This report analyses the efficacy and tolerance of percutaneous mitral
commissurotomy (PMC) in 10 pregnant women with severe mitral stenosis
. Pregnancy was the cause of decompensation of the mitral stenosis and
surgery was not considered because of the foetal risk. PMC was undert
aken after an average of 26 +/- 4 weeks of gestation (range 23-33 week
s). The average age of the patients was 28 +/- 6 years (range 20-41 ye
ars). Six patients were in NYHA Class III and 4 in Class IV despite me
dical treatment. Five patients had mild mitral regurgitation. Foetal p
rotection was ensured by covering the mother's abdomen with a lead apr
on. The double balloon technique was used in 4 cases and Inoue's ballo
on in 6 patients. The average duration of fluoroscopy was 17 +/- 10 mi
nutes (range 6-37 minutes). After PMC, the mean pulmonary artery press
ure decreased from 47 +/- 12 mmHg to 31 +/- 11 mmHg (p = 0.005); two d
imensional echocardiography showed an increase in mitral valve surface
area from 1 +/- 0.2 cm2 to 2 +/- 0.3 cm2 (p = 0.005). There were no c
omplications related to the procedure. The foetal heart rate was monit
ored continuously and no significant modification suggestive of foetal
distress was recorded. The abdominal cutaneous dose of irradiation wa
s less than 0.2 millisievert, which was minimal. All patients experien
ced a functional improvement after PMC. Nine delivered after an averag
e gestation of 38 +/- 2 weeks (range 36-42 weeks) without cardiac deco
mpensation. The average birth weight of the babies was 3.1 +/- 0.3 kg
(range 2.9-3.7 kg). One neonatal death occurred 3 months after PMC aft
er a caesarian section performed at 29 weeks of gestation for obstetri
cal reasons. These results show that PMC is effective and well tolerat
ed and may be offered to pregnant women who remain symptomatic despite
medical treatment.