Classification of endometriosis

An international working group with representation of the American Association of Gynecologic Laparoscopists (AAGL), the European Society for Gynaecological Endoscopy (ESGE), the European Society of Human Reproduction and Embryology (ESHRE), and the World Endometriosis Society (WES) convened to explore the possibility of developing an international classification for endometriosis. ESHRE was represented by Drs Carla Tomassetti and Andrew Horne.

At the start of the project, a review was conducted to explore the existing endometriosis classification, staging and reporting systems and how these were validated. The report of this exercise has been published in HROpen, and simultaneously in JMIG and FVVO.

In a second step, the working group defined and agreed on the definition of 46 terms relevant for endometriosis, and its description/classification. The International Terminology for endometriosis has also been published in HROpen, and simultaneously in JMIG and FVVO.

A last preparatory step was to investigate, through an international survey, the uptake of the current classification systems and the requirements for a future new system. The results of the survey are currently in publication.

Upon discussion of the results gathered in the exploratory phase of the project, ESHRE has decided not to proceed to the development of a consensus-based descriptive or classification system for endometriosis, arguing that a clinically relevant and internationally-accepted classification system would need to be developed from data rather than consensus, and this would require a formal research project set-up.