Pregnancy is increasingly common in women with congenital heart disease (CHD), but little is known about long-term cardiovascular outcome after pregnancy in these patients. We studied the incidence of cardiovascular events 1-year postpartum and compared cardiac function prepregnancy and 1-year postpartum in women with CHD.

From our national, prospective multicenter cohort study, 172 women were studied. Follow-up with clinical evaluation and echocardiography and NT-proBNP measurement were performed during pregnancy and 12 months postpartum. Cardiovascular events were defined as need for an urgent invasive cardiovascular procedure, heart failure, arrhythmia, thromboembolic events, myocardial infarction, cardiac arrest, cardiac death, endocarditis, and aortic dissection.

Cardiovascular events were observed after 11 pregnancies (6.4%). Women with cardiovascular events postpartum had significant higher NT-proBNP values at 20-week gestation (191 [137-288] vs 102.5 [57-167]; P = .049) and 1-year postpartum compared with women without cardiovascular events postpartum (306 [129-592] vs 105 [54-187] pg/mL; P = .014). Women with cardiovascular events during pregnancy were at higher risk for late cardiovascular events (HR 7.1; 95% CI 2.0-25.3; P = .003). In women with cardiovascular events during pregnancy, subpulmonary end-diastolic diameter had significantly increased 1-year postpartum (39.0 [36.0-48.0] to 44.0 [40.0-50.0]; P = .028). No other significant differences were found in cardiac function or size 1-year postpartum compared with preconception values.

Cardiovascular events are relatively rare 1 year after pregnancy in women with CHD. Women with cardiovascular events during pregnancy are prone to develop cardiovascular events 1-year postpartum and have increased subpulmonary ventricular diameter compared with preconception values.