Abstract

PIP: 78 endometrial biopsies from 58 patients (ages 21-50 years) taking both sequential and combination oral contraceptives, and 10 extra-uterine tissues were studied for vascular changes. Of the endometria examined, 31.3% revealed endothelial hyperplasia in coiled and basilar arteries as well as sinusoids, and 5.1% were so extensive as to reduce the caliber of the overall lumen. Smooth muscle hyperplasia was evident in 82%, of which 3.4% were considered extensive. Similar changes were observed in the skin, colon, cervix, ovary and breast tissue, suggesting that while end organ response is readily detected, the vascular changes are not wholly confined to the uterus. The incidence was higher in patients on sequential therapy (endothelial hyperplasia in 73%, smooth muscle hyperplasia in 58%) than in those on combination therapy (endothelial hyperplasia in 48%, smooth muscle hyperplasia in 33%). There appeared to be no relationship of incidence to duration of therapy, and lesions did not appear to be progressive. Studies of the endometrium of pregnancy, hyperplasia and polypi revealed similar changes in all conditions, though rarely to the same degree. Oral contraceptives used for long periods of time could result in thick-walled vessels and narrowed lumina; the relationship of such alterations to arteriosclerosis remains to be determined. There is a distinct possibility that endothelial hyperplasia may be related to thromboembolism, since venous channels and sinusoids show endothelial hyperplasia as well as arteries.