Uterine Fibroids

Uterine fibroids are the most common, non-cancerous tumors in women of childbearing age. The fibroids are made of muscle cells and other tissues that grow within and around the wall of the uterus.

A diagram that shows where uterine fibroids may grow. Source: Wikimedia Commons

Other Names

Other names for fibroids are leiomyomas or simply myomas.

Definition

Fibroids are benign (non-cancerous) balls of uterine muscle cells that grow in the uterus (womb). About one-third of women will develop uterine fibroids, but usually the growths are small and cause no symptoms. Some studies report as many as 70% of white women and 80% of black women will develop fibroids by age 50. In some women however, the fibroids grow large or grow in a location that causes symptoms such as pain and heavy menstrual periods.

Types

Fibroids vary in their location, shape and size. Some women have just one large fibroid. Others develop many small fibroids.

• Submucous fibroids (#2 in the diagram above) are partially located in the cavity of the uterus. These fibroids can cause problems with bleeding because they distort the uterine lining. They also can affect a pregnancy if the pregnancy implants on top of the fibroid. Because blood flow through the fibroid tissue is abnormal, a miscarriage can result. Submucous fibroids can contribute to infertility.
• Intramural fibroids (#3 in the diagram above) are located within the muscle of the uterine wall.
• Pedunculated fibroids hang off the uterus by a stem. These can cause problems if they twist.

They can be confused with the ovaries when visualizing the reproductive organs with ultrasound.

Causes

The exact cause of fibroids is unknown. However, their growth is affected by the hormone estrogen. Fibroids tend to slightly decrease in size after menopause when they are no longer stimulated by estrogen. There is a genetic disposition to fibroids in certain ethnic backgrounds. African American women are much more likely to have fibroids when compared to Caucasian women. Fibroids occur in Hispanic women and Asian women with a similar frequency to Caucasian women.

Risk Factors

There are several risk factors for uterine fibroids:

• Ethnic background–African American women are four times more likely to have fibroids. In this population, the fibroids tend to occur at an earlier age and tend to grow more quickly.
• Women who are overweight or obese for their height are at greater risk.
• Women who have given birth are a lower risk for fibroids.
• Some studies show that use of Birth Control Pills can decrease fibroid growth. Study results are mixed however, with others showing a modest increase in fibroid size. Patients with fibroids who take Birth Control Pills should be closely monitored.

Symptoms

Many women with uterine fibroids have no symptoms. However, fibroids can be more symptomatic depending on their size and location. Symptoms of uterine fibroids include the following:

• Changes in menstruation
  • More bleeding
  • Longer or more frequent menstrual periods
  • Menstrual cramps (pain)
  • Bleeding at times other than during a normal menstrual period
  • Anemia from heavy periods, which can cause significant blood loss

• Pain
  • Pain during the period
  • Back pain or ache
  • Pain during sex

• Fibroids putting pressure on nearby organs
  • Bladder pressure can cause frequent urination
  • Pressure on the rectum can cause rectal pain, constipation or difficult bowel movements
  • Pressure on the abdominal wall from large fibroids can make a woman look pregnant when she is not

• Infertility

• Pregnancy complications can include miscarriage, preterm birth, abnormal position of the baby (breech) and, rarely, a fibroid in the cervix can block the baby from being born normally (vaginally). Cesarean delivery is more common if someone has a large fibroid. Bleeding after delivery can also be increased.

Diagnosis

Fibroids are sometimes picked up on a routine gynecologic pelvic exam, that depends on their size and location.

Several imaging studies are used to detect fibroids:

• Ultrasound uses sound waves to outline structures of organs and display a picture on a monitor
  • a saline Infusion Sonohysterogram is a special ultrasound performed after the uterine cavity has been filled with saline to help outline any uterine cavity abnormalities.
• In a Hysterosalpingogram,a radiologic (X-rays) study, a woman is injected with a dye that highlights the structure of the uterus.

Hysteroscopy is an outpatient surgery in which a doctor inserts a small camera into the uterus to look for fibroids and other issues.

Treatment

Most fibroids do not require treatment. Treatment is usually needed if the fibroids are causing symptoms such as pain or bleeding or if the fibroids are large or rapidly growing.

• Medications
  • Birth Control Pills
  • Levonorgestrel IUD
  • GnRH analogs such as [Lupron], which can shrink the fibroids before surgery
  • Aromatase inhibitors such as anastrozole and letrozole have been used under experimental conditions. These are not currently approved by the FDA for treatment of fibroids.
  • Antiprogesterone agents such as mefipristone are effective in shrinking fibroids.

• Surgery
  • Myomectomy is a surgery in which the fibroids are removed leaving the uterus intact. This surgery is used in women who desire the ability to have children. Fibroids can recur however; in women with multiple fibroids,as many as 50% develop more fibroids after surgery. Blood loss is usually a bit higher in this type of surgery. Myomectomy can be done through a large incision (laparotomy), laparoscopically, or through the vagina using the hysteroscope. Pregnancy rates are good after myomectomy, in some studies as high as 50-60%. If a woman does get pregnant, she will need to have a cesarean delivery.
  • Hysterectomy is the complete removal of the uterus (and fibroids).
  • Endometrial Ablation is a procedure in which the uterine lining is either cauterized or frozen to make the two sides of the uterine cavity stick together. This significantly reduces the amount of bleeding during menstrual periods. This procedure is not recommended for women who would still like to conceive.
  • Uterine Artery Embolization is performed by Interventional Radiologists. In this procedure, a small cut is made in the groin and a catheter (tube) is placed into the femoral artery. Under x-ray guidance, the tip of the catheter is moved to the arteries that feed the fibroid, and then a clotting medicine is used to cut off blood supply to the fibroid so that it will shrink.
  • MRI guided focused ultrasound surgery is a non-invasive approach that uses ultrasound to destroy the proteins in the fibroids.
  • Cryomyolisis entails the laparoscopic or hysteroscopic placement of a cryoprobe into the center of a fibroid and freezing to –100 C to –120 C to cause myoma coagulation.Case series studies have shown that laparoscopic cryomyolysis appears to be effective in causing fibroid shrinkage.Not a clinical choice so far.

Myomectomy Vaginal Fibroid Surgery (from PreOp® Patient Education series)

Research

The effectiveness of uterine-artery embolization was compared to usual surgical treatment of uterine fibroids in a clinical trial of 157 women.^[1] The usual surgery consisted of hysterectomies and myomectomies. Quality of life one year after the procedures was the same in both treatment groups, but duration in the hospital was shorter for women who had embolization (an average of one day and five days in women treated by embolization and usual surgery, respectively). This allowed women in the embolization group to return to normal activities more quickly. Within one year, 12% and 20% of women who had embolization and usual surgery, respectively, had at least one major adverse event. Some women who received embolization needed follow-up treatment and hospitalization. The authors of the study suggest that decisions about interventions be made considering both the better recovery time and the increased risk of the need for further treatment that is associated with embolization.^[1]

In this eye-to-eye interview, we turned to a researcher from NICHD. Dr. Alicia Armstrong is an expert on uterine fibroids, which are the most common, non-cancerous tumors in women of childbearing age.

References

1. ↑ ^{1.0 1.1} Edwards RD, Moss JG, Lumsden MA, et al. Uterine-artery embolization versus surgery for symptomatic uterine fibroids. N Engl J Med. 2007 Jan 25;356(4):360-70. Abstract | Full Text | PDF

• Hindley JT, Law PA, Hickey M, Smith SC, Lamping DL, Gedroyc WM, et al. Clinical outcomes following percutaneous magnetic resonance image guided laser ablation of symptomatic uterine fibroids. Hum Reprod. 2002;17(10):2737-41

• Ciavattini A, Tsiroglou D, Piccioni M, Lugnani F, Litta P, Feliciotti F, et al. Laparoscopic cryomyolysis: an alternative to myomectomy in women with symptomatic fibroids. Surg Endosc. 2004;18(12):1785-8

• Gonzalez-Barcena D, Alvarez RB, Ochoa EP, Cornejo IC, Comaru-Schally AM, Schally AV, et al. Treatment of uterine leiomyomas with luteinizing hormone-releasing hormone antagonist Cetrorelix. Hum Reprod. 1997;12(9):2028-35

External Links

American College of Obstetricians & Gynecologists: Uterine Fibroids

The National Women's Health Information Center: Fibroid FAQs

Center for Uterine Fibroids: About Fibroids