Pregnancy in cardiac patients: possible influence of volume overload by pregnancy on pulmonary circulation.

To evaluate the influence of volume overload by pregnancy on heart diseases, the relations between cardiac status before pregnancy and clinical courses during pregnancy were studied, especially from the viewpoint of pulmonary circulation. In 206 pregnant cardiac patients whose prepregnancy laboratory data were known, the deterioration (appearance or advance of heart failure) during pregnancy was prospectively related to: pulmonary congestion (p less than 0.05), enlarged left atrium (p less than 0.05), atrial fibrillation (p less than 0.01) and right ventricular hypertrophy (p less than 0.005) in mitral stenosis; cardiomegaly (p less than 0.05) and atrial fibrillation (p less than 0.005) in mitral regurgitation; cardiomegaly (p less than 0.005) in congenital heart diseases; and to previous congestive heart failure (p less than 0.005) in total cases. All of the cases with systolic pulmonary artery pressure higher than 50 mmHg deteriorated during pregnancy. Some cases with no deteriorating laboratory findings showed dyspnea suddenly at the end of pregnancy. In 1033 cardiac patients who had experienced pregnancy, deterioration during pregnancy was seen more frequently in cases with mitral valvular diseases that in those with aortic valvular diseases. No deterioration was seen in pulmonary stenosis patients. Abnormal status of pulmonary circulation may be one of the important determining factors of deterioration by pregnancy in cardiac patients. The criteria for permitting pregnancy in cardiac patients are proposed.