What are uterine fibroids?
Uterine fibroids are benign (not cancer) growths that develop from the muscle tissue of the uterus. They also are called leiomyomas or myomas. They are the most common type of growth found in a woman’s pelvis.
Are there different types of fibroids?
The size, shape, and location of fibroids can vary greatly. They may be inside the uterus, on its outer surface or within its wall, or attached to it by a stem-like structure.
Fibroids can range in size from small, pea-sized growths to large, round ones that may be more than 5 to 6 inches wide. As they grow, they can distort the inside as well as the outside of the uterus. Sometimes fibroids grow large enough to completely fill the pelvis or abdomen.
There may be only one fibroid or many of varying sizes. A fibroid may remain very small for a long time and suddenly grow rapidly, or grow slowly over a number of years.
Who is most likely to have fibroids?
Fibroids are most common in women age 30 to 40, but they can occur at any age. Fibroids occur more often in Black women than in White women. They also seem to occur at a younger age and grow more quickly in Black women. These differences may be due to racism and inequities in society, which can increase the risk of health problems. Also, fibroids may run in families, so a family history of fibroids may be a factor as well.
What causes fibroids?
It is not clear what causes fibroids. Some research suggests that they develop from misplaced cells that are in the body before birth. The female hormones estrogen and progesterone appear to be involved in their growth.
Levels of these hormones can increase or decrease throughout your life. For example, menopause causes a decrease in estrogen. Fibroids often shrink when a woman enters menopause. Hormonal medications that contain estrogen, such as birth control pills, may cause fibroids to grow.
What are symptoms of fibroids?
- Changes in menstruation
- Longer, more frequent, or heavy menstrual periods
- Menstrual pain (cramps)
- Vaginal bleeding at times other than menstruation
- Anemia (from blood loss)
- In the abdomen or lower back (often dull, heavy and aching, but may be sharp)
- During sex
- Difficulty urinating or frequent urination
- Constipation, rectal pain, or difficult bowel movements
- Abdominal cramps
- Enlarged uterus and abdomen
Sometimes fibroids cause no symptoms at all. Fibroids may be found during a routine pelvic exam or during tests for other problems.
What complications can occur with fibroids?
Most fibroids do not cause problems, but there can be complications. Fibroids that are attached to the uterus by a stem may twist and can cause pain, nausea, or fever. Fibroids that grow rapidly, or those that start breaking down, may also cause pain. Rarely, they can be associated with cancer.
A very large fibroid may cause swelling of the abdomen. This swelling can make it hard to do a thorough pelvic exam.
Fibroids may cause infertility, although other causes are more common. Other factors should be explored before fibroids are considered the cause of infertility. When fibroids are thought to be a cause, many women are able to get pregnant after they are treated.
How are fibroids diagnosed?
The first signs of fibroids may be found during a routine pelvic exam. A number of tests may show more information about fibroids:
- An ultrasound exam uses sound waves to create a picture of the uterus and other pelvic organs.
- Hysteroscopy uses a thin device (the hysteroscope) to see the inside of the uterus. It is inserted through the vagina and cervix (opening of the uterus). This lets your health care professional see fibroids inside the uterine cavity.
- Laparoscopy uses a thin 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 belly button. Fibroids on the outside of the uterus can be seen with the laparoscope.
Imaging tests, such as magnetic resonance imaging (MRI) and computed tomography (CT) scans, may be used but are rarely needed. Some of these tests may be used to track the growth of fibroids over time.
Do fibroids need treatment?
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 anemia or that disrupt your normal activities
- Bleeding between periods
- Uncertainty whether the growth is a fibroid or another type of tumor, such as an ovarian tumor
- Rapid increase in growth of the fibroid
- Pelvic pain
There are many treatment options for fibroids. The choice of treatment depends on factors such as your own wishes and the size and location of the fibroids.
Can medication be used to treat fibroids?
Medications are 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. Treatment with medications includes the following options:
- Birth control pills and other types of hormonal birth control methods
- Gonadotropin-releasing hormone (GnRH) agonists—These medications stop the menstrual cycle and can shrink fibroids. They are sometimes used before surgery to reduce the risk of bleeding. GnRH agonists have many side effects, including bone loss, osteoporosis, vaginal dryness, and night sweats. After a woman stops taking a GnRH agonist, her fibroids usually return to their previous size.
- GnRH antagonists with hormonal add-back therapy—These medications can be used to treat heavy bleeding for up to 2 years. They do not shrink fibroids. Hormonal medication (add-back therapy) helps reduce side effects, including hot flashes and bone loss.
- 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.
- Tranexamic acid—This medication is used to treat heavy bleeding. It reduces the blood lost during your period, but does not stop your periods.
Many other medications are being studied for the treatment of fibroids.
What types of surgery may be done to treat fibroids?
Myomectomy is the surgical removal of fibroids while leaving the uterus in place. Fibroids do not regrow after surgery, but new fibroids may develop. If they do, more surgery may be needed.
Because you keep your uterus, you may still be able to have children after a myomectomy. But sometimes a myomectomy causes internal scarring that can lead to infertility. If you do get pregnant after a myomectomy, you may need to have a cesarean birth.
Hysterectomy is the removal of the uterus. The ovaries may or may not be removed. Hysterectomy is done when other treatments have not worked or are not possible or the fibroids are very large. You are no longer able to have children after having a hysterectomy.
How is myomectomy done?
The method used depends on the location and size of the fibroids. In laparotomy, an incision (cut) is made in the abdomen. The fibroids are removed through the incision. In laparoscopy, a laparoscope is used to view the inside of the pelvis. Other tools are inserted through another small incision to remove the fibroids.
Hysteroscopy can be used to remove fibroids that protrude into the cavity of the uterus. A resectoscope is inserted through the hysteroscope. The resectoscope destroys fibroids with electricity or a laser beam. Although it cannot remove fibroids deep in the walls of the uterus, it can often control the bleeding these fibroids cause. In most cases, an overnight stay in the hospital is not necessary.
Myomectomy has risks, including bleeding and infection. Hysteroscopy may cause other problems related to the use of fluid during the procedure. Your health care professional can explain all of the risks to you.
How is hysterectomy done?
In a hysterectomy, the uterus may be removed through a cut in the abdomen or through the vagina. The method used depends on the size of the fibroids.
For pain relief, you may be given general anesthesia, which puts you to sleep, or regional anesthesia, which blocks feeling in the lower part of your body. You may need to stay in the hospital for a few days after this procedure.
Are there other treatments besides medication and surgery?
Other treatment options include the following:
- Uterine artery embolization (UAE)—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. UAE can be done as an outpatient procedure in most cases. The effect of UAE on future pregnancies is not clear.
- Radiofrequency ablation (RFA)—This procedure uses energy and heat to shrink the size of fibroids. RFA can be done with laparoscopy, which involves only small incisions. An ultrasound probe and a laparoscope are inserted into the abdomen to help find the fibroids. Then thin needles are inserted through the abdomen into the fibroids, to heat and destroy the fibroid tissue.