Journal of the European Society for Gynaecological Endoscopy


Endometriosis classification, staging and reporting systems: a review on the road to a universally accepted endometriosis classification

International Working Group of AAGL, ESGE, ESHRE and WES, N. Vermeulen 1, M.S. Abrao 2, J.I. Einarsson 3, A.W. Horne 4, N.P. Johnson 5, T.T.M. Lee 6, S. Missmer 7, J. Petrozza 8, C. Tomassetti 9, K.T. Zondervan 10, G. Grimbizis 11, R.L. De Wilde *12

1 ESHRE, Central office, Meerstraat 60, Grimbergen, BE 1852, Belgium
2 Disciplina de Ginecologia, Departamento de Obstetricia e Ginecologia, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, , São Paulo, Brazil; Gynecologic Division, BP - A Beneficencia Portuguesa de Sao Paulo, São Paulo, SP, Brazil
3 Brigham and Women’s Hospital, Department of Obstetrics and Gynecology, Division of Minimally Invasive Gynecologic Surgery, Boston, MA, USA
4 University of Edinburgh, MRC Centre for Reproductive Health, QMRI, 49 Little France Crescent, Edinburgh, UK EH16 4TJ
5 Robinson Research Institute, University of Adelaide, Adelaide, South Australia
6 Magee Womens Hospital of UPMC, Department of Obstetrics, Gynecology and Reproductive Sciences, Pittsburgh, PA, USA
7 Michigan State University College of Human Medicine, Department of Obstetrics, Gynecology and Reproductive Biology, East Lansing, MI, USA; Harvard University T H Chan School of Public Health, Department of Epidemiology, Boston, MA, USA; World Endometriosis Research Foundation, WERF, London, UK
8 Massachusetts General Hospital Fertility Center, Department of Obstetrics and Gynecology, Boston, MA, USA
9 University Hospital Leuven, Department of Obstetrics and Gynaecology, Leuven University Fertility Centre, Leuven, Belgium
10 University of Oxford, Oxford Endometriosis CaRe Centre, Nuffield Department of Women’s & Reproductive Health, Oxford, Oxfordshire, UK; University of Oxford, Wellcome Centre for Human Genetics, Oxford, Oxfordshire, UK
11 Medical School, Aristotle University of Thessaloniki, 1st Dept Obstet Gynecol, Tsimiski 51 Street, Thessaloniki, Greece 54623
12 Carl von Ossietzky Universitat Oldenburg, University Hospital for Gynecology, Oldenburg, Germany.

Published online: Oct 22 2021


Background: In the field of endometriosis, several classification, staging and reporting systems have been developed. However, endometriosis classification, staging and reporting systems that have been published and validated for use in clinical practice have not been systematically reviewed up to now.

Objectives: The aim of the current review is to provide a historical overview of these different systems based on an assessment of published studies.

Materials and Methods: A systematic Pubmed literature search was performed. Data were extracted and summarised.

Results: Twenty-two endometriosis classification, staging and reporting systems have been published between 1973 and 2021, each developed for specific and different purposes. There is still no international agreement on how to describe the disease. Studies evaluating different systems are summarised showing a discrepancy between the intended and the evaluated purpose, and a general lack of validation data confirming a correlation with pain symptoms or quality of life for any of the current systems. A few studies confirm the value of the Enzian system for surgical description of deep endometriosis. With regards to infertility, the endometriosis fertility index has been confirmed valid for its intended purpose.

Conclusions: Of the 22 endometriosis classification, staging and reporting systems identified in this historical overview, only a few have been evaluated, in 46 studies, for the purpose for which they were developed. It can be concluded that there is no international agreement on how to describe endometriosis or how to classify it, and that most classification/staging systems show no or very little correlation with patient outcomes.

What is new? This overview of existing systems is a first step in working towards a universally accepted endometriosis classification.