What are fibroids?

Fibroids are growths which develop inside the womb (uterus). They are usually non-cancerous and often there is more than one. The medical term for a fibroid is a uterine myoma or fibromyoma (referred to as myomata or fibromyomata if there are multiple fibroids present).

Fibroids can cause problems and need treatment but they are not usually life-threatening. They often develop within the muscle wall of the womb but can also grow in other areas - the symptoms may be different depending on the site of the fibroid(s).

  • Intramural fibroids form within the muscle wall of the womb itself - if they then grow, they cause the womb to increase in size.
  • Subserous fibroids grow away from the outer muscle wall of the womb. They can grow on a stalk which can become twisted.
  • Submucous fibroids grow inside the womb under the lining (the endometrium) and can cause heavy bleeding.
  • Occasionally, fibroids can develop in the cervix (cervical fibroids) - these can enlarge into the vagina.

A woman may have multiple fibroids of different sizes which can occur simultaneously in any of these areas.

What are the symptoms of fibroids?

Very often, women have no symptoms and may not even know that they have fibroids. Symptoms are not necessarily related to the size or number of the fibroids but, usually, the bigger or more numerous they are the more likely they are to cause problems.

The most common symptom caused by fibroids is heavy, prolonged periods (menorrhagia). This heavy bleeding may cause some women to become anaemic. Fibroids can cause the womb to become bulky and enlarged causing pressure in the pelvic region. This can result in symptoms such as backache, lower abdominal pain, and the need to urinate more frequently (as a result of pressure on the bladder).

Fibroids may cause fertility problems in some women, particularly if the fibroids grow out into the womb and prevent an embryo from implanting.

What causes fibroids?

It is not really known what causes fibroids. High levels of oestrogen may influence their growth but do not cause them to occur in the first place. Fibroids can occur in women with children but are more common in women with lower fertility or those without children. Being very overweight may increase the risk of developing fibroids as body fat produces oestrogen independently of the ovaries; however, slim women can also develop fibroids. Fibroids are more common in African Americans than Caucasians, and less common in women who smoke.

Are there any tests necessary?

An internal vaginal examination may often be enough to diagnose small fibroids that are not causing problems. A blood test will show if anaemia (caused by heavy bleeding) is present; hormone levels may also be checked at the same time.

An ultrasound of the abdomen may be ordered to enable the size and location of the fibroids to be established. This procedure is painless and takes about 15 minutes.

Alternatively, a hysteroscopy may be performed. This is a procedure in which a fibre-optic tube which relays images to a video camera is inserted into the womb via the cervix, usually under local anaesthetic. This allows the doctor to see inside the womb. In some cases fibroids may be detected by laparoscopy, where a fibre-optic tube is inserted into the abdominal cavity via a small incision in the abdomen.

What treatment is available?

The type of treatment recommended will depend on the symptoms being caused by the fibroids and on whether or not you wish to remain fertile. If the main problem is heavy periods, then a hormone treatment such as the contraceptive pill or a progestogen (progesterone or norethisterone) may be prescribed. These treatments are usually given for six months. If you are nearing menopause, hormonal treatment is usually sufficient as fibroids tend to shrink after the menopause.

If hormone treatment is not sufficient to control the symptoms, then surgery may be advised. If you wish to remain fertile and conceive, removal of the fibroids may be carried out. If the fibroids are fairly small, they may be removed using a hot wire loop inserted during a hysteroscopy (see above). This can usually be carried out as day surgery.

Large fibroids may need to be removed by myomectomy which involves an abdominal incision. If the fibroids are troublesome and you do not wish to have any more children, a hysterectomy (complete removal of the cervix and womb) may be performed. This can be via an abdominal incision (total abdominal hysterectomy) or via the top of the vagina (total vaginal hysterectomy). Depending on your age the ovaries may or may not be removed at the same time.

If the surgical option is chosen, drug therapy will be given beforehand to shrink the fibroids.

A group of drugs known as GnRH analogues may be used to manage fibroids pre-operatively to reduce their size and associated bleeding. These treatments will effectively make you menopausal by switching off the production of hormones by the ovaries - without oestrogen the fibroids will shrink. These include leuprorelin (Prostap® SR DCS) and triptorelin (eg, Decapeptyl® SR, Gonapeptyl®). Because of the way these treatments work they can cause side effects similar to symptoms of the menopause, such as hot flushes, vaginal dryness and psychological changes.

Alternatively, a drug called ulipristal acetate (Esmya®) may be given for up to 3 months before surgery or used intermittently in 3-month courses to treat moderate to severe symptoms. It exerts a direct action on fibroids by modulating the effects of progesterone.

Iron tablets, such as ferrous sulphate or ferrous gluconate, will be prescribed if you are anaemic.

Further information available from:

Fibroids Connect

Fact sheet provided by MIMS

Date last reviewed: September 2014

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