What is Adenomyosis? Risks, Symptoms and Treatment

By MD, MSc (gynecologist), BSc, MSc (embryologist) and (invitra staff).
Last Update: 01/20/2020

Adenomyosis, also known as internal endometriosis, is a uterine condition in which tissue from the inner layer of the uterus (endometrium) is found in the muscular layer of the uterus (myometrium). It can increase the risk of infertility and its treatment will depend on the woman's symptoms and whether or not she intends to get pregnant.

Definition of Endometrium and Myometrium

To understand what adenomyosis is, it is important to know that the uterus consists of two layers.

The endometrium is the innermost layer of this organ and covers the surface of the uterine cavity. It is highly vascularized (that is, it has many blood vessels), because it is the part that prepares each menstrual cycle for the embryo to implant and form the placenta in the event of a pregnancy. If pregnancy doesn’t happen, the layer comes off and causes menstruation.

You can learn more about the characteristics of this layer at the following link: What is the endometrium?

On the other hand, the myometrium is the muscular layer of the uterus and is responsible for uterine contractions during childbirth. This layer is closely related to the endometrium, but it must be well defined, otherwise it can lead to problems.

What is internal endometriosis?

Internal endometriosis or adenomyosis is the presence of endometrial tissue in the myometrium. Sometimes this tissue can cause a mass or tumor inside the uterus, which is called adenomyoma.

Two types can be found:

Focal or localized adenomyosis
with adenomyomas, also called Cullen's adenomyosis.
Diffuse Adenomyosis
distributed over much of the myometrium, which causes the uterus to increase in size. It's the most common form.

Depending on the location of the endometrial tissue in the myometrium, we also distinguish between superficial and deep adenomyosis.

This disease is more common in women in their 40s and 50s who have been mothers, but it can also occur in younger patients without children.

Causes and symptoms

The causes of this affectation are not yet clearly known. It is known to be estrogen-dependent and, among the factors that predispose it to develop, we find having had at least one pregnancy and previous uterine surgeries (cesarean sections, curettages, hysteroscopies...).

All these situations have in common that the barrier between the endometrium and myometrium can be broken. Some theories also argue that it is attributed to alterations in the embryonic development of the woman's reproductive system.

About two-thirds of women with adenomyosis have some type of symptom. The following symptoms are the most frequent:

  • Menstrual pain (dysmenorrhea)
  • Menstrual periods that are too long or too heavy (menorrhagia)
  • Pain during sex (dyspareunia).
  • Irregular bleeding (metrorrhagia).
  • Anemia caused by heavy bleeding.
  • Lower back pain.

Because these symptoms depend on estrogen levels, they will improve with the onset of menopause.


Clinical diagnosis of this pathology is difficult, because its symptoms are non-specific and it often coexists with other pelvic diseases. This has resulted, until recently, in under-diagnosis.

Thanks to the technical improvement of ultrasound devices and a greater awareness of their existence by specialists, more and better diagnoses are being made nowadays.

To make a diagnosis, besides taking into account the patient's medical history, the following exams are carried out:

  • Pelvic exam: To detect if the uterus is enlarged.
  • Transvaginal ultrasound: it is cheap, simple and painless. It allows an efficient diagnosis of adenomyosis.
  • Magnetic resonance imaging (MRI): may be useful when we do not have enough information obtained through ultrasound, which occurs mostly in patients with fibroids.
  • Other less common diagnostic methods that may be useful: hysteroscopy, hysterosalpingography, endometrial biopsy.

The only technique that allows a definitive diagnosis is the histopathological study of the uterus after a hysterectomy (partial or total removal of the uterus).

Treatment and possible complications

Treatment for adenomyosis should be individualized and will depend mainly on the severity of the symptoms (mild, moderate, severe), desire to get pregant and the patient’s age.

At first, priority is given to relief symptoms through pharmacological methods. For this purpose, following drugs will be administered:

  • Analgesics (non-steroidal anti-inflammatory drugs)
  • Hormonal contraceptives
  • Danazol (antiestrogens)
  • Gonadotropin-releasing hormone (GnRH) analogues

In most patients, these treatments are enough to end the symptoms of the disease. However, many of them are incompatible with pregnancy.

If pharmacological methods fail or the patient wants to get pregnant, depending on the size and extent of the lesions, surgical treatment may be indicated. It consists of removing the adenomiotic tissue and reconstructing the uterine wall. If symptoms do not disappear with these methods, the only treatment that is totally effective in ending deep adenomyosis is to surgically remove the uterus (hysterectomy). Before making this decision, it will be necessary to assess if the patient intends to get pregnant and whether menopause is near, since as we have mentioned, the symptoms disappear after menopause.

Consequences on fertility and pregnancy

Adenomyosis can have a negative effect on fertility, as some studies have shown that it decreases pregnancy rates and increases abortion rates. Implantation failures also happen more frequently.

Several mechanism have been found which may affect:

  • Genetic regulation.
  • Uterine movements (Peristalsis)
  • Endometrial receptivity and implantation.

Adenomyosis can also make it difficult to transport the gametes, which is necessary for them to meet and fertilize. In addition, it can affect the transport of the embryo to the implantation site and complicate the arrival of nutrients and oxygen.

In vitro fertilization (IVF) treatments can address some of these limitations and help patients with adenomyosis achieve pregnancy.

In cases where a hysterectomy has been chosen and the woman wishes to become a mother, she may resort to adoption or surrogacy.

FAQs from users

Can obesity influence adenomyosis?

By Ana Mª Villaquirán Villalba MD, MSc (gynecologist).

Adenomyosis, also known as internal endometriosis, is a uterine condition in which there is tissue from the inner layer of the uterus (endometrium) in the muscular layer of the uterus (myometrium). The causes of this condition are not clearly known, although it is known to be estrogen-dependent and, among the factors that predispose it to develop, we find having had at least one pregnancy and previous uterine surgeries (cesarean sections, curettage, hysteroscopies, etc.).

It is also very much related to age, especially after 40 years of age. That is why in some cases it is colloquially called uterine aging.

Certain adenomioses are only detected by special techniques such as a 4D ultrasound or a magnetic resonance imaging. For mild cases, there are very few treatments with apparent effectiveness and it is not fully demonstrated that they have a negative effect on patients' pregnancy rates. However, severe cases such as T-uteruses require corrective surgery through hysteroscopy.

Does adenomyosis produce cancer?

By Rebeca Reus BSc, MSc (embryologist).

No evidence has been found that adenomyosis causes cancer. However, some symptoms of adenomyosis may be linked to some cancers, such as uterine bleeding.

Can women who haven't had children have adenomyosis?

By Rebeca Reus BSc, MSc (embryologist).

This disorder is more common in women aged 40-50 who have already given birth, but it can also occur in younger women who have not yet become mothers.

Can I become egg donor if I have adenomyosis?

By Rebeca Reus BSc, MSc (embryologist).

Each case has to be assessed individually. It must be taken into account that some of the symptomatic treatments for adenomyosis are hormonal and can complicate obtaining the eggs.

You'll find more information about the egg donation process here: How can I become an egg donor?

Is uterine myoma (fibroids) the same as adenomyosis?

By Rebeca Reus BSc, MSc (embryologist).

No. In the case of uterine myomatosis, fibroids, that is, tumors of muscle tissue, form. Adenomyosis, on the other hand, is the presence of endometrial tissue in the myometrium. They only coincide in location: the myometrium, the muscular layer of the uterus.

Is endometriosis the same as adenomyosis?

By Rebeca Reus BSc, MSc (embryologist).

Both pathologies consist of the presence of ectopic endometrial tissue, that is, outside its physiological location: the endometrium.

However, a distinction must be made between internal endometriosis or adenomyosis and external endometriosis. In the former, the endometrial tissue is found in the myometrium. In the second, it can appear in any organ of the body other than the uterus.

Generally, when we refer only to endometriosis, we are talking about external endometriosis.

On the other hand, it is also important to note that, although they are not exactly the same pathology, some women can present both at the same time.

Suggested for you

Adenomyosis is classified as a uterine disorder that may affect fertility. In this article you will find more information about this type of pathology and its influence on sterility: Uterine Factor female infertility.

If you want to know more about fibroids, we recommend you follow this link: What are fibroids?

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.


Authors and contributors

 Ana Mª Villaquirán Villalba
Ana Mª Villaquirán Villalba
Bachelor's Degree in Medicine from the University of Valle, Colombia. Specialist in Obstetrics & Gynecology. Master's Degree in Human Reproduction from the University of Valencia and IVI. Currently, she is the medical director of Tahe Fertilidad. More information about Ana Mª Villaquirán Villalba
License: 303007571
 Rebeca Reus
Rebeca Reus
BSc, MSc
Degree in Human Biology (Biochemistry) from the Pompeu Fabra University (UPF). Official Master's Degree in Clinical Analysis Laboratory from the UPF and Master’s Degree about the Theoretical Basis and Laboratory Procedures in Assisted Reproduction from the University of Valencia (UV). More information about Rebeca Reus
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

Find the latest news on assisted reproduction in our channels.