Table I.

Historical overview of endometriosis classification/staging system.

Endometriosis classification/staging system	Publication year	Classification/staging based on	Intended purpose							Details	Reference
			Diagnosis/Pre-op assessment	Description	Staging	Treatment selection	Prediction of difficulty of surgery	Prediction of pain remediation/improved QoL	Prediction of conception
#ENZIAN classification	2021	Surgical observation or imaging	√	√						Non-invasive and surgical description system for endometriosis	(Keckstein et al., 2021)
Adhesion scoring system	2020	US	√						√	Pre-operative prediction of the pelvic adhesion status	(Ichikawa et al., 2020)
ENDOGRAM	2019	Disease markers in biopsy sample				√				Analysis of endometriotic tissues supporting therapeutic decisions	(Bouquet de Joliniere et al., 2019)
ENDORECT	2019	Clinical examination, US, MRI	√							Preoperative score to predict rectosigmoid involvement	(Chattot et al., 2019)
Bowel Endometriosis Syndrome (BENS) score	2017	Symptoms	√							Identify bowel endometriosis syndrome based on patient reported symptoms and QoL	(Riiskjaer et al., 2017)
Preoperative ultrasound-based endometriosis staging system (UBESS)	2016	US	√				√			Pre-operative staging and prediction of the level of complexity of laparoscopic surgery.	(Menakaya et al., 2016)
Classification of ureteral endometriosis	2015	Surgical observation	√	√	√					Clinical classification of urinary tract endometriosis	(Knabben et al., 2015)
EPHect SSF - EPHect MSF (surgical form)	2014	Surgical observation		√						Recording of surgical phenotypic information and related sample collections obtained at laparoscopy	(Becker et al., 2014)
Clinical score	2014	Symptoms	√				√			Predict DE presence before endometrioma surgery	(Lafay Pillet, et al., 2014)
LSD/MURO Classification	2013	Modified Virtual Colonoscopy	√							Descriptive imaging classification, with implied severity for rectogenital and disseminated endometriosis	(van der Wat et al., 2013)
ECO system	2012	Extent, symptoms and objectives				√				Determine most appropriate management	(Lasmar et al., 2012;2015)
Deep endometriosis staging form	2011	US			√					Staging system for DE based on ultrasonographic finding	(Coccia and Rizzello, 2011)
Endometriosis Fertility Index (EFI)	2010	Surgical observation + Patient parameters							√	Prediction of (non-IVF) pregnancy after surgery	(Adamson and Pasta, 2010)
ENZIAN classification	2005	Surgical observation (or MRI)	√1	√						Surgical classification for DE	(Keckstein et al., 2021, Tuttlies et al., 2005)
Chapron classification	2003	Surgical observation		√			√			Surgical classification for DE with suggested operative procedure	(Chapron et al., 2003a;2003b)
Revised ASRM classification	1997	Surgical observation		√	√					Adapted from rAFS score	(American Society for Reproductive Medicine, 1997)
TOP classification	1993	Surgical observation			√				√	Evaluate the severity of endometriosis by site, i.e., fallopian tubes (T), ovaries (O) and the peritoneum (P) and impact on PR	(Kurata et al., 1993)
Revised American Fertility Society (AFS) classification	1985	Surgical observation		√						Point system to determine stage/degree of endometriosis involvement	(American Fertility Society, 1985)
American Fertility Society (AFS) classification	1979	Surgical observation		√							(American Fertility Society, 1979)
Buttram classification	1978	Surgical observation		√					√	Classification of endometriosis in the infertile female (expanded from (Acosta, et al., 1973))	(Buttram, 1978)
Kistner classification	1977	Surgical observation		√					√	Classification as a tool to link pregnancy rates with the presence/extent of disease	(Kistner et al., 1977)
Acosta classification	1973	Surgical observation		√					√	Classify the extent of disease and relationship with pregnancy rate	(Acosta et al., 1973)

DE, deep endometriosis; ECO, disease extent complaints, objectives system, QoL, Quality of life; PR, pregnancy rate; US, ultrasound, #ENZIAN: the recently updated ENZIAN classification, which incorporates all types of endometriosis

¹In case of ENZIAN score based on MRI.