[Effects of oral contraceptives on the vascular wall (author's transl)].

The vascular complications of oral contraceptive treatment affect both arteries and veins, and vessels of all calibres in the systemic, pulmonary and portal circulations may be involved. In most cases thrombophlebitis develops under the combined influence of drug-induced blood changes and alterations in the vascular wall. Thickening of the connective and muscular fibers of the intima is commonly found, either isolated or associated with proliferation of the endothelium and/or thickening of the tunica media. These lesions are unrelated to those of atherosclerosis. Systematic investigations being impossible, the true incidence and extent of vascular wall alterations are necessarily under-estimated. The physiopathology of these non-specific lesions is unknown, but synthetic oestrogens seem to be mainly responsible for their occurence. Oestrogens might act on the vascular wall either directly or through changes in blood composition. Such lesions unquestionably have clinical repercussions.