What are fibroids?

Uterine fibroids (leiomyomata) are non-cancerous growths that develop in or just outside a woman’s uterus (womb). Uterine fibroids often appear during childbearing years and aren't associated with an increased risk of uterine cancer and almost never develop into cancer.

Although these tumors are called fibroids, this term is misleading because they consist of muscle tissue, not fibrous tissue. The medical term for a fibroid is leiomyoma, a type of myoma or mesenchymal tumor.

Fibroids start in the muscle tissues of the uterus. They can grow into the uterine cavity (submucosal), into the thickness of the uterine wall (intramuscular), or on the surface of the uterus (subsersoal) into the abdominal cavity. Some may occur as pedunculated masses (fibroids growing on a stalk off of the uterus).

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.
 

What are fibroids causes?

The cause of uterine fibroids remains unknown, but research and clinical experience point to these factors:

Genetic changes. Many fibroids contain changes in genes that differ from those in normal uterine muscle cells. There's also some evidence that fibroids run in families and that identical twins are more likely to both have fibroids than nonidentical twins.

Hormones. Estrogen and progesterone, two hormones that stimulate development of the uterine lining during each menstrual cycle in preparation for pregnancy, appear to promote the growth of fibroids. Fibroids contain more estrogen and progesterone receptors than normal uterine muscle cells do. Fibroids tend to shrink after menopause due to a decrease in hormone production.

Other growth factors. Substances that help the body maintain tissues, such as insulin-like growth factor, may affect fibroid growth.
 

What are fibroids symptoms?

Most often, uterine fibroids cause no symptoms at all -- so most women don’t realize they have them. When women do experience symptoms from uterine fibroids, they can include:
- Prolonged menstrual periods (7 days or longer)
- Heavy bleeding during periods
- Bloating or fullness in the belly or pelvis
- Pain in the lower belly or pelvis
- Constipation
- Pain with intercourse
- Miscarriage or infertility
- Problems during pregnancy

Some experts believe that some uterine fibroids can occasionally interfere with fertility and pregnancy. Rarely, a uterine fibroid projecting into the uterus might either block an embryo from implanting there, or cause problems with the pregnancy later.
 

What are the usual ways of diagnosing fibroids?

Uterine fibroids are diagnosed by pelvic exam and even more commonly by ultrasound.

If you have symptoms of uterine fibroids, you doctor may order these tests:

Ultrasound. If confirmation is needed, your doctor may order an ultrasound. It uses sound waves to get a picture of your uterus to confirm the diagnosis and to map and measure fibroids. A doctor or technician moves the ultrasound device (transducer) over your abdomen (transabdominal) or places it inside your vagina (transvaginal) to get images of your uterus.
Lab tests. If you're experiencing abnormal vaginal bleeding, your doctor may order other tests to investigate potential causes. These might include a complete blood count (CBC) to determine if you have anemia because of chronic blood loss and other blood tests to rule out bleeding disorders or thyroid problems.

If traditional ultrasound doesn't provide enough information, your doctor may order other imaging studies, such as:

Magnetic resonance imaging (MRI). This imaging test can show the size and location of fibroids, identify different types of tumors and help determine appropriate treatment options.
Hysterosonography. Hysterosonography (his-tur-o-suh-NOG-ruh-fee), also called a saline infusion sonogram, uses sterile saline to expand the uterine cavity, making it easier to get images of the uterine cavity and endometrium. This test may be useful if you have heavy menstrual bleeding despite normal results from traditional ultrasound.
Hysterosalpingography. Hysterosalpingography (his-tur-o-sal-ping-GOG-ruh-fee) uses a dye to highlight the uterine cavity and fallopian tubes on X-ray images. Your doctor may recommend it if infertility is a concern. In addition to revealing fibroids, it can help your doctor determine if your fallopian tubes are open.
Hysteroscopy. For this, your doctor inserts a small, lighted telescope called a hysteroscope through your cervix into your uterus. Your doctor then injects saline into your uterus, expanding the uterine cavity and allowing your doctor to examine the walls of your uterus and the openings of your fallopian tubes.
 

How to treat fibroids?

There's no single best approach to uterine fibroid treatment — many treatment options exist.

Some medicines are used to treat heavy periods with whatever the cause, including heavy period that are caused by fibroids. Some women are given a gonadotrophin-releasing hormone (GnRH) analogue in order to shrink the fibriods. Sometimes a low dose of HRT is also given to reduce the incidence of menopausal side-effects.

Surgeries and other operative treatments including:

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 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. See separate leaflet called 'Hysterectomy' for more detail.

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 an incision (cut) 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 catheter (a thin flexible tube) into an artery (blood vessel) 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.