Vascular thrombosis and oral contraceptives - a risk correlated study.

An immunological mechanism of the vascular complications related to oral contraceptives (O.C.) was suggested by the demonstration of circulating anti-ethinylestradiol antibodies in several cases. According to the characteristics of the specific immunoglobulins (Ig), a test based upon Ig precipitability in 25% saturated ammonium sulfate was developed. This test was applied to several groups of women on O.C. with and without thrombosis, and to a control group. Results indicated: (1) that the test was positive in nearly 100% of women with a vascular thrombosis on O.C.; and (2) that the test could detect among healthy contraceptive users a group of women who may be considered as at risk. The role of adjuvant factors is considered.