Fetal wastage syndrome is characterized by recurrent spontaneous abortion. Many syndromes are associated with recurrent fetal loss, including anatomical anomalies, endocrine/hormonal abnormalities, and coagulation defects, with coagulation defects accounting for similar to 30% of cases. Most procoagulant factor defects are due to inadequate fibrin-mediated implantation of the fertilized ovum into the decidua. However, blood protein/platelet defects leading to hypercoagulability and thrombosis are associated with thrombosis of placental vessels, precluding viability of the implanted ovum or later fetus. During the past 2 years, we have seen 46 patients with fetal wastage syndrome due to thrombosis-associated hemostasis defects. In this group, there have been three patients with sticky platelet syndrome, one patient with dysfibrinogenemia, four patients with congenital protein S deficiency, 35 patients with anticardiolipin antibodies, and one patient with a lupus anticoagulant. Patients were started on one low-dose aspirin (ASA), 81 mg per day preconception, at time of diagnosis, and low-dose s.c. porcine heparin at 5,000 units every 12 h was added immediately postconception. The combination of low-dose ASA plus low-dose s.c. porcine heparin was used throughout pregnancy, All patients achieving pregnancy have had uneventful, normal deliveries. It appears that blood protein/platelet defects leading to thrombosis and associated with recurrent fetal loss can be successfully managed with the use of preconception low-dose ASA, followed by immediate postconception addition of fixed low-dose porcine heparin, both used throughout pregnancy. Using this regimen, our success rate has been 100%. Ideal heparin doses, which might be much lower than our empirically chosen and currently used doses, remain to be defined in this particular indication.