title: Action of hormonal contraceptives on the coagulation system and some of its inhibitors.
abstract: Changes in the level of inhibitors of the coagulation system, primarily of thrombin neutralizing factors have been studied during the prolonged use of four products of contraceptive preparations containing various amounts of oestrogens and progestogens, two fixed dose pills (Bisecurin, Ovidon), a low dose combination pill (Rigevidon) and a biphasic preparation (Anteovin). Thrombelastographic values referred to hypercoagulability while the results of other examinations indicating activation of the coagulation system did not show definite changes in comparison with the control. The activity and quantity of antithrombin III decreased but never below 80%. Except Anteovin all contraceptives significantly enhanced alpha 1-antitrypsin while alpha 2-macroglobulin levels, remained nearly the same as the control values. Attention is called to that the increased alpha 1-antitrypsin level may be a biochemical risk factor. The results showed that the increased coagulability and disposition to thromboembolic disorders caused by hormonal contraceptives may be attributed not only to the decrease of thrombin inhibitors but also to increased alpha 1-antitrypsin levels which may cause increased inhibition of the fibrinolytic system.
mesh_terms: D000293:Adolescent; D000328:Adult; D000990:Antithrombin III / Q000037:antagonists & inhibitors; D001777:Blood Coagulation / Q000187:drug effects*; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D004997:Ethinyl Estradiol / Q000009:adverse effects*; D019304:Ethinyl Estradiol-Norgestrel Combination; D005040:Ethynodiol Diacetate / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008656:Mestranol / Q000009:adverse effects*; D009644:Norgestrel / Q000009:adverse effects*; D000515:alpha 1-Antitrypsin / Q000032:analysis; D000511:alpha-Macroglobulins / Q000032:analysis
chemical_list: D003277:Contraceptives, Oral, Combined; D003278:Contraceptives, Oral, Hormonal; D000515:alpha 1-Antitrypsin; D000511:alpha-Macroglobulins; D009644:Norgestrel; D004997:Ethinyl Estradiol; D005040:Ethynodiol Diacetate; D019304:Ethinyl Estradiol-Norgestrel Combination; C018467:Bisecurin I; D000990:Antithrombin III; D008656:Mestranol