Endometriosis: Prevalence and anatomical distribution of endometriosis in women with selected gynaecological conditions: results from a multicentric Italian study
We have evaluated the prevalence of endometriosis in selected gynaecological conditions requiring surgery. 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 during the study period in 23 obstetrics and gynaecology departments in Italy between May 1991 and July 1992. Women with a previous diagnosis of endometriosis were specifically excluded. A total of 3684 subjects entered the study. Of these, 660 (mean age 31 years) were included for sterility, 409 (mean age 32) for chronic pelvic pain, 1880 (mean age 42) for fibroids and 735 (mean age 33) for benign ovarian cysts. During the surgical procedure surgeons were asked to examine the pelvis carefully to identify endometriosis. Out of the 660 women included for sterility, 195 [30%, 95% confidence interval (CI) 26–35] had endometriosis; the corresponding figures were 185 out of 409 (45%, 95% CI 39–52) for pelvic pain, 219 out of 1880 (12%, 95% CI 10–14) for fibroids and 257 out of 735 (35%, 95% CI 31–40) for ovarian cysts; these differences were significant (x23 heterogeneity, absence versus presence = 323.9, P < 0.001). Among women with endometriosis who entered the study for sterility, 51% were at stage 1, 22% at stage 2, 20% at stage 3 and 7% at stage 4. The corresponding figures for pelvic pain and fibroids were largely similar: 37%, 24%, 30%, 10% for women with pelvic pain, 36%, 11%, 45% and 8% for those with fibroids, but among cases with ovarian cysts stage 3 was over-represented (62% of cases). The most common sites of endometriosis were, in order of frequency, the ovaries considered together, the posterior cul de sac and uterosacral ligaments. Endometriotic implants were more common on the uterosacral ligaments and the posterior cul de sac among women with sterility and pelvic pain than in those with fibroids and ovarian cysts. The frequency of endometriosis was not directly related to age at surgery, but decreased with increasing parity in all the four criteria for entry groups.