RESUMO
Valvular heart disease constitutes the majority of all causes of heart disease in pregnancy. In the presence of valvular heart disease, the necessary haemodynamic changes of pregnancy might cause heart failure, leading to severe maternal and fetal morbidity and even mortality. In lower-income countries, rheumatic heart disease remains one of the major causes of death related to pregnancy [6]. In low-income countries, rheumatic heart disease is found in 60% to 80% of the pregnant women with heart disease, and 10% to 30% have a congenital disorder including congenital valve disorders [4]. The most common valvular lesion of rheumatic heart disease is mitral stenosis. This valvular lesion can be the cause of extreme disability and even mortality during pregnancy due to an increase in the transvalvular gradient and a rise in left atrial pressure. The maternal mortality associated with mitral stenosis is stratified by New York Heart Association (NYHA) classification: class I, 0.1%; class II, 0.3%; class III, 5.5%; and class IV, 6.0%. Most patients are in class I or II at presentation, but 12% to 25% of patients are in class III or IV [14].