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Hormonal contraception and thromboembolic disease: Effects of the oral contraceptives on hemostatic mechanisms

1971; Pergamon Press; Volume: 23; Issue: 10-11 Linguagem: Inglês

10.1016/0021-9681(71)90008-7

1878-0679

Marion Dugdale, Alfonse T. Masi,

Antiplatelet Therapy and Cardiovascular Diseases

Clinical and epidemiological data indicate that the oral contraceptives are thrombogenic. The important papers concerning the effects of oral contraceptives on hemostatic mechanisms were reviewed. This report summarizes the effects of oral contraceptives on: (1) platelet number and function; (2) tests of coagulation; (3) tests of specific clotting factors; and (4) tests of fibrinolysis and compares them with the findings in pregnancy, and in individuals taking estrogens or progestogens alone. Oral contraceptives, or estrogens alone, lead to an increase in platelet adhesiveness and aggregability. The oral contraceptives also enhance coagulability but induce little change in the fibrinolytic system. Progestogens alone enhance fibrinolysis without altering platelet function or coagulation. Pregnancy enhances coagulation and depresses fibrinolysis. It increases platelet reactivity but to a less extent than does the use of the hormonal contraceptives. Tentatively we conclude that the thrombogenic potential of the oral contraceptives appears to reside in the estrogenic components and may be due to their effect on platelet function rather than their effect on coagulation. Addition of this effect to the hormonally-induced vascular lesions and stasis may encourage thrombus formation. Further study of the effect of these hormones as it pertains to intravascular clotting is needed.