Fibroids

Page last reviewed: 13/07/2011

Fibroids are benign (non-cancerous) tumours that grow in or around the womb (uterus). The growths are made up of muscle and fibrous tissue and can vary in size. Fibroids are sometimes known as uterine myomas or fibromyomas.

Fibroids usually develop during a woman's reproductive years (from approximately 16 to 50 years of age). They are linked to the production of oestrogen, which is the female reproductive hormone.

Types of fibroids

Fibroids can grow anywhere in the womb. The five main types of fibroids are described below.

  • Intramural fibroids develop in the muscle wall of the womb and they are the most common type of fibroids found in women.
  • Subserosal fibroids grow outside the wall of the womb into the pelvis and can become very large.
  • Submucosal fibroids develop in the muscle beneath the inner lining of the womb wall and they grow into the middle of the womb.
  • Pedunculated fibroids grow from the outside wall of the womb and are attached to the womb wall by a narrow stalk.
  • Cervical fibroids develop in the wall of the cervix (the neck of the womb).

How common are fibroids?

Fibroids are common, with at least one in four women developing them at some stage in their life. They most often occur in women who are from 30 to 50 years old.

Fibroids tend to develop more frequently in women who are of Afro-Caribbean origin and in women who are overweight. It is thought that they occur in heavier women as a result of higher oestrogen levels.

Outlook

In many cases, fibroids do not cause symptoms and treatment is not required. Over time, fibroids will often shrink and disappear without any treatment.

However, sometimes fibroids can cause symptoms, such as pain or heavy bleeding. In such cases, medication may be prescribed. If this proves ineffective, surgical or non-surgical techniques may be recommended.

Benign

Benign refers to a condition that should not become life-threatening. In relation to tumours, benign means not cancerous.

Womb

The uterus (also known as the womb) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.

Tissue

Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.

Cervix

The cervix is at the lower end of the womb. It connects the womb with the vagina.

Malignant

Malignant is a term used to describe a life-threatening or worsening condition. In the case of tumours, malignant means cancerous.

Page last reviewed: 13/07/2011

Many women are unaware they have fibroids because they do not have any symptoms. If your fibroids do cause symptoms, you may experience one or more of the following:

Heavy or painful periods

Fibroids do not disrupt the normal menstrual cycle (periods) but they can cause heavy or painful bleeding. Heavy bleeding can some-times cause anaemia (a reduction of oxygen-carrying red blood cells). See the Complications section for more information.

Abdominal pain

If you have fibroids, particularly if you have large ones, you may experience discomfort or bloating (swelling) in your stomach. You may also experience pain in your back and legs.

Frequent urination and constipation

If your fibroids press on your bladder, you may need to urinate frequently. Fibroids can also press on your rectum (large intestine), which can cause constipation.

Pain or discomfort during sex

If you have fibroids growing near to your vagina, or cervix (neck of the womb), you may experience pain or discomfort during sexual intercourse (dyspareunia).

Glossary

Bladder
The bladder is a small organ near the pelvis that holds urine until it is ready to be passed from the body.

Fibroids are growths of smooth muscle and fibrous tissue in the womb. 

Page last reviewed: 13/07/2011

The exact cause of fibroids is unknown. However, fibroids are linked to the female hormone, oestrogen. Oestrogen is the female reproductive hormone produced by the ovaries (the female reproductive organs).

Fibroids tend to increase in size when oestrogen levels are at their highest, such as during pregnancy. They are also known to shrink when oestrogen levels are low, such as after the menopause (when a woman's monthly periods stop at around 50 years of age). 

Page last reviewed: 13/07/2011

As fibroids do not often cause symptoms, they are sometimes discovered during a routine gynaecological (vaginal) examination or during a diagnostic test or scan. A diagnostic test is any test that is carried out to help confirm or rule out a health condition that may be causing your symptoms.

If your GP suspects fibroids, they may recommend that you have some tests to confirm a diagnosis, or to rule out other possible causes of your symptoms. These tests are listed below.

Ultrasound scan

An ultrasound scan of the womb is often used to confirm a diagnosis of fibroids. It can also be used to rule out any other possible causes of your symptoms.

Depending on the results of your ultrasound scan, your GP may refer you to a gynaecologist (a specialist in the female reproductive system). The gynaecologist will be able to investigate the problem further using a number of specialised techniques, such as those outlined below.

Trans-vaginal scan

A trans-vaginal scan is sometimes used to diagnose fibroids. It involves inserting a small scanner into your vagina to take a close-up image of your womb.

Hysteroscope

It may be possible to see fibroids that are near your inner lining (intramural fibroids), and those within the cavity of your womb (submucosal fibroids) using a hysteroscope. A hysteroscope is a small telescope used to examine the inside of your womb.

Laparoscope

A laparoscope is a thin, flexible microscope with a light on the end that is used to look inside the stomach. It can also be used to examine the size and shape of the outside of your womb.

Biopsy

laparoscopy can also be used to take a biopsy (a tissue sample) of the inside lining or the outer layer of your womb. The sample can then be sent to a laboratory for closer examination under a microscope.


Glossary

Womb
The uterus (also known as the womb) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.
Ultrasound scan

Page last reviewed: 13/07/2011

Treatment for fibroids may not be necessary in cases where they do not cause symptoms, or where symptoms are minor.

For example, if you have heavy periods, you may choose not to have treatment because your day-to-day life is not significantly affected. After the menopause, fibroids often shrink, and it is likely your symptoms will either ease slightly or disappear completely.

To treat fibroids, your GP may recommend medication. However, in more severe cases, a number of surgical techniques may be considered. You should visit your GP to discuss the best treatment plan for you.

Medication

Gonadotropin releasing hormone agonist (GnRHa)

GnRHa is a hormone that is often recommended to treat fibroids. GnRHa is given by injection and works by making your body release a small amount of oestrogen, which causes your fibroids to shrink.

GnRHa stops your menstrual cycle (period) but it is not a form of contraception. It does not affect your chances of becoming pregnant after you stop using it. 

If you are prescribed GnRHa, it can help to ease heavy periods and any pressure that is felt on your stomach. It can also help to improve symptoms of frequent urination and constipation.

GnRHa can cause a number of menopause-like side effects including:

  • hot flushes,
  • increased sweating,
  • muscle stiffness, and
  • vaginal dryness.

Sometimes, osteoporosis (thinning of the bones) is a side effect of GnRHa. Your GP will be able to give you more information about this and may prescribe additional medication to minimise thinning of your bones.

GnRHa is only prescribed on a short-term basis and after treatment is stopped, your fibroids may return.

GnRHa can also be used to shrink fibroids prior to having surgery to remove them. Sometimes, a combination of GnRHa and low doses of hormone replacement therapy (HRT) may be recommended to shrink your fibroids, while preventing the side effects of the menopause.

Other medicines

There are other medicines available that can be used to treat heavy periods, but they can to be less effective the larger your fibroids are. These medications are described below.

Tranexamic acid

Tranexamic acid tablets are taken three to four times a day throughout your period. The tablets work by helping the blood in your womb to clot, which reduces the amount of bleeding.

Tranexamic acid tablets are not a form of contraception and will not affect your chances of becoming pregnant once you stop taking them. Treatment should be stopped if your symptoms have not improved within three months.

Anti-inflammatory medicines

Anti-inflammatory medicines, such as ibuprofen and mefanamic acid, are taken for a few days during your period and will help ease your heavy bleeding. They work by reducing your body's production of a hormone-like substance called prostaglandin, which is linked to heavy periods.

Anti-inflammatory medicines are also painkillers, but they are not a form of contraception. Indigestion and diarrhoea are common side effects.

The contraceptive pill

The contraceptive pill is a popular form of contraception that stops an egg from being released from the ovaries to prevent pregnancy. As well as making bleeding lighter, some contraceptive pills can help to reduce period pain. Your GP will be able to provide you with further advice about contraception and the contraceptive pill.

Levonorgestrel intrauterine system (LNG-IUS)

LNG-IUS is a small, plastic device that is placed in your womb and slowly releases the progestogen hormone called levonorgestrel. LNG-IUS stops the lining of your womb from growing quickly, so that it is thinner and your bleeding becomes lighter.

Side effects associated with LNG-IUS include:

  • irregular bleeding that may last for more than six months,
  • acne (inflamed skin on the face),
  • headaches, and
  • breast tenderness.

In rare cases, LNG-IUS may also stop you having periods at all.

Surgery

Surgery may be considered if your fibroid symptoms are particularly severe and all forms of medication have proved ineffective.

There are a number of different surgical procedures used to treat fibroids. Your GP will refer you to a specialist who will be able to discuss all the options with you, including the benefits and any associated risks.

Some of these surgical procedures are explained below.

Hysterectomy

hysterectomy is a surgical procedure to remove the womb. It may be recommended if you have large fibroids or severe bleeding.

A hysterectomy is the best way of preventing fibroids re-occurring. You may want to consider it if you have fibroids that are particularly troublesome and you do not wish to have any more children.

Side effects of a hysterectomy include the possibility of early menopause, and some women have a reduction in their libido (sex drive).

Myomectomy

A myomectomy is a surgical procedure to remove the fibroids from the wall of your womb. It may be considered as an alternative to a hysterectomy, particularly for women who still wish to have children.

A myomectomy involves making a small incision (cut) in your stomach through which your fibroids are removed. This type of surgery is commonly known as keyhole surgery.

A myomectomy may not always be possible as it depends on your individual circumstances, such as the size, number and position of your fibroids.

Non-surgical treatments

As well as using traditional surgical techniques to treat fibroids, there are also non-surgical treatments available. These are outlined below.

Endometrial ablation

Like a myomectomy, endometrial ablation is an alternative to having a hysterectomy and involves removing the lining of the womb. It is usually only recommended for fibroids that are near to the inner surface of the womb.

The affected womb lining can be removed in a number of ways, e.g. by using laser energy, a heated wire loop, microwave heating or hot fluid in a balloon.

Uterine artery embolisation (UAE)

UAE is an alternative procedure to a hysterectomy and myomectomy for treating fibroids. It may be recommended for women with large fibroids.

UAE is performed by a radiologist (a doctor who has been trained to interpret X-rays and scans). It works by blocking the blood vessels that supply blood to the fibroids, causing them to shrink.

During the procedure, a chemical is injected through a small tube (catheter), which is guided by X-ray through a blood vessel in your leg. It is carried out under local anaesthetic, which means you will be awake but the area being treated will be numbed.

Following a UAE, you will need to stay in hospital for 24 to 36 hours. When you leave hospital, you will be advised to rest for one to two weeks.

Glossary

Womb
The uterus (also known as the womb) is a hollow, pear-shaped organ in a woman where a baby grows during pregnancy.
Hysterectomy
A hysterectomy is surgery to remove the uterus (womb), cervix and sometimes the fallopian tubes and ovaries.

Page last reviewed: 13/07/2011

Most women with fibroids do not have any problems. However, in some cases, fibroids can cause significant problems.

Complications can occur as a result of the positioning of fibroids, and in cases where they are very large. Some possible complications are outlined below.

Heavy periods

If you have heavy periods (menorrhagia), it does not necessarily mean that there is anything seriously wrong. However, it can have a significant impact on your everyday life and lead to anxiety and depression.

In some cases, menorrhagia can cause iron-deficiency anaemia, resulting in symptoms such as tiredness, lethargy and shortness of breath (dyspnoea).

Pregnancy

During pregnancy, levels of the female reproductive hormone, oestrogen, can increase by as much as five times the normal amount. As fibroids are thought to develop due to high oestrogen levels, it may lead to complications with the development of the baby, or cause problems during labour.

In very rare cases, fibroids can cause miscarriage (the loss of pregnancy during the first 23 weeks). Your GP or midwife will be able to give you further information and advice if you have fibroids and you are pregnant.

Infertility

Infertility (the inability to become pregnant) may occur in cases where a woman's fibroids are very large. Large fibroids can sometimes prevent a fertilised egg attaching itself to the lining of the womb.

If you have a submucosal fibroid (that grows from the muscle wall into the cavity of your womb) it may block a fallopian tube, making it harder for you to conceive (become pregnant). The ovaries (female reproductive organs) release eggs that pass down the fallopian tubes that connect the ovaries to the womb.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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