Management of iliofemoral thrombosis in a pregnant patient with heparin resistance.

A 25-year-old primiparous woman presented at 30 weeks of gestation with suspected deep vein thrombosis of the left leg. Results of initial noninvasive tests were not in agreement and subsequent venographic findings revealed left iliac vein thrombosis. Treatment was initiated with continuous intravenous unfractionated heparin sodium for 3 days and then switched to twice-daily subcutaneous unfractionated heparin. Unfractionated heparin, 60,000 U per 24 hours, was required to maintain the activated partial thromboplastin time within the therapeutic range, which posed problems because of large volumes of injection. Therapy with subcutaneous low-molecular-weight heparin was successfully substituted and the patient had an uncomplicated full-term deliver.