The unusual case of a 31-year old female, pregnant for the second time and in the sixth week of pregnancy, who developed a very localised low mid-aortic thrombosis with typical claudication and associated clinical findings, is presented 21 years after corrective surgery for this condition. The authors wish to emphasize the fact that this case shows no similarity with the middle aortic syndrome, classically described by Debakey, in which major visceral branches of the lower abdominal aorta are involved. After ruling out, every possible classical cause of this condition, such as described in the discussion of this paper, the authors have to conclude that this situation was caused by increased red cell aggregation of the blood during pregnancy in a woman with moderate degree of hypoplasia of the abdominal aorta. After corrective surgery, the patient is still free of symptoms and of peripheral atherosclerotic disease.
