Association between oral contraceptive use and thromboembolism: a new approach to itsinvestigation based on plasma fibrinogen chromatography.
Longitudunal and cross-dectional blood coagulation studies were made in patients receiving oral contraceptive therapy and in unmedicated women used as control subjects.  These studies have included use of a new procedure, plasma fibrinogen chromatgraphy, which, by assay for a high molecular weight fibrinogen complexes in plasma, detects or excludes the presence of small thrombi, even when these are of the clinically silent type.  New contraceptives users (n=154) received either Ovulen (100 pg of mestranol) or Demulen (50pg of ethinyl estradiol) and were followed serially for one year.  During the cross-sectional study (193 women and 1,350 samples), serial examination was preformed on those taking oral contraceptives for 3 months to 10 years.  Over-all, pathologic plasma fibrinogen chromatographic findings, indicative of thrombosis, were detected in 6 per cent of hte control examinations and in 27 per cent samples from oral contraceptive users.  These findings suggest that oral contraceptive users developed mainlyclinically silent thrombotic lesions, with four-to-fivefold greater frequency than the control subjects.  Consequently, it is inferred that they are at four-to fivefold greaterrisk of developing clinically overt disease, a risk factor estimate in line with that derived by epidemiologic study.
D000510:Alpha-Globulins / Q000032:analysis; D000991:Antithrombins / Q000032:analysis; D001780:Blood Coagulation Tests; D002845:Chromatography; D003276:Contraceptives, Oral / Q000009:adverse effects*; D005176:Factor XIII / Q000032:analysis; D005260:Female; D005340:Fibrinogen / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D010958:Plasminogen / Q000032:analysis; D011655:Pulmonary Embolism / Q000139:chemically induced; D012189:Retrospective Studies; D013923:Thromboembolism / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis; D013997:Time Factors; D000515:alpha 1-Antitrypsin
D000510:Alpha-Globulins; D000991:Antithrombins; D003276:Contraceptives, Oral; D000515:alpha 1-Antitrypsin; D005340:Fibrinogen; D010958:Plasminogen; D005176:Factor XIII