RETROSPECTIVE STUDY OF MATERNAL AND FETAL OUTCOME OF PREGNANT WOMEN WITH PROSTHETIC HEART VALVE DESEASE IN INKOSI ALBERT LUTHULI CENTRAL HOSPITAL FROM 2004 TO 2009

B Mazibuko, H Ramnarain, Hopolong Maise

Abstract


Rheumatic heart disease is still rampant in the developing world, in spite of improvements in socioeconomic factors and greater awareness. This necessitates heart valve replacement at a young age. This finding is not unexpected, because it is well known that rheumatic fever is still a common problem in poorly resourced countries. Bhatla et al (2003), (New Delhi, India) and Abdel-Hady et al (2005) (Egypt), reported similar findings7,8.

The ideal choice of prosthesis for women of childbearing age is still unresolved despite advancements in the design of prosthetic heart valves. A mechanical prosthesis although durable and with an excellent hemodynamic performance, requires lifelong anticoagulation to prevent thromboembolic complications.4,8 A bioprosthesis avoids the need for anticoagulation but confers only a temporary advantage because pregnancy leads to accelerated structural deterioration that ultimately requires reoperation. Reoperation rates in mothers with a bioprosthesis range from 13% to 59% at 7 to 12 months after delivery.2,5,9 Pregnancy in women with a mechanical heart valve prosthesis carries increased risk for both mother and fetus.10 A hypercoagulable state exists in pregnancy because of increased levels of circulating fibrinogen and clotting factors, decreased fibrinolytic activity, increased platelet turnover, and increased viscosity.11,12 These factors greatly increase the risks of valve thrombosis and thromboembolic phenomena. Therefore, women with mechanical valves require more scrupulous anticoagulant treatment during pregnancy. The risks are greater for those with a mitral rather than aortic valve prosthesis.13 In this series, there was no incidence of thromboembolism or valve thrombosis. A similar study from South Africa reported no thromboembolic complications or death even though only 39% of mothers had an international normalized ratio within the target range.9 A report from India of a similar protocol for 47 pregnancies in 37 patients described valve thrombosis in 2 patients who were successfully treated surgically.8 Other studies have shown that oral anticoagulants provide adequate protection during pregnancy in mothers with prosthetic valves.1416