Endometriosis staging classifies the extent and anatomical distribution of disease found at surgery or on imaging. No single system captures every clinically relevant dimension — severity, deep-disease anatomy, surgical complexity, and fertility prognosis are each best described by a different tool. This calculator lets surgeons apply and compare four widely used systems — rASRM, ENZIAN, AAGL 2021, and the Endometriosis Fertility Index (EFI) — from the same set of intraoperative findings. Each answers a different question, and their evidence bases differ: the EFI is the only one of the four externally validated to predict pregnancy after surgery, and is the system to use when counselling on fertility.
The most widely used staging system worldwide. It assigns points to peritoneal and ovarian implants (weighted by size and depth), ovarian and tubal adhesions, and cul-de-sac obliteration, producing a score that maps to Stage I (minimal), II (mild), III (moderate), or IV (severe). It is easy to apply and reproducible, but does not predict pain, depth of infiltration, or fertility.
Developed to describe deep infiltrating endometriosis that rASRM captures poorly. ENZIAN compartmentalizes disease by anatomical location — rectovaginal septum, uterosacral ligaments, bowel, ureter, bladder, and other structures — giving a structured description of retroperitoneal and deep disease that complements rASRM scoring.
A newer classification from the American Association of Gynecologic Laparoscopists (Abrao et al., 2021), designed to correlate more closely with surgical complexity. It grades disease across anatomical sites and levels, producing a complexity score intended to help anticipate the difficulty of surgical excision.
Unlike the staging systems above, the EFI is a prognostic score rather than a stage. Validated by Adamson and Pasta (2010), it combines historical factors (age, duration of infertility, prior pregnancy) with surgical findings — including the least function score of the tubes, fimbriae, and ovaries — to estimate the likelihood of non-IVF pregnancy after surgery.
Because each system answers a different question, surgeons increasingly document more than one: rASRM for severity, ENZIAN for deep-disease anatomy, AAGL 2021 for surgical complexity, and EFI for fertility counselling. Applying them together from a single operative assessment supports more complete documentation and patient counselling.