What is endometriosis?

The medical term for the lining of the womb (uterus) is the endometrium. The cells that make up the endometrium are responsive to the hormonal changes that occur throughout the menstrual cycle. These changes cause the lining of the womb to thicken in preparation for a fertilised egg. If fertilisation does not occur the lining is then shed in the form of a monthly period.

In women with endometriosis, some of the specialised cells that make up the endometrium are also found outside the womb. The cells outside the womb react to hormonal changes in the same way as those inside the womb. However, when the cells outside the womb break down and bleed they remain inside the body, where they can cause considerable pain and discomfort. They can also cause the formation of scar tissue.

The severity of endometriosis varies depending on where the extra cells occur. The cells can grow anywhere in the body but are usually found within the pelvis, for example, within the fallopian tubes, ovaries, bladder or bowel.

It is estimated that endometriosis affects one in 10 women in the UK.

What causes endometriosis?

It is not known what causes the growth of the extra endometrial cells, and currently there is no cure for the condition. However, there are a number of treatments available that can help manage the symptoms.

What are the symptoms of endometriosis?

Severe pain may be experienced during periods as a result of bleeding outside the womb. Pain may also be experienced at the time of ovulation or during sexual intercourse. Periods may be heavy (sometimes with clots) or prolonged. Endometriosis may cause the fallopian tubes to become blocked - this can prevent the passage of eggs from the ovaries leading to fertility problems. Endometriosis is often diagnosed during investigations into infertility.

Are any tests necessary?

Endometriosis is usually diagnosed using a procedure called a laparoscopy. This is a minor operation which may be carried out as day surgery. A laparoscope, a small fibre-optic tube which relays images to a video camera, is passed in to the pelvis via a tiny incision at the navel. This enables the doctor to view inside the pelvis and look for the presence of the specialised cells.

What treatment is available?

There are two main forms of treatment available: surgery and drug therapy. The most appropriate method will be chosen according to the severity and location of the endometriosis.

Surgery can be performed to remove areas of endometriosis and if very badly affected, parts of the reproductive organs. However, decisions about the extent of the surgery will depend on whether a woman wishes to conceive in the future. Surgery may also help if the endometriosis is causing fertility problems.

The most common form of treatment is drug therapy. There are a number of drugs that can be prescribed and the doctor will choose one according to each individual and her situation. If one drug is not well tolerated, another can be prescribed.

A group of drugs called GnRH analogues may be used to treat endometriosis. These drugs work by decreasing the activity of the ovaries, leading to inhibition of endometrial growth. Drugs in this group include buserelin (Suprecur®), goserelin (Zoladex®), leuprorelin (Prostap® SRDCS, Prostap 3®DCS), nafarelin (Synarel®) and triptorelin (Decapeptyl® SR, Gonapeptyl®).

GnRH analogues can cause side effects similar to the symptoms experienced during the menopause. They are often prescribed to reduce the number and size of endometrial lesions and may also be given to thin the endometrium prior to surgery.

Danazol (eg, Danol®) is a gonadotrophin release inhibitor that has similar effects to testosterone and also decreases ovarian activity. It is important that pregnancy does not occur during treatment with GnRH analogues or danazol; therefore, women must use a barrier method of contraception during treatment.

Progestogens such as medroxyprogesterone (eg, Climanor®, Provera®) and norethisterone (eg, Primolut® N, Utovlan®) suppress ovulation but normal ovulatory cycles can return two months after treatment is stopped. They are therefore useful for women who wish to conceive after treatment.

The combined oral contraceptive pill may also help in decreasing the severity of endometriosis.

Pain medication such as ibuprofen or other non-steroidal anti-inflammatory drugs may also be used.

Further information available from:

Endometriosis UK
Suites 1 & 2
46 Manchester Street
London W1U 7LS
Tel: 020 7222 2781
Helpline: 0808 808 2227
Internet: www.endometriosis-uk.org

Fact sheet provided by MIMS

Date last reviewed: September 2014

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