Hypofibrinolysis and other hemostatic defects in women with early reproductive failure.

The fibrinolytic system is involved in blood clot lysis and in other biolog ical processes that require extracellular proteolysis such as ovulation, bl astocyst implantation and throphoblastic invasion. An impaired fibrinolytic capacity is a common feature in women suffering from unexplained early rec urrent pregnancy loss. We carried out a prospective study with 114 patients . Three groups were established: Group 1: women who had two or more unexpla ined miscarriages of < 12 weeks of gestation (n = 52). Group 2: women who h ad 2 or more embryo-implantation failure after embryo-transfer with good qu ality embryos in assisted reproduction (n = 46). Group 3: women who had 2 o r more embryo-implantation failure after embryo-transfer and one early loss of a pregnancy achieved in a cycle of assisted reproduction ( n = 16). Fib rinolytic pattern pre and post-occlusion test was carried out: ECLT, PAI-1i , PAI-lb, t-PAi, t-PAb. In addition other studies were performed: LAG, ACA IgG and IgM, fibrinogen, factor XII, APCR. A high prevalence of thrombophil ic defects and hypofibrinolysis was observed in the three groups. The fibri nolytic pattern was similar in the three groups, although a prolonged pre o cclusion ECLT was more frequent in women with primary infertility (Group 2) . Isolated hypofibrinolysis was found in 50% of the patients. The remaining patients with hypofibrinolysis presented combined defects with LAG, ACA an d abnormal APCR. The fibrinolytic pattern in women with or without antiphos pholipid antibodies was similar, although an elevated pre occlusion PAI-1i was more common in women without antiphospholipid antibodies. High prevalen ce of fibrinolytic abnormalities observed in women with unexplained early r ecurrent pregnancy loss and in women with repeated failure implantation aft er embryo-transfer in assisted reproduction, suggests that hypofibrinolysis could be a parameter of early reproductive failure.