Endometriosis and adenomyosis are distinct conditions that can significantly impact fertility; while adenomyosis involves tissue displacing into the muscular wall of the uterus, endometriosis is a systemic, full-body condition involving tissue similar to the womb lining growing outside of the uterus entirely. Sadly, both conditions often go undiagnosed for a long time.

What are these conditions and how can they impact fertility? Here we break it down.

Endometriosis and adenomyosis: What are they?

The inner lining of tissue in the womb is known as the endometrium. Every month, this lining thickens and regenerates in preparation for conception. But if there is no pregnancy, once a month the uterus sheds this lining and a woman menstruates.

While endometriosis and adenomyosis both involve abnormal tissue growth, they behave very differently. Adenomyosis specifically involves the inner lining of the womb (the endometrium) growing into places it is not supposed to be within the uterus. Endometriosis, conversely, involves tissue similar to the endometrium growing entirely outside of the uterine cavity.

In endometriosis, this tissue – which behaves much like the womb lining but is a distinct, similar tissue type – grows outside of the womb as a chronic, systemic condition. It commonly develops on pelvic organs such as the fallopian tubes, ovaries, or bladder, and can also impact other systems throughout the body. Because of the widespread inflammation it causes, endometriosis can make it difficult to fall pregnant.

With adenomyosis, actual endometrial tissue grows directly into the muscular wall of the womb (the myometrium), thickening the uterine wall and distorting local blood vessels. This localised disruption can create heavy, extended and very painful menstruation. It may also lead to pain during intercourse and is frequently associated with fertility and implantation problems. Unlike endometriosis, the tissue in adenomyosis remains contained within the structure of the uterus and does not breach the outer uterine wall.

How can endometriosis affect fertility?

Many women with endometriosis can get pregnant. But in up to half of all cases, there will be problems with fertility.

There is no sole definitive answer as to how endometriosis causes infertility, but possible reasons include:

• Endometriosis can create scarring, making it hard for an egg to pass down the fallopian tube properly.
  Both the endometriosis itself and its resulting scarring can change the ‘terrain’ of a woman’s reproductive organs and pelvis, making it trickier for the egg and sperm to make contact.
• Endometriosis is sometimes associated with an irregular immune response to the embryo.
  Endometriosis can generate a release of chemicals (Cytokines and others) that make the pelvic fluid hostile for gametes and embryos.
• Endometriosis can be associated with faulty progesterone receptors that might affect embryo implantation and early pregnancy.
• For women with endometriosis, the uterine environment is sometimes not sufficiently developed to support a pregnancy through to term.

If you need to know more, we covered endometriosis and fertility in more detail in our blog post ‘How can I increase my fertility with endometriosis?’

Is adenomyosis a type of endometriosis?

No. Endometriosis and adenomyosis are similar but distinct disorders. They have some symptoms in common but they affect separate parts of the body. They may need different healthcare interventions.

However, some women do have both endometriosis and adenomyosis at once.

What are the symptoms of adenomyosis?

Adenomyosis is sometimes called a ‘silent’ illness because it may go undiagnosed for a long time. Sometimes it may cause no symptoms or very little discomfort. However adenomyosis may present with:

• Extended or heavy menstrual bleeding
• Severe menstrual cramps or sharp pelvic pain during your period
• Recurring pelvic pain
• Pain during sexual intercourse
• Pressure or sensitivity around your lower abdomen (due to an enlarged womb)

Is adenomyosis a serious condition?

Thankfully, adenomyosis is not a life-threatening condition. However the pain, heavy bleeding and possible complications of adenomyosis may affect a woman’s quality of life and create a lot of stress.

What happens if adenomyosis is left untreated?

Adenomyosis is generally a progressive condition, meaning it may get worse over time if left untreated. For example, pain may become more severe and frequent.