The endometrial theory of ectopic pregnancy

Abstract

Various observers including ourselves, have demonstrated healthy endometrial tissue in tubal lumina. Sampson and Jacobsen, and others have proved beyond doubt that such endometrial tissue can and does implant itself and grow elsewhere displaying a preference for serous surfaces. Cases have been reported in the literature of endometrial tissue in the tubes. We have one such case.Many observers have found decidual tissue in tubes whether or not they were the site of pregnancy. We have found it present at the site of the pregnancy in 62 per cent of casual specimens, in 87½per cent of cases where we made a careful search and believe that it is present at the outset in 100 per cent of cases.In one case we succeeded in finding endometrial glands in this decidual tissue, proving that the decidual reaction was caused by the response of endometrial elements and not the tubal structure itself. The fact that the fibrin layer of Nitabusch can be demonstrated in these ectopic decidual tussues shows that the ectopic endometrium carries out its functions as completely as when it was on the uterine wall.The ectopic endometrial tissue was found in 1 out of 204 cases, an incidence of ½per cent. The ratio of ectopic to intrauterine pregnancy is about 1 to 202 (Schumann's18 series) in Farrar's19 series 4 to 309, a significant correspondence of statistics and the explanation of the frequency of ectopic gestation.