Relationship between the prognosis of conception and the location of pelvic involvement in endometriosis: significance of the TOP (tube, ovary, peritoneum) classification

To determine the main factors that affect the prognosis for conception in endometriosis-associated infertility, 99 infertile patients with laparoscopically confirmed endometriosis were classified according to the new TOP classification, which we have developed to evaluate the severity of endometriosis by site, i.e., fallopian tubes (T), ovaries (O) and the peritoneum (P). According to the TOP classification, a negative correlation between the pregnancy rate after treatment and the severity of lesions was noted in case of tubal and peritoneal involvement, but not when the ovaries were involved. If there was no tubal involvement or only unilateral tubal involvement, high pregnancy rates were achieved for patients with ovarian endometrioma (87%) and for those with partial or complete posterior cul-de-sac obliteration (83%). The results suggest that for endometriosis-associated infertility, the treatment modality should be selected according to the severity of tubal involvement, which is considered to contribute to infertility more than ovarian or peritoneal lesions.