title: Endometriosis classification: an update.
abstract: OBJECTIVE
  Endometriosis remains an enigmatic disease for many reasons, not the least being a continued inability to stage its clinical presentation so that prognosis and treatment for both pain and infertility patients can be facilitated. This article reviews issues with current staging systems.
  
  
  RESULTS
  The revised American Fertility Society (rAFS) classification system has historically been the only classification system. Recently, the ENZIAN classification system, developed as an adjunct to the rAFS to describe more severe disease, has been introduced but is rarely used. More recently, the Endometriosis Fertility Index (EFI) that has been validated to predict pregnancy rates in infertility patients following surgical diagnosis and treatment of endometriosis was published. Currently, the AAGL is developing a categorization system that will be more focused on pain. Novel research in imaging, biomarkers, histology, and the human genome may provide useful information to develop future classification systems.
  
  
  CONCLUSIONS
  The only validated endometriosis classification system that predicts a clinical outcome is the EFI. It is to be hoped that renewed interest in the importance and utility of classification systems will result in novel classification systems that are clinically useful.
authors.affiliation: Fertility Physicians of Northern California, San Jose and Palo Alto, California, USA. info@fpnc.com
authors.forename: G David
authors.initials: GD
authors.lastname: Adamson
mesh_terms: D004715:Endometriosis / Q000145:classification* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000209:etiology; D017699:Pelvic Pain / Q000209:etiology; D011379:Prognosis