The effect of long-term steroid contraception on coagulation in Asian women

Abstract

Recently Asian women who seemed to be less prone to thromboembolism were found to develop coagulation changes similar to Caucasians when they were on oral contraceptives containing synthetic oestrogens. Since progestogen only contraceptive is also very popular with Asian women, it was thought necessary to find out whether this contraceptive had an effect on the coagulation system after long term use. A cross-sectional retrospective study of the effects of combined oral contraceptive pill (ethinyl oestradiol and norgestrel) and injectable progesterone contraceptive (medroxyprogesterone acetate) on coagulation, fibrinolysis and platelet function were investigated. There were 114 women who had been on oral contraceptive pills continuously for two years or more in the pill group and 127 women on two years or more of injectable progestogen in the progestogen group. They were matched for age, parity and ethnic group for the control group. The control groups were women who were not pregnant or recently pregnant, not on steroids of any kind and with no history suggesting coagulation disorders matched for age, parity and ethnic group. In the pill group, overall clotting time such as PT, KCCT, were decreased. Coagulation factors I, II, V and X were increased, fibrinolytic activity and plasminogen were increased, and platelet count and function not significantly changed. Antithrombin III was decreased. Thromboelastographic studies showed no significant change. In the progestogen group, there were very few coagulation changes. Fibrinogen was slightly increased. There was no change in fibrinolysis or platelet function.