DECREASED PLASMA FIBRIN DEGRADATION PRODUCTS DURING HORMONAL-STIMULATION FOR IN-VITRO FERTILIZATION

In vitro fertilisation with embryo transfer (IVFET) is associated with an increased risk of venous thrombosis. In order to determine to whic h extent the hormonal preparation required for IVFET could be involved in this complication, we have measured major plasma fibrinolytic comp onents in 13 women before and during the ovarian stimulation. After pi tuitary desensitization with buserelin, plasma levels of fibrin degrad ation products (FbDP) and fibrinogen were significantly decreased. Tis sue-type plasminogen activator antigen (t-PA), plasminogen activator i nhibitor 1 antigen (PAI-1), FbDP and fibrinopeptide A remained unchang ed. After a subsequent stimulation by human menopausal gonadotropins, FbDP plasma levels remained low, while fibrinogen returned to normal l evels. t-PA antigen and PAI-1 antigen plasma levels decreased and were correlated with increased serum estradiol levels. Therefore, estradio l could be involved in the regulation of the fibrinolytic balance to s ome extent; during IVFET hormonal preparation, a decreased plasma fibr inolytic capacity can be questioned, thus favouring the appearance of a thrombotic event.