Fibroids Patient Information Fact Sheet

What are fibroids?
Fibroids are growths that develop inside the womb (uterus). They are usually noncancerous, and frequently present as more than a singular growth. As many as one  in five women may have fibroids during their childbearing years, while half of all women have fibroids by the age of 50. 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 require 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 proceed to 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 may 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 simultaneously forming 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 anemic. 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 known what causes fibroids. High levels of estrogen may influence their growth, this is not the root cause. 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 estrogen independently of the ovaries; however, slim women can also develop fibroids. They are more common in African Americans than Caucasians, and less common in women who smoke.

What tests detect fibroids?
An internal vaginal examination may often be enough to diagnose small fibroids that are not causing problems. A blood test will show if anemia (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 procedure utilizes a fiber-optic tube that relays images to a video camera inserted into the womb via the cervix, usually under local anesthetic. This allows the doctor to see inside the womb. In some cases, fibroids may be detected by laparoscopy, where a fiber-optic tube is inserted into the abdominal cavity via a small incision in the abdomen.

How are fibroids treated?
The type of treatment recommended will depend on the symptoms being caused by the fibroids and on whether or not you wish to keep fertility intact. If the main problem is heavy periods, then a hormone treatment such as a contraceptive pill (norethindrone [Camila, Errin, Jolivette, Micronor, Nor-QD, Nora-BE]) or a progestin-only pill (progesterone [Prometrium]) 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 menopause.

If hormone treatment is not sufficient to control the symptoms, then surgery may be advised. If you wish to remain fertile and conceive, you may elect to have the fibroids removed. If the fibroids are fairly small, they may be removed using a low-voltage electrified 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. These treatments will effectively make you menopausal by switching off the production of hormones by the ovaries. Without estrogen, the fibroids will shrink. Because of the way these treatments work, they can cause side effects similar to symptoms of menopause, such as hot flashes, vaginal dryness, and psychological changes.

A group of drugs known as GnRH analogs such as leuprolide (Lupron Depot) may be used to manage fibroids preoperatively to reduce their size and associated bleeding. These drugs reduce estrogen to levels similar to those seen in women after menopause. Iron tablets, such as ferrous sulfate (Slow FE) or ferrous gluconate, will be prescribed if you are anemic.

Further information
Center for Uterine Fibroids:
Pubmed Health:

Last Updated: May 2013