Percutaneous mitral balloon valvuloplasty (PMV) can be performed during pregnancy without significant maternal risk or fetal morbidity or mortality. However, little is known about long-term follow-up results after PMV in populations of pregnant women. Thus, the present study was undertaken to determine the immediate and long-term outcomes after PMV in a large cohort of pregnant patients with severe mitral stenosis. The patient population consisted of 71 consecutive pregnant women with severe rheumatic mitral stenosis admitted to the hospital with severe congestive heart failure (New York Heart Association class III and IV) for PMV. All patients underwent clinical and obstetric evaluations, electrocardiography, and 2-dimensional and Doppler echocardiography. PMV was successful in all patients, resulting in a significant increase in mitral valve area from 0.9 +/- 0.2 to 2.0 +/- 0.3 cm2 (p <0.001). At the end of pregnancy, 98% of the patients were in New York Heart Association functional class I or II. At a mean follow-up of 44 +/- 31 months, the total event-free survival rate was 54%. The mean gestational age at delivery time was 38 +/- 1 weeks. Preterm deliveries occurred in 9 patients (13%), including 2 twin pregnancies. The remaining 66 of 75 newborns (88%) had normal weight (mean 2.8 +/- 0.6 kg) at delivery. At long-term follow-up of 44 +/- 31 months after birth, the 66 children exhibited normal growth and development and did not show any clinical abnormalities. In conclusion, PMV is safe and effective, has a low morbidity and mortality rate for the mother and the fetus, and has favorable long-term results in pregnant women with rheumatic mitral stenosis in New York Heart Association functional class III or IV.