A growing number of women are being identified who might require or benefit from anticoagulation therapy during pregnancy. Indications include prior history of thromboembolic complications, history of recurrent early pregnancy loss, and identification of genetic or acquired thrombophilias. The treatment of choice during pregnancy is, currently, either heparin or low-molecular weight heparin. However, when drug reactions to these agents occur, we are severely limited in terms of other options for therapy. Warfarin is teratogenic in early pregnancy and newer agents do not enjoy a wide experience under these circumstances. In this post, I review the limited literature on fondaparinux (ARIXTRA) and offer some guidelines for use in pregnancy in response to a reader's excellent questions. I would certainly appreciate any feedback regarding my thoughts on this from the worldwide medical community. We are all here to learn and share ideas!