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 empha sis 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. st enosis. Demographics The mean age was 27 years and 38 women (30%) were primigravida e. Seventy-eight (61%) women had their first cardiac evaluation in the thir d trimester. Fifty-four women (42%) of these women had mitral stenosis diag nosed for the first time in the index pregnancy. Twenty-nine (23%) had a pr evious mitral valvulotomy. Nineteen women (15%) developed hypertension duri ng pregnancy 10 of whom had pre-eclampsia. Sixty-three women (49%) had a mi tral 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 th erapy to control the heart rate. Outcome in persistent symptomatic women Intervention was considered in 37 w omen (29%) who remained symptomatic, 11 (9%) of whom had a calcified mitral valve. The remaining 26 women were scheduled for balloon mitral valvulotom y during pregnancy, 20 of whom had balloon mitral valvulotomy with good eff ect (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). Thes e seven, together with the 11 with calcific mitral stenosis, were managed c onservatively with good outcome. Maternal complications Fifty-one percent had maternal complications, the ma jority occurring at their initial admission to hospital. Pulmonary oedema w as the most frequent. Multiple logistic regression analysis showed that the severity of stenosis assessed by measurement of the mitral valve area by e cho-Doppler was the most powerful predictor of maternal pulmonary oedema. T he other factors were late antenatal presentation, presence of symptoms pri or to the index pregnancy and diagnosis of cardiac disease for the first ti me 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 outcom e.