Endometriosis classification for infertility.

The American Fertility Society (AFS) classification for endometriosis is a widely-used system for categorizing the severity of pelvic endometriosis. Although this classification represents a detailed description of the location and extent of disease, it has limitations when used to predict fecundity following treatment of the different stages of endometriosis. Concern regarding the inability of the AFS classification to discriminate between mild, moderate and severe disease in terms of pregnancy outcome is related to arbitrary assignment of point scores for each pathologic observation, and to arbitrary assignment of total scores to patients divided into severity categories. Establishment of empirically-derived scores for individual pathologic observations and identification of cut-off scores based on pregnancy outcome for each category would offer a reliable, clinically useful classification system for endometriosis in infertile women.