Low-molecular-weight heparin for thromboprophylaxis in pregnant women with mechanical heart valves.

Journal Article (Journal Article;Review)

BACKGROUND: Pregnancy in a woman with a mechanical heart valve is a life-threatening situation. Due to the inability of unfractionated heparin to prevent valvular thromboses, warfarin or other vitamin K antagonists have been the preferred anticoagulants for the mother. They are, however, potentially harmful to the fetus. With the advent of low-molecular-weight heparins, clinicians were hopeful for an alternative that was safe for the fetus, but more effective than unfractionated heparin, which carries a 29-33% risk of life-threatening thromboses and a 7-15% chance of mortality. Unfortunately, fatal thromboses have occurred with low-molecular-weight heparin as well. METHODS: We searched the MEDLINE database and other sources to identify cases of the use of low-molecular-weight heparin for thromboprophylaxis in women with mechanical heart valves. RESULTS: We found 73 cases and added three of our own for a total of 76. There were 17 thrombotic events (22%). Thirteen were valve thromboses, two were strokes, and two were myocardial infarctions. There were three deaths (4%). CONCLUSIONS: While pregnant women with mechanical heart valves who receive low-molecular-weight heparin for thromboprophylaxis are at extremely high risk of life-threatening thromboses, there is no evidence that low-molecular-weight heparin is inferior to unfractionated heparin.

Full Text

Duke Authors

Cited Authors

  • James, AH; Brancazio, LR; Gehrig, TR; Wang, A; Ortel, TL

Published Date

  • September 2006

Published In

Volume / Issue

  • 19 / 9

Start / End Page

  • 543 - 549

PubMed ID

  • 16966122

Pubmed Central ID

  • 16966122

International Standard Serial Number (ISSN)

  • 1476-7058

Digital Object Identifier (DOI)

  • 10.1080/14767050600886666


  • eng

Conference Location

  • England