OBJECTIVES: We are conducting a randomized double-blind placebo-controlled pilot study. The pilot study seeks to answer the question: Is a randomized double-blind placebo-controlled multicentre trial of low molecular weight heparin thromboprophylaxis feasible in moderate to high risk women post cesarean section with DVT detected by pelvic vein (MRV) or leg vein (leg compression ultrasound) imaging? Our ultimate goal is to determine: