A striking characteristic of thrombosis associated with oral contraceptive use is its localization to vessels that are only rarely the sites of spontaneous thrombosis in healthy, nonpregnant women in the same age group who do not use oral contraception. For example, thrombosis has been reported at such sites as the subclavian, axillary, femoral, renal, mesenteric, internal carotid, vertebral, basilar, and cerebral arteries, the hepatic, mesenteric, and cerebral veins, and intracranial venous sinuses. An increased incidence of myocardial infarction has also been noted, particularly in relatively older women who are cigarette smokers.
Infarction of the bowel consequent on the thrombotic occlusion of mesenteric vessels is of particular interest to internists because diagnosis, critical to survival, is difficult. Beginning in 1963, cases have been reported in which women taking oral contraceptives experienced mesenteric vascular occlusion. The syndrome has appeared in several forms. In some women, the occlusion (whether arterial or venous is