Fibroids

DEFINITION — Fibroids are growths of the uterus, or womb (show figure 1). They are also called uterine leiomyomas or myomas. They grow from the muscle cells of the uterus and may protrude from the inside or outside surface of the uterus. Fibroids may also be found within the muscular wall (show figure 2). Fibroids are not cancerous or pre-cancerous.

Fibroids are very common. At least 25 percent of women have signs of fibroids that can be detected by a pelvic examination, although not all women have symptoms.

CAUSES — Although the exact cause of fibroids is unknown, their growth seems to be related to the hormones estrogen and progesterone. When these hormone levels decrease at menopause, many of the symptoms of fibroids begin to resolve. However, it is not clear that hormones actually cause the fibroids. For example, women who have had high levels of both of these hormones as a result of pregnancy or birth control pills have a lower incidence of fibroids later in life.

RISK FACTORS — A number of factors influence the risk of developing fibroids. These include:

Ethnic background — Fibroids are three times more common in black women as compared to white, non-Hispanic women. In studies of women undergoing hysterectomy (removal of the uterus), black women were significantly more likely to have fibroids, were younger at the time of diagnosis and hysterectomy, and had more severe problems associated with fibroids as compared to white women.

Number of pregnancies — Women with one or more pregnancies that extended beyond 5 months have a decreased risk of fibroid formation.

Use of birth control — Women who use birth control pills have a lower risk of developing fibroids, although women who use the pill at an early age (between age 13 and 16) may have an increased risk. Similar to the birth control pill, women who use using continuous progestin contraceptives (for example, Depo Provera®) have a lower risk of fibroids. (See "Patient information: Contraception").

Smoking — Women who smoke appear to have a decreased risk of fibroids in some studies. However, any small benefit is clearly outweighed by the many serious health risks associated with cigarette smoking.

Diet — Significant consumption of beef, ham, or other red meats is associated with an increased risk of fibroids, while consumption of green vegetables decreases risk. However, no study has shown that changes in diet influence changes in the incidence or symptoms of fibroids. Women who consume alcohol, especially beer, have an increased risk of developing fibroids.

SYMPTOMS — The majority of fibroids are small and do not cause any symptoms at all. However, many women with fibroids have significant bleeding and/or pain that interfere with some aspect of their lives. The severity of symptoms is related to the number, size, and location of the fibroids, and fall into three main groups: increased uterine bleeding, pelvic pressure and pain, and problems related to pregnancy and fertility. As noted above, the symptoms tend to decrease at the time of menopause, although women who take hormone replacement may not see this effect.

Increased uterine bleeding — Fibroids can cause an increase in the amount of blood flow and length of a woman's menstrual period. The presence and amount of uterine bleeding is determined mainly by the location and size of the fibroid. Women with fibroids that protrude into the uterus are more likely to have significant increases in bleeding, although women with all types of fibroids can have this problem. If the bleeding is very heavy, anemia (low red blood cell count) can occur.

Bleeding irregularly (between periods) is not a characteristic of fibroids and may indicate another problem. Women with irregular bleeding should speak with their healthcare provider.

Pelvic pressure and pain — Fibroids can range in size from microscopic to the size of a grapefruit or even larger. Larger fibroids may cause a sense of pressure and fullness in the abdomen, similar to that caused by pregnancy. Fibroids of variable sizes can cause other symptoms, depending upon where they are located within the uterus. As an example, if the fibroid is pressing on the bladder, frequent urination or difficulty emptying the bladder can occur. A fibroid near the rectum may cause constipation, and cervical fibroids can cause pain during sexual intercourse.

In rare cases, fibroids can cause sudden and severe pain if the fibroid begins to break down (degenerate) or twist. Pain of this type may be associated with a mild fever, tenderness in the abdomen, and elevation in the white blood cell count. The pain usually resolves in a few days to weeks. Nonsteroidal anti-inflammatory drugs, such as ibuprofen, can be used to treat the discomfort.

Problems with pregnancy and fertility — Some studies have suggested a slightly increased risk of problems during pregnancy in women with very large fibroids, including breech presentation, premature rupture of membranes, premature labor, and placental abruption (a condition in which the placenta separates prematurely from the uterine wall). In addition, women with very large fibroids are at a high risk of cesarean delivery. These problems are more likely if the placenta is implanted over the area of the large fibroid. Nevertheless, nearly all women with fibroids have completely normal pregnancies without complications. (See "Patient information: Cesarean delivery" and see "Patient information: Preterm labor").

The risk of miscarriage and infertility is associated with a type of fibroid that protrudes into the uterine cavity. Typically these fibroids can be easily removed using a hysteroscope (a small telescope-like device inserted through the cervix into the uterus), which reduces this risk.

However, it is not completely clear what role that fibroids play in infertility. An infertile woman who has large or numerous fibroids may want to talk with her doctor about having the fibroids removed, although all other causes of infertility should first be eliminated. (See "Patient information: Evaluation of the infertile couple").

DIAGNOSIS — Fibroids are often diagnosed during a routine pelvic exam. A clinician may feel the enlarged, irregular outline of the uterus through the abdomen. In certain cases, the clinician may wish to confirm the diagnosis of fibroids and exclude other types of masses. Ultrasound is generally preferred, and uses sound waves to visualize the uterus.

Hysterosalpingogram — A hysterosalpingogram (also called HSG or tubogram) may be recommended for a woman who is trying to become pregnant. During this test, an x-ray of the uterus and tubes is taken after dye is inserted through the cervix. The dye outlines the shape of the inside of the uterus and fallopian tubes. This test can diagnose the presence, size, and location of fibroids that may be protruding into the uterine cavity, and shows if the fallopian tubes are patent (open) (show picture 1).

Sonohysterogram — A sonohysterogram (also called SHG or saline-infusion sonogram), uses ultrasound to view the inside of the uterus while a saline solution is inserted through the cervix. This test is most useful in a woman with heavy or long periods who has had a normal pelvic ultrasound. It is possible for a fibroid or endometrial polyp to cause heavy bleeding, but not be visible with traditional ultrasound (show picture 2).

In some cases, the fibroids are found during X-ray, MRI, or ultrasound procedures that are done for another reason.

TREATMENT — In women who have no symptoms from their fibroids, treatment is usually not required. In women with significant symptoms, treatment may be medical or surgical.

Medical treatment — Medical treatment includes the use of medications to treat the symptoms of fibroid-related bleeding and pain. Gonadotropin-releasing hormone (GnRH) agonists are the most common medical treatment for fibroids. Leuprolide (Lupron Depot®) is an example of a GnRH agonist. Most women who use GnRH agonists temporarily stop having menstrual periods and have a significant reduction in the size of their fibroid(s). Reducing or eliminating menstrual bleeding can improve anemia.

However, fibroids rapidly enlarge after GnRH agonists are discontinued. In addition, there are some significant side effects after long-term use, including bone loss leading to osteoporosis. GnRH medications are usually given as a temporary measure (usually no longer than six months), such as while a woman is preparing for surgical treatment. In some cases, using a small dose of estrogen can minimize the side effects of GnRH agonists.

Danazol is an androgenic steroid, and may be used to stop menstrual bleeding. Danazol may be used when it is not necessary to shrink the size of the uterus or for women who cannot take GnRH-agonists. Use of Danazol is generally limited due to bothersome side effects, including weight gain and mood changes.

Surgical treatment — In most women, surgical treatment is used to provide relief from fibroid symptoms. In other cases, surgical procedures are done in an attempt to treat infertility. A number of surgical treatments are available.

Hysterectomy — Hysterectomy is surgical removal of the uterus through the abdomen or vagina. It may be the treatment of choice for some women who have completed childbearing, are not interested in other surgical treatments, and who have severe symptoms. Removal of the ovaries and cervix is not necessary for symptom relief. (See "Patient information: Abdominal hysterectomy").

Abdominal myomectomy — Myomectomy is surgical removal of a fibroid. In an abdominal myomectomy, an incision is made through the abdomen to expose the uterus, and the fibroids are excised from the uterine muscle. It is done in women who do not want to have a hysterectomy, and who have multiple fibroids or significant enlargement of the uterus. Blood loss, time off from work, and complications are similar to that seen with hysterectomy.

Myomectomy preserves the chance of future childbearing and may provide short-term relief of heavy bleeding, but is associated with a significant risk of recurrence. Between 10 and 25 percent of women who have myomectomy will require a second surgery. In addition, abdominal and laparoscopic myomectomy slightly increase the risk of uterine rupture during pregnancy or labor; the risk for most women is small.

Laparoscopic myomectomy — In this procedure, fibroids are removed through a laparoscope, a thin tube inserted through a small incision in the abdomen. A surgeon uses the laparoscope to visualize and remove the fibroids. Laparoscopic myomectomy requires a physician who is skilled in performing this technique, and is usually reserved for women with one or two small fibroids located on the outer surface of the uterus.

Hysteroscopic myomectomy — In this procedure, a telescope-like instrument (hysteroscope) is placed into the vagina, through the cervix and into the uterus. Fibroids may be seen through the hysteroscope and removed. This procedure can only be done on fibroids that are on the inside of the uterus, and it requires a physician who is skilled in performing this technique. This approach decreases menstrual bleeding with little reduction in uterine size.

Endometrial ablation — In this procedure, the lining of the uterus is destroyed with heat by a scope inserted into the vagina through the cervix and into the uterus. It can be done alone, or in combination with other treatments such as hysteroscopic myomectomy or myolysis (explained below). Pregnancy is possible, though not recommended after endometrial ablation; contraception is strongly recommended since a woman continues to ovulate. Endometrial ablation decreases bleeding without affecting uterine size.

Uterine artery embolization — In uterine artery embolization (UAE or UFE), a small catheter is inserted in a large blood vessel and threaded up to blood vessels near a fibroid (show figure 3A-3B). Tiny particles are injected into the blood vessel, which stops blood flow to the fibroid (show figure 4). This causes the fibroid to rapidly decrease in size within days to weeks after UAE.

The procedure appears to provide significant reduction in symptoms with few serious complications, although follow up data is limited to five years. The mean reduction in fibroid volume is comparable to that seen with GnRH-agonist treatment (30 to 40 percent). Post-procedure — Serious complications of UAE are rare, and similar to complications of other fibroid surgeries. Post-procedure pain is generally moderate to severe; most women stay in the hospital and receive intravenous pain medication after their procedure. Fever occurs in approximately one third of women, but is not usually related to infection. A small percentage of women (5 to 8 percent) stop having menstrual periods after UAE, which can be temporary or permanent. This change is more likely in women greater than 50 years of age; 40 percent of these women have no menstrual periods following UAE. Approximately 95 percent of women report significant improvement in symptoms and quality of life after UAE. Pregnancy after UAE — Pregnancy is not recommended for women who have undergone UAE, although normal pregnancies have occurred. UAE can affect ovarian function, potentially increasing the chances of infertility after treatment. Additionally, there is an increased risk of placental abnormalities in pregnancy following UAE. Myolysis — In this procedure, the fibroid tissue is destroyed through a laparoscope inserted in the abdomen. Myolysis can be combined with endometrial ablation, which is more effective than either procedure alone. Focused Ultrasound Surgery — MRI-guided focused ultrasound surgery (MRgFUS) is a new, FDA-approved treatment for fibroids. It involves destroying fibroid tissue with high intensity, focused ultrasound heat energy. The treatment takes place in an MRI machine, which gives live, "real-time" images of the uterus, allowing for progress to be monitored while the procedure is done. Only short-term outcome data is available, but MRgFUS appears to provide good symptom relief without incisions. In addition, it can be done on an outpatient basis. The treatment is not widely available since it is expensive, time consuming, and requires special equipment.

Choosing a treatment — In deciding on the best surgical treatment for fibroids, a number of factors should be considered. One of the most critical is whether or not childbearing has been completed. Although hysterectomy provides excellent relief of symptoms, a woman who wishes to become pregnant in the future may choose myomectomy. A woman who is done with childbearing but who is not interested in hysterectomy may consider uterine artery embolization, myolysis, endometrial ablation, or a combination of the above.

SUMMARY Fibroids are growths of the uterus (womb) (show figure 1 and show figure 2). Fibroids are not cancerous or pre-cancerous. The exact cause of fibroids is unknown (see "Risk factors" above). Most fibroids are small and do not cause any problems. Women with several small fibroids or one large fibroid often have heavy bleeding and/or pain during their menstrual period. This pain and bleeding can cause a woman to miss work or school (see "Symptoms" above). Fibroids may be diagnosed with a pelvic exam or ultrasound test (see "Diagnosis" above). Fibroids may need to be treated if the woman has heavy bleeding or pain. Women who do not have heavy bleeding or pain usually do not need any treatment. A medicine or surgery may be used to shrink the fibroid. Surgery to remove the fibroid or entire uterus is another option (see "Surgical treatment" above). The best type of treatment depends upon whether the woman wants to become pregnant in the future. Some treatments prevent pregnancy (see "Choosing a treatment" above).

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine

(www.nlm.nih.gov/medlineplus/healthtopics.html)
U.S. Department of Health and Human Services

(www.4woman.gov)
Society of Interventional Radiology

(www.sirweb.org, search for "uterine fibroids")
The Cochrane Collaboration

(www.cochrane.org, search for "uterine fibroids")


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