Adenomyosis: symptoms, diagnosis and treatments

What is adenomyosis?

The wall of the uterus has two main layers: the endometrium, the inner lining that renews itself with each cycle, and the myometrium, the thick muscular layer. Between the two lies a transition area called the junctional zone.

In adenomyosis, glands and supporting tissue from the endometrium penetrate into the myometrium. This tissue responds to hormones and causes inflammation and thickening of the surrounding muscle. The uterus may enlarge and become more globular.

A distinction is made between:

• diffuse adenomyosis, spread across a large part of the uterine wall;
• focal adenomyosis, limited to one area; when it forms a clearly visible mass, it is called an adenomyoma, which can look like a fibroid.

Adenomyosis is often associated with endometriosis (lesions located outside the uterus) and with fibroids. They are, however, distinct conditions, with partly different treatments.

What are the symptoms of adenomyosis?

Symptoms are varied and not very specific:

• heavy periods, sometimes with clots, which can lead to anaemia (iron deficiency, tiredness, breathlessness);
• painful periods, often appearing or worsening over time;
• chronic pelvic pain or pain during intercourse;
• bleeding between periods;
• difficulty getting pregnant or miscarriages.

Some women have no symptoms at all: adenomyosis is then discovered on an ultrasound performed for another reason. Adenomyosis without symptoms and without plans for pregnancy does not require treatment.

Historically, adenomyosis was described in women over 40 who had had children. Thanks to imaging, we now know that it also affects young women, including those who have never been pregnant.

How is the diagnosis made?

Gynaecological examination may find an enlarged, globular, sometimes tender uterus. The diagnosis relies on imaging, interpreted together with the symptoms and the examination.

Transvaginal ultrasound

This is the first-line examination. In 2022, a group of European experts revised the MUSA (Morphological Uterus Sonographic Assessment) criteria, which distinguish:

• direct signs, showing endometrial tissue within the muscle: small cysts in the myometrium, hyperechoic (brighter) islands, fine lines or buds extending from the endometrium;
• indirect signs, reflecting the reaction of the muscle: globular uterus, asymmetrical thickening of the walls, fan-shaped shadowing, vessels crossing the lesion, irregular or interrupted junctional zone.

3D ultrasound gives a better view of the junctional zone.

Pelvic MRI

MRI is useful when there is doubt, a large uterus, associated fibroids, or to look for associated endometriosis. It analyses the thickness of the junctional zone: clear thickening points towards adenomyosis. It also better distinguishes an adenomyoma from a fibroid.

When periods are heavy, the work-up also looks for other causes: endometrial polyp, fibroid, clotting disorder, hormonal abnormality. A blood test assesses anaemia and iron stores.

What are the medical treatments?

Treatment depends on symptoms, age and plans for pregnancy. There is no medicine specific to adenomyosis: the treatments used are similar to those for endometriosis.

• The 52 mg levonorgestrel hormonal IUD (intrauterine device): it reduces heavy bleeding and pain, with a local action. It is often the first treatment offered to women with no immediate plans for pregnancy. The 2022 French CNGOF guidelines on abnormal uterine bleeding include a chapter on adenomyosis.
• Continuous progestogens (dienogest, desogestrel): they put the lining at rest and reduce periods.
• The combined oestrogen-progestogen pill taken continuously: it reduces pain and bleeding.
• Non-hormonal treatments during periods: tranexamic acid reduces heavy bleeding; anti-inflammatories reduce pain and, to a lesser extent, bleeding.
• GnRH agonists: they temporarily reduce the size of the uterus and the symptoms, but their side effects limit how long they can be used; they are sometimes used before surgery or IVF.
• Correction of anaemia with iron, as tablets or by infusion.

The details of these treatments are covered in the article Endometriosis: hormonal treatments and pain relief.

When is surgery considered?

Hysterectomy

Removal of the uterus is the only definitive treatment for adenomyosis. It is offered when medical treatments have failed or are not tolerated, in a woman who no longer plans a pregnancy. It is most often performed by laparoscopy or vaginally. The ovaries can usually be preserved. Surgical approaches and recovery are detailed in the article Hysterectomy.

Conservative treatments

For women who wish to keep their uterus, other options exist, though they have been less fully evaluated:

• removal of an adenomyoma (adenomyomectomy), mainly for a focal form, with a risk to the strength of the uterine wall in a later pregnancy;
• uterine artery embolisation, performed by an interventional radiologist;
• heat-based destruction techniques (focused ultrasound, radiofrequency), still not widely available in France;
• hysteroscopic endometrial ablation, which may be considered for some women with no plans for pregnancy, with poorer results in deep adenomyosis.

Does adenomyosis affect fertility and pregnancy?

Adenomyosis is found more often in women seeking help for infertility. It may hinder embryo implantation and increase the risk of miscarriage, but studies are heterogeneous. In IVF, hormonal suppression with GnRH agonists before a frozen embryo transfer is sometimes offered; its value is discussed case by case with the medically assisted reproduction centre.

During pregnancy, a meta-analysis of 39 studies published in 2025 in the American Journal of Obstetrics and Gynecology links adenomyosis with an increase in certain risks: pre-eclampsia, preterm birth, low birth weight, haemorrhage after birth, abnormal placental position, miscarriage. The level of evidence is low; the authors recommend tailored antenatal monitoring: tell the team looking after your pregnancy that you have adenomyosis.

Frequently asked questions

General information article: it does not replace a medical consultation. In an emergency, call 15 or 112 in France, or your local emergency number.