Mitral stenosis in pregnancy: a four-year experience at King Edward VIII Hospital, Durban, South Africa

Objective To evaluate prospectively mitral stenosis in pregnancy with emphasis on women with persistent symptoms. Setting King Edward VIII Hospital, a tertiary referral obstetric unit. Participants One hundred and twenty-eight consecutive women with mitral. stenosis. Demographics The mean age was 27 years and 38 women (30%) were primigravidae. Seventy-eight (61%) women had their first cardiac evaluation in the third trimester. Fifty-four women (42%) of these women had mitral stenosis diagnosed for the first time in the index pregnancy. Twenty-nine (23%) had a previous mitral valvulotomy. Nineteen women (15%) developed hypertension during pregnancy 10 of whom had pre-eclampsia. Sixty-three women (49%) had a mitral valve area of less than or equal to 1.2 cm(2) with 11 having critical mitral stenosis (mitral valve area less than or equal to 0.8 cm(2)). Atrial fibrillation was present in 12 women. Most women (87%) required medical therapy to control the heart rate. Outcome in persistent symptomatic women Intervention was considered in 37 women (29%) who remained symptomatic, 11 (9%) of whom had a calcified mitral valve. The remaining 26 women were scheduled for balloon mitral valvulotomy during pregnancy, 20 of whom had balloon mitral valvulotomy with good effect (16 antepartum; 4 postpartum). In seven women, scheduled balloon mitral valvulotomy was not performed because of advanced preterm labour (n = 5), fetal distress (n = 1) and preterm labour with fetal distress (n = 1). These seven, together with the 11 with calcific mitral stenosis, were managed conservatively with good outcome. Maternal complications Fifty-one percent had maternal complications, the majority occurring at their initial admission to hospital. Pulmonary oedema was the most frequent. Multiple logistic regression analysis showed that the severity of stenosis assessed by measurement of the mitral valve area by echo-Doppler was the most powerful predictor of maternal pulmonary oedema. The other factors were late antenatal presentation, presence of symptoms prior to the index pregnancy and diagnosis of cardiac disease for the first time in the index pregnancy. Conclusion Despite serious disease, women with persistent symptoms treated either by balloon mitral valvulotomy where feasible, or conservatively with close noninvasive monitoring, had a satisfactory fetal and maternal outcome.