Fibroids are non-cancerous tumours that grow in or around the womb (uterus). The growths are made up of muscle and fibrous tissue and vary in size.
They are sometimes known as uterine myomas or leiomyomas.
Many women are unaware they have fibroids as they do not have any symptoms. Women who do have symptoms may experience:
- tummy (abdominal) or lower back pain
- a frequent need to urinate
- Constipation
- pain or discomfort during sex
- Heavy or painful periods
In rare cases, fibroids can cause significant complications, such as infertility and problems during pregnancy.
symptoms, fibroids are sometimes diagnosed by chance during a routine gynaecological examination, test or scan.
However, you should see your GP if you have persistent symptoms of fibroids so they can investigate possible causes.
If your GP thinks you may have fibroids, they will usually refer you for an ultrasound scan to confirm the diagnosis.
The exact cause of fibroids is unknown. However, they are linked to the hormone oestrogen. Oestrogen is the female reproductive hormone produced by the ovaries (the female reproductive organs).
Fibroids usually develop during a woman's reproductive years (from approximately 16 to 50 years of age) when oestrogen levels are at their highest, and they tend 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).
40% of women developing them at some point in their life. They most often occur in women aged 30 to 50 years.
Fibroids are thought to develop more frequently in women of African Caribbean origin. It is also thought they occur more often in overweight or obese women because being overweight increases the level of oestrogen in the body.
Women who have had children have a lower risk of developing fibroids, and the risk decreases further the more children you have.
Types of fibroids
Fibroids can grow anywhere in the womb and vary in size considerably. Some can be the size of a pea, whereas others can be the size of a melon.
The main types of fibroids are:
- intramural fibroids – the most common type of fibroid, they develop in the muscle wall of the womb
- subserosal fibroids – fibroids that develop outside the wall of the womb into the pelvis and can become very large
- submucosal fibroids – fibroids that develop in the muscle layer beneath the inner lining of the womb and grow into the middle of the womb
In some cases, subserosal or submucosal fibroids are attached to the womb with a narrow stalk of tissue. These are known as pedunculated fibroids.
If fibroids do not cause symptoms, treatment is not needed. They will often shrink and disappear without any treatment over time, particularly after the menopause.
If you do have symptoms caused by fibroids, medication to help relieve the symptoms will usually be recommended first.
If these medications are ineffective, surgery or other less invasive procedures may be recommended.
Medication to improve symptoms
The following medicines are used to treat heavy periods whatever the cause, including heavy periods that are caused by fibroids. These medicines may not work so well if your fibroids are large. However, one or more of the following may be worth a try if your periods are heavy and the fibroids are small:
- Tranexamic acid is taken 3-4 times a day, for the duration of each period. It works by reducing the breakdown of blood clots in the womb (uterus).
- Anti-inflammatory medicines such as ibuprofen and mefenamic acid. These also help to ease period pain. They are taken for a few days at the time of your period. They work by reducing the high level of a chemical (prostaglandin) in the lining of the womb. Prostaglandin seems to contribute to heavy and painful periods.
- The contraceptive pill may help you to have lighter periods and can often help with period pain too.
- Levonorgestrel intrauterine system (LNG-IUS) is similar to the coil that is used for contraception. It is inserted into the womb and slowly releases a regular small amount of progestogen hormone called levonorgestrel. It works by making the lining of the womb very thin, so bleeding is lighter. However, it can sometimes be difficult to insert into the womb in women with fibroids.
Medication to shrink fibroids
Some women are given a gonadotrophin-releasing hormone (GnRH) analogue. This is a hormone medicine that causes you to have a very low level of oestrogen in your body. Fibroids shrink if the level of oestrogen falls. This can ease heavy periods and pressure symptoms due to fibroids. However, a low oestrogen level can cause symptoms similar to going through the menopause (hot flushes, etc). It may also increase the risk of 'thinning' of the bones (osteoporosis). Therefore, this treatment is given for a maximum of six months.
GnRH analogues, such as goserelin (for example, Zoladex®) or leuprorelin acetate (for example, Prostap® SR), are often prescribed for three to four months before having an operation. This will will make it easier to remove fibroids. Sometimes a low dose of HRT is also given to reduce the incidence of menopausal side-effects.
A new medicine called ulipristal acetate (UPA) has also been available since April 2012. It works by blocking the effects of the hormone progestogen. Progestogen is thought to play a role in fibroid development, so (by blocking progesterone) this medicine shrinks fibroids. Clinical trials have shown that this is a good treatment option, although it has not yet been recommended by the National Institute for Health and Care Excellence (NICE). It can be used for a maximum of three months for women who have moderate-to-severe problems from their fibroids.
Surgery and other operative treatments
There are several different operations available to remove and treat fibroids.
Hysterectomy: this is the traditional and most common treatment for fibroids which cause symptoms. Hysterectomy is the removal of the womb. This can be done by making a bikini scar in the lower tummy (abdomen). Or, if the fibroids are small enough, the womb can be removed through the vagina so there are no scars. A hysterectomy may be a good option for women who have completed their family.
Myomectomy: this is a possible alternative, especially in women who may wish to have children in the future. In this operation, the fibroids are removed and the womb is left. This procedure is not always possible. This operation can be done through a cut (incision) in the abdomen, via keyhole surgery (laparoscopically) or through the vagina (hysteroscopically). The type of operation depends on the size, number and position of the fibroids. Recurrence of the fibroid is fairly common after a myomectomy. There is a risk of very heavy bleeding with this operation. Your surgeon should advise you that a hysterectomy may be needed if that situation arose.
Endometrial ablation: this procedure involves removing the lining of the womb. This can be done by different methods. For example, using laser energy, a heated wire loop or by microwave heating. This method is usually only recommended for fibroids close to the inner lining of the womb.
MRI-guided focused ultrasound: this treatment sends pulses of high power ultrasound through the skin of the lower abdomen. It is targeted at the fibroid, using the MRI scanner. It is effective but there is no research yet on the long-term outcome for women trying to conceive.
Uterine artery embolisation: this procedure is done by a specially trained radiologist (X-ray doctor) rather than a surgeon. It involves putting a thin flexible tube (a catheter) into a blood vessel (artery) in the leg. It is guided, using X-ray pictures, to an artery in the womb that supplies the fibroid. Once there, a substance that blocks the artery is injected through the catheter. As the artery supplying the fibroid becomes blocked it means the fibroid loses its blood supply and so the fibroid shrinks. The complete process of fibroid shrinkage takes about 6-9 months but most women notice a marked improvement in their symptoms within three months. There is a good chance of success with this procedure but it does not work in every case.
Other techniques: MRI-guided laser ablation is a newer technique. In this procedure a small needle is put through the skin into the centre of the fibroid. The correct position of the needle is shown by the MRI scan. The laser energy is then passed down the needle, which destroys the fibroid. This technique is not suitable for all types of fibroid. There is not enough evidence currently to justify using this technique routinely.
