Impact of Pregnancy on Mortality in Dilated Cardiomyopathy: Immediate and 12-Month Postpartum Outcomes: Data From the InCor Pregnancy and Heart Disease Registry

BACKGROUND: Pregnant women with dilated cardiomyopathy (DCM) face high risks of complications and maternal death due to hemodynamic overload, withdrawal of teratogenic but essential therapies, and limited treatment options during pregnancy. To evaluate maternal and fetal outcomes in women with DCM during pregnancy and up to 12 months postpartum, across different etiologies, and identify predictors of maternal death. METHODS: Prospective cohort of pregnant women with confirmed DCM enrolled in the InCor Pregnancy and Heart Disease Registry. All received standardized cardio-obstetric care. Left ventricular ejection fraction was assessed by echocardiography; brain natriuretic peptide was evaluated when available. Treatment during pregnancy included β-blockers, hydralazine, diuretics, nitrates, enoxaparin, and hospitalization when needed. Guideline-directed therapy was resumed postpartum. Outcomes included maternal (heart failure, arrhythmias, thromboembolism, death) and obstetric/fetal complications. Logistic regression identified predictors of maternal mortality. RESULTS: Among 983 registry patients (2013–2023), 90 had DCM. Causes were peripartum (32), idiopathic (21), myocarditis (15), Chagas disease (11), and others (11). Maternal complications occurred in 51.1% during pregnancy, 36.0% in the early postpartum period (up to 6 weeks after delivery), and 38.6% in the late postpartum period (from 6 weeks to 12 months after delivery). All 9 maternal deaths (10%) occurred postpartum—mostly due to heart failure—at a mean of 8.8±3.1 months. Cesarean section was performed in 75%, with 10% fetal loss and 33.8% prematurity. Mean birth weight was 2606 g. Left ventricular ejection fraction improved from 32% at diagnosis to 39% during pregnancy and 42% at 12 months. Lower left ventricular ejection fraction (odds ratio, 0.87; P =0.006) and prior thromboembolism (odds ratio, 15.5; P =0.017) were independent predictors of death. CONCLUSIONS: Pregnancy in women with DCM was associated with high morbidity and late mortality. Reduced left ventricular ejection fraction and a history of thromboembolism were independent predictors of maternal death.