Fibroids are benign (non-cancerous) growths of the uterus (womb). They are also known as uterine fibroids or leiomyomas. The most common symptoms associated with fibroids are heavy or irregular periods, but often there are no symptoms.
About two-thirds of Australian women are estimated to be affected by fibroids at some stage in their lives. Fibroids most commonly affect women aged in their 30s and 40s. They tend to shrink in women who have passed menopause.
It’s possible to have one or several fibroids, which can vary in size from 1 mm to more than 20 cm in width. Not all fibroids need to be treated, but for those that do there are various treatments available. The most suitable treatment for you will depend on factors such as the size of the fibroid(s), your symptoms, your age and whether you may be planning future pregnancies.
Many women with fibroids have no symptoms at all. About a third of women with fibroids do have symptoms, which may include:
- heavy periods;
- irregular periods;
- prolonged periods;
- bleeding between periods or breakthrough bleeding;
- pain or a feeling of pressure in the pelvic area;
- period pain;
- pain in the lower back;
- pain during sex;
- constipation or difficult bowel movements; or
- difficulty urinating (passing water) or frequent urination.
Types of fibroids
Fibroids can be categorised into 3 groups, depending on where they grow.
- Subserosal fibroids grow on the outside of the uterus. Some subserosal fibroids are pedunculated, meaning that they are on a stalk.
- Intramural fibroids grow within the wall of the uterus. This is the most common type.
- Submucosal fibroids grow just beneath the inner lining of the uterus. Submucosal fibroids can also grow on a stalk and are the least common type.
Different types of fibroids may produce different symptoms.
What causes fibroids?
While the exact cause of fibroids is not known, genetic mutations have been found in the cells of fibroids in about 70 per cent of cases.
Fibroids tend to affect women of child-bearing age because their growth appears to be stimulated by the female sex hormones oestrogen and progesterone. The fibroids usually shrink after menopause when the levels of these hormones drops.
Your risk of fibroids may be increased if you:
- have a family history of fibroids;
- are overweight or obese;
- started your periods at an early age;
- have never been pregnant;
- have had few pregnancies;
- have polycystic ovary syndrome (PCOS); or
- drink excessive amounts of alcohol.
If periods are heavy or prolonged this may eventually lead to anaemia. Anaemia can cause symptoms of tiredness, lack of energy and breathlessness.
Fibroids, fertility and pregnancy
Fibroids do not frequently affect fertility or pregnancy, but occasionally they are associated with problems such as difficulty getting pregnant, miscarriage, childbirth complications and premature birth. Submucosal fibroids are the most likely type to affect fertility and pregnancy.
If fibroids are thought to be affecting your ability to get pregnant, removing the fibroids may be recommended. If fibroids are discovered while you are pregnant, your doctor, midwife or obstetrician/gynaecologist (specialist in pregnancy and conditions affecting the female reproductive system) will be able to give you information and advice on the likely effects on your pregnancy and whether treatment is needed.
Can fibroids lead to cancer?
Fibroids are benign (non-cancerous) growths. They are extremely common and do not increase your risk of getting cancer of the uterus or other cancers.
There is a rare type of cancerous (malignant) tumour of the uterus called leiomyosarcoma. These tumours are very uncommon.
Diagnosis and tests
Your doctor will ask about any symptoms suggestive of fibroids and perform a physical examination where they will feel for an enlarged uterus or a mass.
An ultrasound scan can be done to help confirm a diagnosis of fibroids. Images are taken by passing an ultrasound probe over your lower abdomen. Some images may need to be taken transvaginally. This involves having a special ultrasound probe gently placed in your vagina for a few minutes. It can be uncomfortable but shouldn’t hurt.
Sometimes other investigations are also recommended, such as an MRI scan. An MRI can provide detailed images to help in making the diagnosis and deciding on the best form of treatment.
Occasionally, a hysteroscopy may be recommended. This test involves inserting an instrument with a small camera on the end into the vagina and uterus to view the inner lining of the uterus. A small tissue sample (biopsy) may be taken during this procedure.
Your doctor may recommend you have some blood tests if they are unsure of the diagnosis or are concerned that heavy periods may have led to iron-deficiency anaemia.
Because fibroids don’t always cause symptoms, they are sometimes discovered as a result of a routine gynaecological examination or scan that is done for another reason.
Treatments for fibroids
Treatment choices for fibroids depend on several factors, including your age, whether you are having symptoms, and whether you are planning any future pregnancies. The type and size of the fibroid is also considered when deciding on the best treatment.
Your doctor may refer you to a gynaecologist (specialist in conditions affecting the female reproductive system) for further assessment, advice and treatment for fibroids.
If the fibroids are small and not causing any problems, a wait-and-see approach may be adopted, where your doctor will monitor the fibroids over time. In many women, fibroids shrink spontaneously after menopause.
If the fibroids start to get bigger or cause problems, your doctor may recommend treatment.
Hormonal contraceptives to treat symptoms
Hormonal types of contraception can be used to reduce bleeding or pain associated with fibroids. Options to help treat heavy bleeding include a progesterone-releasing IUD (intrauterine device) or the oral contraceptive pill (the pill). While these treatments can help with symptoms, they don’t shrink fibroids.
Hormone-blocking medicines to shrink fibroids and treat symptoms
Hormonal treatments called gonadotrophin-releasing hormone agonists – GnRH agonists – can shrink fibroids and reduce pain and heavy bleeding associated with fibroids. They often stop periods altogether. GnRH agonists work by blocking the production of oestrogen. In Australia, a GnRH agonist called goserelin (brand name Zoladex Implant) is available for the treatment of fibroids, which is given by injection and used for 3 to 6 months.
There are menopause-like side effects, such as hot flushes and vaginal dryness, associated with this treatment due to the blocking effect on the female sex hormones. Long-term use may also increase the risk of developing osteoporosis. Because of these risks and side effects, and the fact that once treatment is stopped the fibroids tend to enlarge again, GnRH agonists are usually recommended for 3 to 6 months before having the shrunken fibroids removed surgically.
A medicine called ulipristal acetate (brand name Esmya) is a relatively new medicine for fibroids. It works by blocking progesterone and can be used to shrink fibroids before surgery. It can also reduce heavy bleeding. Ulipristal tablets are taken daily for up to 3 months. SIde effects can include hot flushes and breast tenderness. This medicine is not currently listed on the PBS (Pharmaceutical Benefits Scheme), and may cost about $400 per month.
GnRH agonists and ulipristal acetate are not suitable for pregnant or breastfeeding women.
Surgery to remove fibroids
There are several different types of surgical treatments for fibroids. The type of surgery will depend on the size and location of the fibroids, and whether you wish to have future pregnancies.
Myomectomy is where the fibroids are removed but the uterus is left in place. Myomectomy is usually recommended for women with fibroids who wish to have future pregnancies. It is also the best treatment for women who have fibroids that are thought to be affecting their ability to get pregnant.
A myomectomy can be done in several ways.
- A laparoscopic myomectomy is keyhole surgery where a laparoscope – a thin instrument with a camera on the end of it – and other instruments are inserted through small cuts in the abdomen.
- Myomectomy can also be done as open surgery, where there is a larger incision (cut) in the abdomen that generally takes longer to recover from.
- A hysteroscopic myomectomy may be an option for treating fibroids that are submucosal (arising from the inner lining of the uterus). It involves the use of an instrument with a small camera on the end that is inserted into the uterus via the vagina and cervix.
Hysterectomy is where the uterus itself is removed. Hysterectomy is the only treatment that prevents the possibility of the fibroids (and symptoms) coming back. But it is not a suitable treatment for women wanting to still have the option of becoming pregnant.
There are different approaches to doing a hysterectomy, including via open abdominal surgery or laparoscopic (keyhole) surgery. A vaginal hysterectomy, where an incision is made at the top of the vagina and the uterus removed through this incision, is not usually suitable if you have large fibroids.
There are risks with any surgery, so your general health will also be considered when discussing with you the risks and benefits of surgical treatment.
Other procedures to remove fibroids
MRI-directed ultrasound technique is a relatively new treatment that uses MRI (magnetic resonance imaging) to visualise the fibroids, which are then destroyed by focused, high-frequency, high-energy sound waves (ultrasound).
Uterine artery embolisation is a procedure that is carried out under X-ray guidance. It involves having a thin tube inserted into an artery in your groin and threaded through to the blood vessels that supply the uterus. Small particles are then injected into this blood vessel with the aim of reducing the blood supply to the fibroid, causing it to shrink.
While these less invasive procedures are associated with faster recovery times, there is a chance that the fibroids will need further treatment in the future. Also, it is not yet known whether these procedures are suitable for women wishing to preserve their fertility, and they are currently not recommended for women who may still want to become pregnant.
At the moment there is little proof that any measures can effectively prevent the development of fibroids. As fibroids seem to occur more often in women who are overweight, it may be protective to maintain a healthy weight. Also, reducing your alcohol consumption may possibly reduce your risk.
Last Reviewed: 06/02/2018
Your Doctor. Dr Michael Jones, Medical Editor.
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