**4. Potential methods for the correction of hemostasis and fibrinolysis pathologies within the IVF program**

Analysis of publications shows that correction of imbalanced homeostatic and fibrinolytic responses may be used in case of hormonal load within the IVF program accompanied by thrombophiia or present thrombogenic risk factors in a patient (Martinez-Zamora et al., 2011; Nelson & Greer, 2008; Rova et al., 2012; Urman et al., 2005). This is reasonable to determine thrombotic readiness, which becomes evident through the increase of general coagulation activity and thrombinemia and/or fibrinolysis suppression identified, for example, with the help of the thrombin generation assay upon detecting markers of thrombinemia and estimating fibrin clot lysis time for the fibrin obtained from euglobulins (Lisman et al., 2005; Wichers et al., 2009).

The use of heparins may become one of the methodologies aimed at the decrease of thrombogenicity and increase of IVF efficacy (Nelson & Greer, 2008; Urman et al., 2009). Still, there are no clear indications for the selection of women that need heparin prophylaxis within the IVF cycle.

Correction of hypofibrinolysis within IVF cycle also offers some difficulties for there are no published evidence of any successful drug therapy. Moreover, the hypothetic possibility to use pharmaceutical drugs - fibrinolysis activators (streptokinase, urokinase, and tissue plasminogen activator) - cannot be considered due to the absence of acute thrombosis. In the study conducted by Bjornsson et al. (1989), regular intake of aspirin in high doses (650 mg every 12 hours) caused the acceleration of fibrinolysis. But the mechanism of this effect is not absolutely clear, whereas the use of acetylsalicylic acid in high doses is unsafe due to the potential ulcerogenic effect. Nevertheless, it has been known for about 50 years that some stimuli (venous occlusion, physical load, desmopressin) lead to the acceleration of fibrinolytic responses facilitated by the fast increase of t-PA in blood due to its enhanced secretion by vascular endothelium. The effects of intermittent pneumatic compression (IPC) used to decrease the occurrence of postoperative venous thrombosis became our interests(Browse et al., 1977; Jacobs et al., 1996; Januszko et al., 1967; Holemans, 1963; Keber et al., 1979; Tarnay et al., 1980; Turpie et al., 1977; Weitz et al., 1986). Macdonald et al. (2003) published the results of their randomized pilot study demonstrating the efficacy of heparin prophylaxis combined with IPC in the course of neurosurgical invasions. The study conducted by Tarney et al. (1980) showed that intermittent compression of the calf, along with the increase in linear blood velocity and the decrease in venous stasis, increases local and systemic fibrinolytic potential (according to the shortened fibrin clot lysis time) in patients with acute myocardial infarction and prolonged movement disorders. Thus, the larger the volume of the compressed tissue gets, the more apparent became the response. The increase in blood and t-PA fibrinolytic activity after mechanical exposure on blood vessels is supported by the results presented by many authors (Bjornsson et al., 1989; Christen et al., 1997; Jacobs et al., 1996; Pandolfi et al.,1968; Salzman et al., 1987; Tarnay et al., 1980). However, we were not able to find any published data on the dynamics of PAI-1 activity. In the meantime, the correlation of the activities presented by these participants of the fibrinolysis system determines its overall efficacy. Some publications relate the mechanism of the IPC antithrombotic effect to the inhibition of coagulation cascade due to the expression of the tissue factor pathway inhibitor (TFPI) into blood flow and the decrease in the level of factor VIIa (Chouhan et al., 1999; Christen et al., 1997). Currently IPC is used worldwide for thromboprophylaxis in patients with strokes, after arthroplasty and a number of other operative invasions, in medical emergency,and applicable, firstly, in cases when administration of anticoagulants is dangerous due to the development of haemorrhage (Geerts & Selby, 2003; Gordon et al., 2012). As a rule, IPC is performed on the lower extremities, though some publications present positive results for the upper extremities compression (Knight & Dawson, 1976). Despite the fact that legs weigh more than arms, it was proved that forearm veins have considerably more t-PA than leg veins (Pandolfi et al., 1968). In our study this form of IPC was used to activate fibrinolytic responses within the IVF program and in the presence of relevant indications.
