Is there a suitable method of anticoagulation in pregnant patients with mechanical prosthetic heart valves?
Open Access
- 25 May 2012
- journal article
- case report
- Published by Oxford University Press (OUP) in Interactive CardioVascular and Thoracic Surgery
- Vol. 15 (3), 484-488
- https://doi.org/10.1093/icvts/ivs178
Abstract
A best evidence topic was written according to a structured protocol in order to identify the mode of anticoagulation that has the best safety profile for both the mother and the foetus in pregnant patients with mechanical prosthetic heart valves. A total of 281 papers were identified using the reported search, of which eight represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. The reported measures were foetal mortality, maternal mortality, congenital abnormalities and embryopathy, and maternal thromboembolic and haemorrhagic complications. The medical orthodoxy has warned of the combination of oral anticoagulation and pregnancy due to the well-documented warfarin embryopathy. Yet only one of the reported papers identified a greater incidence of foetal aberrations among warfarin use, with the highest reported rate being 6.4% and two of the assessed papers reporting no embryopathy at all. Foetal mortality with oral anticoagulation use ranged from 1.52 to 76%. All reported publications demonstrated a superior maternal outcome with warfarin use, with a range of thromboembolic events from 0 to 10% in comparison with 4 to 48% where heparin was used. Thus, it is concluded that warfarin is a more durable anticoagulant with a better maternal outcome despite it carrying a greater foetal risk. Although, in contrast to previous teaching, the risks of embryopathy are not the major drawback of oral anticoagulation. Heparin is consistently less effective, but may be preferred for the superior foetal outcome. Heparin usage during the first trimester reduces the foetal risk but is still associated with an adverse maternal outcome. While the focus for clinicians looking after pregnant women with mechanical heart valves may be to prevent maternal thromboembolic complications, the overriding concern for many women is to avoid any harm to their unborn child, even when this places their health at risk. Thus women with mechanical heart valves must be fully informed of the risks involved with different anticoagulation for an informed decision to be made.Keywords
This publication has 10 references indexed in Scilit:
- Maternal complications and pregnancy outcome in women with mechanical prosthetic heart valves treated with enoxaparinBJOG: An International Journal of Obstetrics and Gynaecology, 2009
- Anticoagulation for prosthetic heart valves in pregnancy. Is there an answer?Asian Cardiovascular and Thoracic Annals, 2007
- ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart DiseaseJournal of the American College of Cardiology, 2006
- Low-molecular-weight heparin for thromboprophylaxis in pregnant women with mechanical heart valvesThe Journal of Maternal-Fetal & Neonatal Medicine, 2006
- Anticoagulation in Patients with Mechanical Valves during PregnancyAsian Cardiovascular and Thoracic Annals, 2005
- Towards evidence-based medicine in cardiothoracic surgery: best BETSInteractive CardioVascular and Thoracic Surgery, 2003
- Anticoagulation of Pregnant Women With Mechanical Heart ValvesArchives of Internal Medicine, 2000
- Anticoagulation in pregnant women with mechanical heart valve prosthesesHeart, 1999
- Dose-dependent fetal complications of warfarin in pregnant women with mechanical heart valvesJournal of the American College of Cardiology, 1999
- Outcome of pregnancy in women with valve prostheses.Heart, 1994