title: Oestrogen-progestogen oral contraception and blood clotting: a long-term follow-up.
abstract: In a long-term study of women taking the combined oestrogen/progestogen oral contraceptives Ortho-Novin and Norinyl-1 the follow-up has been continued for three years and four years respectively.Acceleration of both "intrinsic" and "extrinsic" clotting tests and of specific factor VII and X assays, reported previously at the nine-month stage, persisted throughout the period of study. Acceleration of Chandler's tube platelet aggregation and hypercoagulable thrombelastographic patterns were recorded. There was, however, no evidence of a cumulative effect after the first nine months.
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests; D003276:Contraceptives, Oral / Q000008:administration & dosage*; D005167:Factor VII / Q000032:analysis; D005170:Factor X / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008656:Mestranol / Q000008:administration & dosage*; D009640:Norethindrone / Q000008:administration & dosage*; D010973:Platelet Adhesiveness; D011517:Prothrombin Time; D013916:Thrombelastography
chemical_list: D003276:Contraceptives, Oral; D005167:Factor VII; D005170:Factor X; D008656:Mestranol; D009640:Norethindrone