title: Platelet and coagulation functions during triphasic oestrogen-progestogen treatment.
abstract: The purpose of this investigation was the longitudinal evaluation of the hemostatic system before and after 1, 3, and 6 months of treatment with a triphasic oestrogen-progestogen combination. No changes of circulating platelet aggregates, as an index of in vivo platelet aggregability, and of megathrombocytes, an indirect evaluation of accelerated thrombocytopoiesis, were observed. A very slight, but significant, increase of Fibrinopeptide A (FPA), a reliable index of thrombin formation, was found only after 1 month of treatment; after 3 and 6 months, the increase of FPA was not homogeneous and not significant. Antithrombin III activity (AT III) showed no modifications after the first month; after 3 months AT III increased to a small extent, and after 6 months it was similar to basal values. Our findings indicate that the triphasic combination does not modify platelet functions and induces a low-degree activation of coagulation counteracted by an increased activity of the physiological inhibitors of blood clotting.
mesh_terms: D000293:Adolescent; D000328:Adult; D000990:Antithrombin III / Q000097:blood; D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D005260:Female; D005344:Fibrinopeptide A / Q000032:analysis; D006801:Humans; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D012016:Reference Values; D013997:Time Factors
chemical_list: D003277:Contraceptives, Oral, Combined; D005344:Fibrinopeptide A; D000990:Antithrombin III