Staging and Classification of Endometriosis:Current Systems and the Novel YAO Classification

Endometriosis is a kind of common gynecologic disease,which is benign but intricate.The revised American Fertility Society(rAFS) classification system has historically beenthe only classification system and the most widely used staging system.Recently,the ENZIAN classification system,developed as an adjunct to the rAFS to describe deeply infiltrating endometriosis(DIE) and the involvement of other organs has been introduced.More recently,the Endometriosis Fertility Index(EFI) that has been validated to predict non-IVF pregnancy rates in infertility patients following surgical diagnosis and treatment of endometriosis was published.YAO Classification is a novel system that based on laparoscopic exploration and pathology.YAO Classification is better at standardizingdescription,documentation,and analysis of endometriosis,especially DIE.