Diagnosis and management of endometriosis: summary of updated NICE guidance
BMJ 2025; 388 doi: https://doi.org/10.1136/bmj.q2782 (Published 31 January 2025) Cite this as: BMJ 2025;388:q2782Linked Practice
Collaboration is key in managing endometriosis
- 1National Institute for Health and Care Excellence, Manchester, UK
- 2Royal Cornwall Hospital, Truro
- 3NHS Cheshire and Merseyside, Liverpool
- Correspondence to S Rajesh sharangini.rajesh{at}nice.org.uk
What you need to know
A positive history in a first degree relative increases the likelihood of developing endometriosis
Do not exclude the possibility of endometriosis if transvaginal ultrasound scan is normal and history is suggestive
Both transvaginal ultrasound and pelvic magnetic resonance imaging should be considered for diagnosis and assessment of the extent of deep endometriosis
Endometriosis is a chronic condition where endometrium-like tissue grows outside the uterus, most commonly within the pelvis, and on organs such as ovaries, bladder, and bowel. In the UK, about one in 10 women of reproductive age (from puberty to menopause) has endometriosis.1
The condition is associated with varied clinical symptoms, including chronic pain in the lower back and pelvis, pain while menstruating, having sex, passing urine or stool, and infertility. Some women with endometriosis may not experience any symptoms, but for others it can have a substantial impact on their quality of life. In the UK, people with suspected endometriosis wait an average of eight years for a diagnosis.2 A prolonged time to diagnosis may lead to delay in appropriate management, monitoring, and disease progression.
The National Institute for Health and Care Excellence (NICE) guideline covering diagnosis and management of endometriosis was first published in September 2017. A topic update related to management of fertility as a priority was published in April 2024.3 This article summarises recently updated recommendations, specifically focusing on factors associated with time to diagnosis, including imaging, for those working in primary care.
Recommendations from this topic are for women and people with suspected or confirmed endometriosis, their families, and carers. Trans men and non-binary people also experience endometriosis. Therefore, this paper refers to “women” and “people” to reflect a range of identities.
Recommendations
NICE recommendations are based on systematic reviews of best available evidence and explicit consideration of cost effectiveness. When minimal evidence is available, recommendations are based on the guideline development group’s (GC’s) experience and opinion of what constitutes good practice. Evidence levels for the recommendations are given in italics in square brackets.
GRADE Working Group grades of evidence
High certainty—we are very confident that the true effect lies close to that of the estimate of the effect
Moderate certainty—we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low certainty—our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low certainty—we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect
History
This is a new recommendation. When assessing a person with signs and symptoms of endometriosis, the likelihood of developing endometriosis is higher if there is a history of the condition in a first degree relative.
Ask if any first degree relatives have a history of endometriosis, as this increases the likelihood of endometriosis.
[Recommendations based on the GC’s experience]
Ultrasound
The updated recommendations considered an evidence review from 20 studies that assessed diagnostics of endometriosis, which showed transvaginal ultrasound scan had moderate to high sensitivity (70% to 100%, very low to high quality of evidence) and high specificity (94% to 100%, moderate to high quality of evidence) for detection of deep endometriosis across a range of sites, including bowel, bladder, ureter, and ovaries (including endometrioma) (table 1). Although superficial endometriosis is the most common type of endometriosis, this subtype was not included in the recommendation as it is difficult to diagnose with transvaginal ultrasound or any other imaging tests accurately.
The strength of the recommendations related to performing transvaginal ultrasound scan in primary care has been upgraded from a weak “consider” recommendation in the previous guideline to a strong “offer” recommendation. Although the sensitivity and specificity are operator dependent, most non-specialist sonographers would be able to identify ovarian endometriomas, and possibly cases of deep endometriosis. Furthermore, an early transvaginal ultrasound scan may rule out other pathology such as fibroids or malignancy.
When a patient declines transvaginal ultrasound or it is otherwise not suitable, transabdominal scan is an alternative. In one prospective cohort study of 40 women with suspected endometriosis, transabdominal ultrasound showed high sensitivity (91%, low quality evidence) and moderate specificity (75%, very low quality evidence) in detection of deep endometriosis in the ovaries.6 Evidence from the same study showed that transabdominal ultrasound to identify deep endometriosis in the uterosacral ligaments showed low sensitivity (25%, low quality evidence) and high specificity (97%, low quality evidence).
Offer a transvaginal ultrasound scan to all women or people with suspected endometriosis, even if pelvic or abdominal examination is normal, to:
Identify ovarian endometriomas and deep endometriosis, including that involving the bowel, bladder, or ureter
Identify or rule out other pathology which may be causing symptoms
Guide management options and enable referral to an appropriate service, depending on the ultrasound findings.
This ultrasound scan should be organised by the person’s general practice.
[Recommendations based on very low to high certainty diagnostic evidence]
If a transvaginal ultrasound scan is declined or not suitable for the person, consider a transabdominal ultrasound scan of the pelvis.
[Recommendations based on the GC’s experience]
Referral criteria
These updated recommendations for referral criteria to secondary care services were based on the guideline committee’s experience only, and were made following consensus.
Superficial or microscopic endometriosis will not be identified by ultrasound scan in all cases, and diagnostic accuracy of ultrasound is operator dependent. Therefore, do not exclude endometriosis if an ultrasound scan is negative and there is clinical suspicion, and refer for further investigations even after a normal scan.
The recommendation related to referring to secondary care gynaecology services was strengthened from “consider” to “offer” referral, as women or people with suspected or confirmed endometriosis meeting criteria will need referral by general practice for further investigations and management. The recommendation related to referring to tertiary specialist endometriosis services directly was amended to include suspected or confirmed endometrioma as one of the criteria, in addition to deep endometriosis. Endometriomas are often associated with deep or severe endometriosis, and their management can be particularly complicated, especially if fertility is a consideration. For young women or people (aged 17 and under) with suspected or confirmed endometriosis, the strength of the recommendation was upgraded from “consider” in previous guidelines to “refer” in the updated one.
During assessment in primary care, people presenting with pain and symptoms of endometriosis should receive treatment with analgesics, neuromodulators, neuropathic pain treatments, or hormonal treatment, as appropriate, while further investigations or referrals are underway.3
Do not exclude the possibility of endometriosis if the abdominal or pelvic examination and ultrasound scan are normal, and recognise that referral may still be necessary even with a normal scan.
[Recommendation based on the GC’s experience]
Refer women or people with symptoms of, or confirmed, endometriosis to a gynaecology service (see the recommendation on gynaecology services) for further investigation and management if:
Initial treatment is not effective, is not tolerated, or is contraindicated, or
They have symptoms of endometriosis which have a detrimental impact on activities of daily living, or
They have persistent or recurrent symptoms of endometriosis, or
They have pelvic signs of endometriosis, but deep endometriosis is not suspected.
[Recommendation based on the GC’s experience]
Refer women or people to a specialist endometriosis service if they have suspected or confirmed:
Endometrioma, or
Deep endometriosis, including that involving the bowel, bladder, or ureter, or
Endometriosis outside the pelvic cavity.
[Recommendation based on the GC’s experience]
Refer young women or people (aged 17 and under) with suspected or confirmed endometriosis to a paediatric and adolescent gynaecology service, or specialist endometriosis service (endometriosis centre) for further investigation and management.
[Recommendation based on the GC’s experience]
Pelvic magnetic resonance imaging (MRI) scan
Currently, ultrasound is the primary investigation for diagnosis, and MRI is used for diagnosis and assessment of the extent of deep endometriosis and to guide treatment decisions. In these updated recommendations, both pelvic MRI and transvaginal ultrasound performed and interpreted by specialists in secondary care, including sonographers, should now be considered for the diagnosis and assessment of the extent of deep endometriosis.
An evidence review of 10 new studies was undertaken, which showed that diagnostic ability of MRI ranged from low to high sensitivity (39% to 100%, very low to moderate quality evidence) and moderate to high specificity (80% to 100%, very low to high quality evidence) for diagnosing deep endometriosis in various sites, including ovaries, vagina, rectosigmoid, rectovaginal septum, uterosacral ligaments, and bladder. Based on the evidence review for transvaginal ultrasound scan, when performed in the secondary care setting it could also be used for the diagnosis of deep endometriosis.
Consider specialist transvaginal ultrasound scan or pelvic MRI scan to diagnose deep endometriosis and assess its extent.
[Recommendations based on very low to high certainty diagnostic evidence]
Ensure that specialist transvaginal ultrasound scans and pelvic MRI scans are planned and interpreted by a healthcare professional with specialist expertise in gynaecological imaging.
[Recommendation based on the GC’s experience]
Implementation
The updated recommendation on ultrasound will likely lead to increased use of transvaginal ultrasound offered in primary care; however, this may reduce the need for a transvaginal ultrasound scan after referral to gynaecology services for some. Additional training of sonographers will be required to enhance sonographers’ competencies in detecting features associated with endometriosis.
Referral recommendations that have been upgraded to “refer” from “consider referring” are likely to lead to more people being referred to secondary and tertiary care services. However, earlier referral of people subsequently diagnosed with endometriosis is likely to lead to treatment being started earlier, and may lead to a reduction in end organ damage owing to the disease. Although a cost effectiveness analysis has not been formally performed, the guideline committee thought earlier referral may lead to a subsequent decrease in cost of overall treatment.
Guidelines into practice
How do you assess a person with suspected endometriosis?
What factors do you use to decide if a patient needs referral to gynaecology or a specialist endometriosis service?
Further information on the guidance
This guidance was developed by NICE in accordance with NICE guideline methodology (www.nice.org.uk/media/default/about/what-we-do/ourprogrammes/developing-nice-guidelines-the-manual.pdf). A guideline committee (GC) was established by NICE, which incorporated an independent chair, a topic adviser (consultant in obstetrics and gynaecology), and healthcare and allied healthcare professionals (one clinical nurse specialist, one consultant gynaecologist, one consultant surgeon, one consultant clinical psychologist, one GP with an interest in maternity care, one consultant obstetrician and gynaecologist, and one pharmacist) and three lay members. The guideline is available at https://www.nice.org.uk/guidance/ng73. The GC identified relevant review questions and collected and appraised clinical and cost effectiveness evidence. Quality ratings of the evidence were based on GRADE methodology (www.gradeworkinggroup.org). These relate to the quality of the available evidence for assessed outcomes rather than the quality of the study. The GC agreed recommendations for clinical practice based on the available evidence or, when evidence was not found, based on their experience and opinion using informal consensus methods. The draft of the guideline went through a rigorous reviewing process, in which stakeholder organisations were invited to comment; the GC took all comments into consideration when producing the final version of the guideline. NICE will conduct regular reviews after publication of the guidance, to determine whether the evidence base has progressed significantly enough to alter the current guideline recommendations and require an update.
How patients were involved in the creation of this article
Anna Cooper, Emma Cox, and Sunaina Nechel-Maher are lay members of the guideline committee and contributed to the formulation of the recommendations summarised in this article. All were involved in the development and reviewing of this article, to ensure lay and patient perspectives were considered and included.
Acknowledgments
The members of the Guideline Committee were (shown alphabetically): Alena Chong, Anna Cooper, Ashifa Trivedi, Bryony Kendall, Chimwemwe Kalumbi, Christian Becker, Claudia Tye, Emma Cox, Emma Evans, Lucky Saraswat, Sarah Fishburn, Sunaina Nechel-Maher, Thomas Smith Walker.
The members of the NICE technical team were (shown alphabetically): Agnesa Mehmeti (technical analyst), Clifford Middleton (quality and engagement manager), Hayley Jones (project manager), Hilary Eadon (topic lead till July 2024), Maija Kallioinen (topic lead from July 2024), Paul Jacklin (health economics adviser), Sharangini Rajesh (senior technical analyst), Stephanie Arnold (senior information specialist).
Footnotes
The full version of this guideline is available at https://www.nice.org.uk/guidance/ng73.
Funding: No authors received specific funding to write this summary.
Competing interests: We declared the following interests based on NICE’s policy on conflicts of interests (https://www.nice.org.uk/Media/Default/About/Who-we-are/Policies-and-procedures/declaration-of-interests-policy.pdf):
The guideline authors’ full statements can be viewed at https://www.nice.org.uk/guidance/ng73.
Contributorship and the guarantor: All four authors confirm that they meet all four authorship criteria in the ICMJE Uniform requirements. SR is the guarantor for this article. The views expressed in this publication are those of the authors and not necessarily those of NICE.
Provenance and peer review: commissioned; not externally peer reviewed.