Left : right side ratio of endometriotic implants in the pelvis

The frequency of endometriotic lesions in the right and left hemipelvis was analysed in 856 women with endometriosis. Eligible for the study were women with primary or secondary sterility, chronic pelvic pain, fibroids or benign ovarian cysts requiring laparoscopy or laparotomy consecutively observed between May 1991 and July 1992 in 23 obstetric and gynecology departments in Italy. Women with a previous diagnosis of endometriosis were excluded. A total of 3684 women entered the study. Of those, 856 had endometriosis and are considered in the present analysis.