Endometriosis Fertility Index: is it better than the present staging systems?

Endometriosis is a complex disease, one aspect being the existence of multiple staging systems. The recent Endometriosis Fertility Index (EFI) is compared with other endometriosis infertility staging systems and three new studies assessing the EFI are reported.

The revised American Fertility Society classification system has historically been most widely used but does not predict pregnancy rates. The ENZIAN classification system is designed to describe more severe disease as an adjunct to the ASRM system, but does not predict pregnancy rates. The American Association of Gynecological Laparoscopists (now named AAGL) is developing a categorization system more focused on pain. Novel research in imaging, biomarkers, histology and the human genome may provide useful information to develop future classification systems. The EFI has recently been published as a validated prospective staging system that predicts non-assisted reproductive technology pregnancy rates in infertility patients following surgical diagnosis. Three other investigators have now validated the EFI.

The only validated endometriosis classification system that predicts a clinical outcome is the EFI. The EFI has now been validated by three additional investigators. Renewed interest in the importance and utility of classification systems will hopefully result in novel classification systems that are useful for other clinical presentations of endometriosis.