Balloon mitral valvotomy in pregnancy: maternal and fetal outcomes

Rheumatic mitral valve stenosis contributes to significant morbidity in pregnancy. Surgical commissurotomy has been performed during pregnancy in patients with severe mitral stenosis for several decades, but the efficacy and safety of percutaneous balloon mitral valvotomy (BMV) in this subset has not been clearly defined.

In 1996 and 1997, 40 pregnant women aged 24+/-5 years underwent BMV at 21+/-11 weeks of pregnancy. Special shielding was used during BMV to limit radiation to the fetus, except in those who were to undergo medical termination of pregnancy subsequently. A detailed echocardiographic evaluation was performed before and after BMV. After the BMV, the 29 patients in whom pregnancy was continued were assessed every 2 weeks for symptoms and fetal growth.

The BMV procedure was successful in 39 patients with an increase in mitral valve area from 0.8+/-0.2 cm2 to 1.7+/-0.2 cm2 (p < 0.001) and marked symptomatic relief. Fluoroscopy time was 7.8+/-1.9 minutes. Eleven patients whose BMV was performed before 20 weeks of pregnancy, subsequently underwent medical termination of pregnancy uneventfully. Eighteen patients had a normal delivery, three underwent cesarean section for fetal distress, one had a preterm delivery, and there was one stillbirth. Four patients are continuing pregnancy and two are lost to followup. Fullterm delivery data were available in 23 babies, whose birth weights were 2.32+/-0.5 kg. None of these babies needed any special care and were healthy at discharge.

During pregnancy, BMV by the Inoue technique is feasible, safe, and effective. There is marked symptomatic relief, along with excellent maternal and fetal outcomes.