Effects of three types of combined O.C. pills on blood coagulation, fibrinolysis and platelet function.

The results of a prospective longitudinal controlled study comparing the coagulation effects of a standard low-dose combined oral contraceptive (Microgynon 30), a desogestrel-containing pill (Marvelon) and a triphasic preparation (Triquilar) after one year's treatment in ethnic Chinese women is presented in this paper. In general the changes in coagulation parameters are similar to those seen in Caucasian women. The rise in Factor VII levels seen at 6 and 12 months in Marvelon users was not present to a significant degree in the other pill users. Antithrombin III levels remained unchanged in Microgynon and Marvelon users but with Triquilar there was a significant fall at 6 and 12 months of use. Whether these differences have any clinical relevance in the local Chinese population with low incidence of thromboembolism remains to be seen.