Adenomyosis is a disease where ectopic endometrial glands affect the muscular wall of the uterus. Women that suffer from dysmenorrhea or infertility caused by adenomyosis need to confirm or rule out adenomyosis, and therefore tools for non-histologic confirmation of adenomyosis are indubitably required. Transvaginal ultrasound has been shown to be useful in diagnosing adenomyosis, but the interpretation of findings requires significant expertise in ultrasound and experience with diagnosing adenomyosis. This is because adenomyosis shows a very heterogeneous appearance in ultrasound. There are many different diagnostic signs that have to be considered and weighed.

In a previous study, the investigators have developed a diagnostic algorithm that helps clinicians diagnose adenomyosis with transvaginal ultrasound and a clinical examination. It showed good diagnostic accuracy and seemed to be very robust with regards to artifacts and experience of the examiner. It is now necessary to validate this prediction model in a new, prospective study so it can be used in clinical practice.

Inclusion Criteria:

• Premenopausal (defined by having had menstruation the last six month)
• If amenorrhea with levonorgestrel intrauterine device, the woman should be < 45 years old
• Hysterectomy planned due to a benign condition
• Hysterectomy does not require morcellation it is allowed to divide the uterus into 2-3 pieces, given that the orientation of the specimen is still possible for the pathologist)
• Written consent is given
• Can communicate in Norwegian or English at the Norwegian study sites, and Finnish, Swedish or English at the Finnish study site.

Exclusion Criteria:

• Gynecological cancer present at the time of inclusion
• Use of gonadotropin-releasing hormone agonist or antagonist within the last 3 months prior to the ultrasound evaluation
• Prior endometrial ablation or resection
• Postmenopausal status or no menstrual bleeding for the last 6 months, or amenorrhea with levonorgestrel-intrauterine device and age >45 years.
• Need for morcellation of the uterus

A consecutive sample of women that are scheduled for a hysterectomy at one of the study sites and fulfill eligibility criteria are invited to participate.

We will share the values of all evaluated predictors in the model so that they can be used for re-calculation.

The data is planned to be made available within a year after the publication of all results.

Access will be granted upon request and evaluation of the intended use of the data. The intended use should primarily gain improved patient care and research into adenomyosis and a detailed protocol has to be submitted.