Effects of three types of combined O.C. pills on blood coagulation, fibrinolysis and platelet function
Prasad, R.N.; Koh, S.; Ratnam, S.S.
Contraception 39(4): 369-383
1989
ISSN/ISBN: 0010-7824 PMID: 2524360 DOI: 10.1016/0010-7824(89)90116-9Document Number: 360076
81 healthy Chinese women of proven fertility and between the ages of 18-34 years were recruited for this prospective and 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 1 year's treatment. Study participants were randomly allocated to 1 of the 3 pill types and were followed up at 3 and 6 months and thereafter yearly. The subjects were encouraged to come earlier if they experienced any problems. Each volunteer acted as her own control. Blood sampling was performed at pretreatment (control value) and at 6 months and 12 months of treatment. The samples were taken between days 22-24 of the menstrual cycle at the same time of the day. There were 24 subjects recruited for Marvelon, 27 for Microgynon 30, and 30 for Triquilar treatment. Physical characteristics of the subjects were comparable on entry and showed no statistically significant mean weight or blood pressure change at the end of 12 months of treatment when compared with pretreatment values. In the screening tests, there was no change in hemoglobin concentration and maximum elasticity of the clot, even after 12 months of treatment for all OC subjects under treatment when compared with pretreatment levels. A lowered hematocrit was seen only in Marvelon subjects at 6 months treatment; the hematocrit returned to pretreatment levels after 12 months of treatment. Significant shortening of Activated Partial Thromboplastin Time (APTT) was observed both with Microgynon 30 and Triquilar subjects but not with Marvelon subjects after 12 months of treatment. Significant shortening of prothrombin time was seen at both 6 and 12 months of Microgynon 30 treatment; this change was seen only after 12 months of Marvelon treatment and absent at 12 months in Triquilar subject. In thromboelastogram (TEG), a shortening of reaction and clotting time was observed in all subjects after 12 months of treatment without affecting any change in maximum clot elasticity. There was no significant change seen in Fibrinogen, Coagulation Factor VIIIC, and Factor VIIIR:Ag, even after 12 months of treatment in all subjects. No appreciable change in Factor II was seen in Microgynon 30 and Triquilar subjects, but in Marvelon treatment a significant increase was observed after 12 months treatment. Factor V showed an increase in Microgynon 30 subjects only at 12 months treatment and 6 months treatment for Triquilar subjects, but no change was seen in Marvelon subjects.