OBJECTIVE: To determine current practice patterns in the postpartum management of women at increased risk of thrombosis. METHODS: Physicians affiliated with the University of Toronto departments of Obstetrics and Gynecology, Rheumatology, Hematology, and Obstetric Medicine who provide care to pregnant women were mailed a questionnaire that presented 6 clinical scenarios involving postpartum management of a woman at risk for thrombosis, with (1) recurrent pregnancy loss and antiphospholipid antibody syndrome (APS) treated with aspirin (ASA) in the pregnancy; (2) 2 pregnancy losses and a low titer antiphospholipid antibody (aPL) treated with ASA and low molecular weight (LMW) heparin with placental insufficiency; (3) known APS and pregnancy loss treated with LMW heparin and delivered by cesarean section; (4) a previous 17 week fetal death and aPL; (5) a previous deep vein thrombosis while on oral contraception; and (6) systemic lupus erythematosus and secondary APS with a history of a stillbirth. Physicians were asked whether they would recommend postpartum coagulation, and if so to choose from a list of treatment options. RESULTS: Of the 71 questionnaires mailed, 44 were returned (62%). Three physicians replied that their practices do not include patients similar to those presented in the cases and chose not to respond to the clinical scenarios. Percentages of responders recommending treatment in each scenario were 29% for Case 1, 49% for Case 2, 63% for Case 3, 41% for Case 4, 51% for Case 5, and 58% for Case 6. Recommendation for treatment differed among medical specialties, with rheumatologists being less likely to treat in all cases. Prophylactic heparin was selected as the treatment of choice most frequently by those recommending anticoagulation 70% (84/120). CONCLUSION: Postpartum treatment recommendations for women at increased risk of thrombosis are variable across different practitioner specializations demonstrating clinical equipoise regarding therapy. More definitive research is needed and broader study of physicians involved in the care of these patients is planned to more accurately describe and understand the decision to treat these patients.