The effects of transdermal oestradiol and oral progestogens on haemostasis variables

Objective To evaluate the effects of 1 g (1 mg oestradiol) transdermal oestradiol gel continuously combined with 10 mg medroxyprogesterone acetate orally 12 days either monthly or every third month on haemostasis variables. Design An open, parallel stratified study. Setting Sahlgrenska University Hospital, Goteborg, Sweden Participants A total of 48 peri- and postmenopausal women less than 65 years of age participated in this study. Twenty-seven women, who had from 2 months to 3 years since their last period were included in group I. Twenty-one women, who were more than 3 years postmenopausal, comprised group II. Main outcome measures The following parameters were determined: von Willebrand factor antigen, factor VII antigen, fibrinogen, antithrombin, protein C, protein S, plasminogen activator inhibitor activity, tissue plasminogen activator antigen, prothrombin fragment(1+2), thrombin-antithrombin complex and platelets. Results Both regimens decreased fibrinogen, factor VII antigen as well as antithrombin. Conclusions These changes were mainly 'in an anti-thrombotic direction'. The overall impression is that the transdermally administered oestrogen in combination with an oral progestogen induced favourable, although slight changes in the haemostatic system. The possible influence of these changes on the risk of cardiovascular disease remains yet to be studied.