Printed in U.SA. ENDOMETRIOSIS IN LEBANON A CASE-CONTROL STUDY

To explore some of the risk factors for endometriosis, the authors compared 170 cases with 170 age-matched controls similarly undergoing laparoscopy at the American University of Beirut Medical Center between 1979 and 1981. The findings include a positive association with first-class admissions (odds ratio = 2.77) and a negative association with parity and gravkJity. Both associations are consistent with the findings of other studies. There was no association with occupational status, nationality, religion, marital status, or past medical history. endometriosis; fertility; social class Although endometriosis is described as "a strange and protean disease " (1) and "one of the most interesting lesions in gyne-cological practice " (2), there are few sys-tematic epidemiologic studies of the dis-ease, and most of our knowledge about it comes from clinical observations. No defin-itive explanatory model has been found to account for the varied symptomatology, and there is no completely satisfactory model of etiology. Theories of etiology include transportation-implantation by which menstrual blood and endometrium regurgitate through the fallopian tubes and subsequently implant on the ovaries and elsewhere in the pelvic cavity (3-6) and the embryologic theories which see endometri-osis as arising from an abnormal differen-Received for publication April 14,1986, and in final form May 29, 1986. 1