Q: Coumadin (warfarin) is contraindicated in pregnancy, except in one condition. Which one

Answer: prosthetic mehanical heart valves.

In pregnancy, warfarin can be continued after the first trimester in women with prosthetic heart valves.

Current guidelines recommend that the decision whether to use heparin during the first trimester or to continue oral anticoagulation throughout pregnancy should be made after full discussion of the aforementioned facts with the patient. The 2008 ACC/AHA guidelines recommend that patients who elect to stop warfarin between weeks 6 and 12 of gestation, to decrease the risk of fetal defects, should receive continuous IV, or dose adjusted subcutaneous (SQ) UFH or dose-adjusted SQ LMWH.

Reference:

1. Chan WS, Anand S, Ginsberg JS. Anticoagulation of pregnant women with mechanical heart valves: a systematic review of the literature. Arch Intern Med 2000;160:191–6.

2. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 2008; 52:e1.