The Effect of Oral Contraceptives on Coagulation and Fibrinolytic Parameters in the Chinese – A Prospective Study

Summary

Thirty-two Chinese and 7 Caucasians were studied prospectively for 12 months for the effects of oral contraceptives (OC) on certain coagulation and fibrinolytic parameters. In both ethnic groups there was an increase in α₁ antitrypsin level. There was no significant change in antithrombin III concentration measured either by radioimmunoassay (At-III-RIA) or chromogenic assay (anti Xa-chromogenic) in the Chinese, but a significant decrease in anti Xa-chromogenic at 7 months and At-III-RIA at 12 months in the Caucasians. Also, α₂ plasmin inhibitor (α₂PI) levels were unchanged in the Chinese but a significant increase occurred in the Caucasians at 12 months. Enhanced fibrinolytic response to venous occlusion was demonstrated in the Chinese at 12 months but not in the Caucasians.

Keywords

Oral contraceptives - Antithrombin III - α₂ plasmin inhibitor - Fibrinolytic response - Chinese - Caucasians

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