Mitral valve disease in pregnancy: outcomes and management

Young women may have asymptomatic mitral valve disease which becomes unmasked during the haemodynamic stress of pregnancy. Rheumatic mitral stenosis is the most common cardiac disease found in women during pregnancy. The typical increased volume and heart rate of pregnancy are not well tolerated in patients with more than mild stenosis. Maternal complications of atrial fibrillation and congestive heart failure can occur, and are increased in patients with poor functional class and severe pulmonary artery hypertension. Patients can be diagnosed by echocardiography and symptoms treated with beta-1 antagonists and cautious diuresis. Patients with heart failure unresponsive to treatment can undergo percutaneous balloon mitral valvuloplasty. Labour and delivery goals include reducing tachycardia by adequate pain control and minimized volume shifts. Mitral valve regurgitation, even when severe, is usually very well tolerated in pregnancy as the increase in volume is offset by a decrease in vascular resistance. On the other hand, patients with left ventricular dysfunction, moderate pulmonary hypertension or NYHA functional class III-IV are at increased risk for heart failure and arrhythmias. They may need cautious diuresis and limitations on physical activity during pregnancy, as well as invasive haemodynamic monitoring for labour and delivery. Vaginal delivery is preferred and caesarean section reserved for obstetric indications.