of delivery hospitalization discharge were ascertained. Clinical, demographic, and hospital risk factors associated with postpartum readmission were analyzed using logistic regression models, with unadjusted and adjusted odds ratios as measures of association. Among patients with congenital heart disease, the role of additional cardiac risk factors in the likelihood of readmission was analyzed. Risks for adverse maternal outcomes during readmission were analyzed, including severe maternal morbidity, cardiac severe maternal morbidity, and a critical care composite.

Results: Of an estimated 40,780,439 delivery hospitalizations, 35,242 had an associated congenital heart disease diagnosis (8.6 per 10,000), including 2279 (6.5%) with complex congenital heart disease and 32,963 (93.5%) with noncomplex congenital heart disease. The proportion of deliveries with a maternal congenital heart disease diagnosis increased significantly from 6.7 per 10,000 in 2010 to 11.8 in 2020. Overall risk for 60-day postpartum readmission was 1.6% among women without congenital heart disease and 3.1% among women with congenital heart disease (P<.01). Among women with congenital heart disease, 36.0% of 60-day postpartum readmissions occurred 1 to 5 days after discharge, 18.0% 5 to 10 days after discharge, and 14.5% 10 to 20 days after discharge. In adjusted models for the entire population, congenital heart disease retained a significant association with 60-day postpartum readmission (adjusted odds ratio, 1.73; 95% confidence interval, 1.55-1.94). When the cohort was restricted to deliveries with congenital heart disease, adjusted analyses demonstrated increased odds associated with additional cardiac risk factors (congestive heart failure: adjusted odds ratio, 1.72; 95% confidence interval, 1.13-2.62; arrhythmia: adjusted odds ratio, 1.68; 95% confidence interval, 1.27-2.21; pulmonary circulation disorders: adjusted odds ratio, 1.57; 95% confidence interval, 1.10-2.24; and chronic hypertension: adjusted odds ratio, 1.88; 95% confidence interval, 1.26-2.80), hypertensive disorders of pregnancy (adjusted odds ratio, 1.97; 95% confidence interval, 1.49-2.61), and cesarean delivery (primary adjusted odds ratio, 1.82; 95% confidence interval, 1.39-2.38; repeat cesarean: adjusted odds ratio, 1.91; 95% confidence interval, 1.42-2.55). The risk of adverse outcomes during readmissions was higher for women with congenital heart disease than for those without (severe maternal morbidity: 23.8% vs 16.1%; P<.01; cardiac severe maternal morbidity: 9.6% vs 4.9%; P<.01; and a critical care composite: 3.1% vs 1.8%; P<.01).

Conclusion: Deliveries with congenital heart disease were associated with increased odds of postpartum readmission and complications during readmissions. Most readmissions occurred soon after delivery discharge. Among patients with congenital heart disease, risk for readmission was higher in the setting of additional cardiac risk factors, hypertensive disorders of pregnancy, and cesarean delivery.