Fibroids are non-cancerous (benign) growths in or around the womb (uterus). They are common and usually cause no symptoms. However, they can sometimes cause heavy periods, tummy (abdominal) swelling and urinary problems. Treatment is available if symptoms occur.
What are fibroids?
A fibroid is a non-cancerous (benign) growth of the womb (uterus). They are also called uterine myomas, fibromyomas or leiomyomas. Their size can vary. Some are the same size as a grain of rice and some can be as big as a melon. Fibroids can increase in size gradually during a womans reproductive life and decrease in size gradually after the menopause. They can occur anywhere in the womb and are named according to where they grow:
- Intramural fibroids grow within the muscle tissue of the womb. This is the most common place for fibroids to form.
- Subserous fibroids grow from the outside wall of the womb into the pelvis.
- Submucous fibroids grow from the inner wall into the middle of the womb.
- Pedunculated fibroids grow from the outside wall of the womb and are attached to it by a narrow stalk.
How common are fibroids?
- They are common. At least 1 in 4 women develop one or more fibroids in their lifetime. They usually develop in women aged 30-50 and can sometimes run in families. It is common to have several of various sizes, although some women just have one.
- Fibroids are also more common in women who weigh over 70 kg (11 stones). This is thought to be due to the higher levels of oestrogen hormone that occur in obese and overweight women.
What causes fibroids?
A fibroid is like an overgrowth of smooth muscle cells. (The womb (uterus) is mainly made of smooth muscle.) It is not clear why they develop. Fibroids are sensitive to oestrogen and progesterone, the female hormones that are made in the ovary. Fibroids tend to swell when levels of female hormones are high – for example, during pregnancy. They also shrink when levels are low – after the menopause. This shrinkage of the fibroids after the menopause may be delayed if you take hormone replacement therapy (HRT).
What symptoms and problems are caused by fibroids?
Symptoms only occur in about 1 in 3 women with fibroids. Many women who have fibroids are not aware that they have them. Sometimes one is found during a routine examination by a doctor or by chance during a scan which you may have for another reason. Symptoms may include:
Fibroids do not disturb the menstrual cycle but bleeding is often heavier than usual. This can lead to low iron levels and to anaemia which will be diagnosed by a blood test. This is easily treated with iron tablets.
Bloating or swelling
If a fibroid is large you may have discomfort or swelling in the lower tummy (abdomen). Some women experience lower back pain due to their fibroids.
Bladder or bowel symptoms
Occasionally, a fibroid if it is large enough may press on the bladder which lies in front of the womb. You may then pass urine more often than usual. Rarely, pressure on the bowel (which lies behind the womb) may cause constipation.
Pain during sexual intercourse
If the fibroids grow near to the vagina or neck of the womb (cervix) then this can cause pain or discomfort during sexual intercourse.
Miscarriage or infertility
If the fibroids grow into the cavity of the womb they can sometimes block the fallopian tubes. This can cause problems conceiving, although this is not common. Very rarely, fibroids can be a cause of repeated miscarriages.
How are fibroids diagnosed?
Some fibroids can be felt during an internal (vaginal) examination by a doctor. Fibroids are diagnosed by ultrasound scan or other scan like a CT or MRI scan. They can also be diagnosed at the time of surgery (laparoscopy or hysteroscopy).
What are the treatment options for fibroids?
If your fibroids are small and not causing any symptoms then treatment is not usually needed. If you have some symptoms but these are not too debilitating then simple medications of the types listed below may well help.
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 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 combined oral contraceptive pill may help you to have lighter periods and can often help with period pain too. If you are unable to take this, the progestogen-only contraceptive pill may help; although there is little evidence, it seems to help, especially if it makes your periods lighter or stops them altogether.
- The levonorgestrel intrauterine system (LNG-IUS) is a plastic device that sits inside the womb, originally used as a contraceptive. It is inserted into the womb and slowly releases a regular small amount of progestogen hormone called levonorgestrel. It works by keeping the lining of the womb very thin, so bleeding is lighter.
If surgery is planned then medication can be taken to shrink fibroids
- In women who are not wishing to preserve their fertility and are going to have either a hysterectomy or endometrial ablation, a gonadotrophin-releasing hormone (GnRH) analogue can be prescribed. This will cause the fibroids and womb to shrink by up to 30%. This can temporarily ease heavy periods and pressure symptoms due to fibroids but this treatment is given for a maximum of six months. It allows the body’s blood count to improve and makes an endometrial ablation more likely to work or improves the chances of being able to perform a hysterectomy laparoscopically.
- A myomectomy would be performed on women wishing to preserve their fertility