An audit of pregnant women with prosthetic heart valves at a tertiary hospital in South Africa: a five-year experience

Background: Cardiac disease in pregnancy is a common problem in under-resourced countries and a significant cause of maternal morbidity and mortality. A large proportion of patients with cardiac disease have prosthetic mechanical heart valve replacements, warranting prophylactic anticoagulation. Aim: To evaluate obstetric outcomes in women with prosthetic heart valves in an under-resourced country. Methods: A retrospective chart review was performed of 61 pregnant patients with prosthetic valve prostheses referred to our tertiary hospital over a five-year period. Results: Sixty-one (6%) of 1 021 pregnant women with a diagnosis of cardiac disease had prosthetic heart valves. Fifty-nine had mechanical valves and were on prophylactic anticoagulation therapy, three had stopped their medication prior to pregnancy and two had bioprosthetic valves. There were forty-one (67%) live births, two (3%) early neonatal deaths, 12 (20%) miscarriages and six (10%) stillbirths. Maternal complications included mitral valve thrombosis (n = 4), atrial fibrillation (n = 8), infective endocarditis (n = 6), caesarean section wound haematomas (n = 7), broad ligament haematoma (n = 1) and warfarin embryopathy (n = 4). Haemorrhagic complications occurred in five patients and all five required blood transfusions. Conclusion: Prophylactic anticoagulation with warfarin in patients with mechanical heart valve prostheses was associated with high rates of maternal and neonatal complications, including significant foetal wastage in the first and early second trimesters of pregnancy. Health professionals providing care for pregnant women with prosthetic heart valves must consistently advise on family planning matters, adherence to anticoagulation regimes and consider the use of prophylactic anticoagulant regimens other than warfarin, particularly during the first trimester of pregnancy.