Serial changes in plasma fibrinogen concentration and fibrinolytic activity in African women on oral contraceptive pills.
Several retrospective epidemiological studies suggest that there is an association between the use of oral contraceptive pills and increased risk of intravascular thrombosis. The present study reports on several changes in fibrinogen concentration and fibrinolytic activity after prolonged use of oral contraceptives in African women. Fibrinolytic activity by euglobulin lysis time (ELT) and plasma fibrinogen concentration (PFC) by clot weighing method were assessed among 20 African women who were new users of combined oral contraceptives (OCP). They were tested at pre-treatment and serially at six monthly intervals over a three year period. There was consistently a significant increase in fibrinogen levels (p < 0.001) and euglobulin lysis time (p < 0.001) with increasing duration of use of oral contraceptive pills. There was a positive correlation between the mean fibrinogen levels and ELT (r = 0.89, p < 0.01), and a negative correlation between fibrinogen and plasminogen activator content of fibrinolytic system (r = -0.84, p < 0.01). The mean fibrinogen values during OCP use were substantially higher than at pre-treatment. We conclude that although African women may have a low predisposition to thrombosis, their risk of having fibrin defect is increased after prolonged use of oral contraceptive pills. We suggest a clinical epidemiological study to provide a better understanding of the haemostatic changes observed in African women.
Famodu
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Department of Haematology, Faculty of Medicine, University of Benin, Edo State, Nigeria.
D000293:Adolescent; D000328:Adult; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects*; D016903:Drug Monitoring; D045166:Estradiol Congeners / Q000009:adverse effects*; D004997:Ethinyl Estradiol / Q000009:adverse effects*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D005342:Fibrinolysis / Q000187:drug effects*; D006801:Humans; D008137:Longitudinal Studies; D009549:Nigeria; D009644:Norgestrel / Q000009:adverse effects*; D045167:Progesterone Congeners / Q000009:adverse effects*; D013997:Time Factors
D003277:Contraceptives, Oral, Combined; D045166:Estradiol Congeners; D045167:Progesterone Congeners; D009644:Norgestrel; D004997:Ethinyl Estradiol; D005340:Fibrinogen