Uterine fibroids are benign (not cancer) growths that develop from the muscle tissue of the uterus. They also are called leiomyomas or myomas. The size, shape, and location of fibroids can vary greatly. They may be inside the womb (uterus), on its outer surface, within its wall or attached to it by a stem-like structure. A woman may have only one fibroid or many of varying sizes. Fibroids can increase in size, decrease in size or even go away with time. A change in size may take place rapidly or slowly over several years.
Fibroids can occur anywhere in the womb and are named according to where they grow:
- Intramural – grow within the muscle tissue of the womb (most common).
- Subserous – grow from the outside wall of the womb into the pelvis.
- Submucous – grow from the inner wall into the cavity of the womb.
- Pedunculated – grow from the wall of the womb and are attached to it by a narrow stalk.
Why does fibroids develop?
It is not clear why fibroids 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 (e.g. after the menopause). This shrinkage of the fibroids after the menopause may be delayed if you take hormone replacement therapy.
Who is most likely to have fibroids?
Fibroids are very common. It is difficult to know exactly how common they are as many women won’t have any symptoms, and so may not know they have fibroids. Probably at least 1 in 2 women develop one or more fibroids in their lifetime. Fibroids are most common in women aged 30–40 years, but they can occur at any age. Fibroids occur more often in African American women than in white women. They also seem to occur at a younger age and grow more quickly in African American women.
What are symptoms of fibroids?
Most women who have fibroids are not aware that they have them as they do not have any symptoms. 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:
- Changes in menstruation:
- Longer or heavy menstrual periods
- Menstrual pain (cramps)
- Vaginal bleeding at times other than menstruation
- Iron-deficiency (from blood loss)
- In the abdomen or lower back (often dull, heavy and aching, but may also be sharp)
- During sex
- Pressure symptoms:
- Difficulty in urinating or more frequent urination
- Constipation, rectal pain, or difficult bowel movements
- Abdominal pain
- Enlarged uterus and abdomen
- Infertility: If the fibroids grow into the cavity of the womb, they can sometimes block the fallopian tubes or interfere with implantation. This can cause problems conceiving, although this is not common.
Very rarely, fibroids can be a cause of miscarriages.
What complications can occur with fibroids?
Fibroids that are attached to the uterus by a stem may twist (torsion) and can cause pain, nausea, or fever. Fibroids that grow rapidly, or those that start breaking down, also may cause pain. A very large fibroid may cause swelling of the abdomen. Fibroids may occasionally contribute to infertility or miscarriages. However, most of the time they are just innocent bystanders and a coincidental finding during ultrasound examination.
Can fibroids be associated with cancer?
Fibroids may rarely be associated with cancer. In the age group below 40 years the risk for this is extremely low (0.2%) and increases to about 1.7 % in women over 60 years.
What about fibroids in pregnancy?
Having one or more fibroids does not cause any problems in the vast majority of women when they are pregnant. Occasionally, you may have pain or discomfort from your fibroid. This may be caused by the fibroid growing too large for its blood supply or twisting, if the fibroid has a stalk (also called pedunculated). However, fibroids can be associated with an increased risk of having a caesarean section, abnormal fetal positions (e.g. the baby lying bottom-first rather than head-first) and early (premature) labour.
How are fibroids diagnosed?
The first signs of fibroids may be detected during a routine pelvic exam. A number of tests may show more information about fibroids:
- Transvaginal ultrasound scan – A probe (not painful) placed inside the vagina to create a picture from the pelvic organs using sound waves.
- Hysteroscopy – A thin, lighted scope is inserted through the vagina and the opening of the cervix (see section on hysteroscopy) to see the inside of the uterus.
- Hysterosalpingography is a special X-ray test. It may detect abnormal changes in the size and shape of the uterus and fallopian tubes.
- Laparoscopy uses a slender device (the laparoscope) to help your health care professional see the inside of the abdomen. It is inserted through a small cut just below or through the navel. Fibroids on the outside of the uterus can be seen with the laparoscope (see section on laparoscopy).
- Other imaging tests, such as magnetic resonance imaging (MRI) and computed tomography scans are rarely needed.
When is treatment necessary for fibroids?
Fibroids that do not cause symptoms, are small, or occur in a woman who is nearing menopause often do not require treatment. Certain signs and symptoms may signal the need for treatment:
- Heavy or painful menstrual periods that cause anaemia or that disrupt a woman’s normal activities
- Bleeding between periods
- Uncertainty whether the growth is a fibroid or another type of tumour, such as from ovarian origin
- Rapid increase in growth of the fibroid
- Pelvic pain
- Recurrent miscarriages
Can medication be used to treat fibroids?
Drug therapy is an option for some women with fibroids. Medications may reduce the heavy bleeding and painful periods that fibroids sometimes cause. They may not prevent the growth of fibroids. Surgery often is needed later. Drug treatment for fibroids includes the following options:
- Tranexamic acid – These tablets are taken 3 times a day, for the duration of each period to reduce heavy bleeding. It works by reducing the breakdown of blood clots in the womb (uterus).
- Anti-inflammatory medicines – Such as ibuprofen and mefenamic acid. These help to ease period pain and at the same time decreasing the amount of bleeding. They are taken for a few days at the time of your period (see section on abnormal uterine bleeding).
Birth control pills and other types of hormonal birth control methods
– These drugs often are used to control heavy bleeding and painful periods.
Gonadotropin-releasing hormone (GnRH) agonists
– These drugs stop the menstrual cycle and can shrink fibroids by causing a temporary “menopausal” state. They sometimes are used before surgery to reduce the risk of bleeding. Because GnRH agonists have many side effects, they are used only for short periods (less than 6 months). After a woman stops taking a GnRH agonist, her fibroids usually return to their previous size.
Progestin–releasing intrauterine device (IUD) –
This option is for women with fibroids that do not distort the inside of the uterus. It reduces heavy and painful bleeding but does not treat the fibroids themselves.
What types of surgery may be done to treat fibroids?
- Myomectomy is the surgical removal of fibroids while leaving the uterus in place. Because a woman keeps her uterus, she may still be able to have children. Most of the time this can be performed via laparoscopy (see section on laparoscopy) which is minimally invasive (key-hole surgery). This is performed under general anaesthesia and the patient can often go home on the first post-operative day. Sick leave is only needed for 2 – 3 weeks after which the patient can return to her normal duties. Fibroids do not regrow after surgery, but new fibroids may develop. If they do, more surgery may be needed.
- Hysterectomy is the removal of the uterus and is the most definite treatment for fibroids. The ovaries may or may not be removed. Hysterectomy is done when other treatments have not worked or are not possible because of very large fibroids. A woman is no longer able to have children after having a hysterectomy.
If the fibroids are not too large the hysterectomy can be performed via laparoscopy (see section on laparoscopy) which is minimally invasive (key-hole surgery). This is performed under general anaesthesia and the patient can often go home on the first post-operative day. Sick leave is only needed for 2 – 3 weeks after which the patient can return to her normal duties.
Are there other treatments besides medication and surgery?
Other treatment options are as follows:
- Hysteroscopic resection – This technique can only be used to remove fibroids (submucous fibroids) that protrude into the cavity of the womb. A resectoscope is inserted through the cervix to remove the fibroids in small chips using electricity. Hysteroscopy can be performed as a same-day procedure (requiring no overnight stay).
- Uterine artery embolization – In this procedure, tiny particles (about the size of grains of sand) are injected into the blood vessels that lead to the uterus. The particles cut off the blood flow to the fibroid and cause it to shrink. This treatment is performed as an outpatient procedure by a specially trained X-ray doctor and is extremely expensive. Even though symptoms initially improve they often recur in the future and about one in every three women will need further treatment. This procedure should not be performed if future fertility is still desired.
- Endometrial ablation – This is a procedure aimed at damaging the lining of the uterus permanently by destroying it with heat, cold or electrical energy. A patient should NOT get pregnant after this procedure and therefore a sterilization is often performed at the same time. This method is usually recommended for fibroids close to the inner lining of the womb but not inside the cavity. This procedure is utilized with good results in patients where no other reason for abnormal bleeding can be found. The success of this procedure is variable and difficult to predict in case of uterine fibroids.