Uterine fibroids are noncancerous growths of the uterus that often appear during childbearing years. Also called leiomyomas (lie-o-my-O-muhs) or myomas, uterine fibroids aren't associated with an increased risk of uterine cancer and almost never develop into cancer.
Fibroids range in size from seedlings, undetectable by the human eye, to bulky masses that can distort and enlarge the uterus. You can have a single fibroid or multiple ones. In extreme cases, multiple fibroids can expand the uterus so much that it reaches the rib cage.
Many women have uterine fibroids sometime during their lives. But most women don't know they have uterine fibroids because they often cause no symptoms. Your doctor may discover fibroids incidentally during a pelvic exam or prenatal ultrasound.
Many women who have fibroids don't have any symptoms. In those that do, symptoms can be influenced by the location, size and number of fibroids. In women who have symptoms, the most common symptoms of uterine fibroids include:
- Heavy menstrual bleeding
- Menstrual periods lasting more than a week
- Pelvic pressure or pain
- Frequent urination
- Difficulty emptying the bladder
- Backache or leg pains
Rarely, a fibroid can cause acute pain when it outgrows its blood supply, and begins to die.
Fibroids are generally classified by their location. Intramural fibroids grow within the muscular uterine wall. Submucosal fibroids bulge into the uterine cavity. Subserosal fibroids project to the outside of the uterus.
When to see a doctor
See your doctor if you have:
- Pelvic pain that doesn't go away
- Overly heavy, prolonged or painful periods
- Spotting or bleeding between periods
- Difficulty emptying your bladder
Seek prompt medical care if you have severe vaginal bleeding or sharp pelvic pain that comes on suddenly.
Doctors don't know the cause of uterine fibroids, 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.
- 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.
Doctors believe that uterine fibroids develop from a stem cell in the smooth muscular tissue of the uterus (myometrium). A single cell divides repeatedly, eventually creating a firm, rubbery mass distinct from nearby tissue.
The growth patterns of uterine fibroids vary — they may grow slowly or rapidly, or they may remain the same size. Some fibroids go through growth spurts, and some may shrink on their own. Many fibroids that have been present during pregnancy shrink or disappear after pregnancy, as the uterus goes back to a normal size.
There are few known risk factors for uterine fibroids, other than being a woman of reproductive age. Other factors that can have an impact on fibroid development include:
- Heredity. If your mother or sister had fibroids, you're at increased risk of developing them.
- Race. Black women are more likely to have fibroids than women of other racial groups. In addition, black women have fibroids at younger ages, and they're also likely to have more or larger fibroids.
- Environmental factors. Onset of menstruation at an early age; use of birth control; obesity; a vitamin D deficiency; having a diet higher in red meat and lower in green vegetables, fruit and dairy; and drinking alcohol, including beer, appear to increase your risk of developing fibroids.
Although uterine fibroids usually aren't dangerous, they can cause discomfort and may lead to complications such as anemia from heavy blood loss.
Pregnancy and fibroids
Fibroids usually don't interfere with getting pregnant. However, it's possible that fibroids — especially submucosal fibroids — could cause infertility or pregnancy loss. Fibroids may also raise the risk of certain pregnancy complications, such as placental abruption, fetal growth restriction and preterm delivery.
Uterine fibroids are frequently found incidentally during a routine pelvic exam. Your doctor may feel irregularities in the shape of your uterus, suggesting the presence of fibroids. 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 have abnormal menstrual 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.
Other imaging tests
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 submucosal fibroids and the endometrium.
- 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.
There's no single best approach to uterine fibroid treatment — many treatment options exist. If you have symptoms, talk with your doctor about options for symptom relief.
Many women with uterine fibroids experience no signs or symptoms, or only mildly annoying signs and symptoms that they can live with. If that's the case for you, watchful waiting could be the best option.
Fibroids aren't cancerous. They rarely interfere with pregnancy. They usually grow slowly — or not at all — and tend to shrink after menopause, when levels of reproductive hormones drop.
Medications for uterine fibroids target hormones that regulate your menstrual cycle, treating symptoms such as heavy menstrual bleeding and pelvic pressure. They don't eliminate fibroids, but may shrink them. Medications include:
Gonadotropin-releasing hormone (Gn-RH) agonists. Medications called Gn-RH agonists (Lupron, Synarel, others) treat fibroids by blocking the production of estrogen and progesterone, putting you into a temporary postmenopausal state. As a result, menstruation stops, fibroids shrink and anemia often improves. Your doctor may prescribe a Gn-RH agonist to shrink the size of your fibroids before a planned surgery.
Many women have significant hot flashes while using Gn-RH agonists. Gn-RH agonists typically are used for no more than three to six months because symptoms return when the medication is stopped and long-term use can cause loss of bone.
- Progestin-releasing intrauterine device (IUD). A progestin-releasing IUD can relieve heavy bleeding caused by fibroids. A progestin-releasing IUD provides symptom relief only and doesn't shrink fibroids or make them disappear. It also prevents pregnancy.
- Tranexamic acid (Lysteda). This nonhormonal medication is taken to ease heavy menstrual periods. It's taken only on heavy bleeding days.
Other medications. Your doctor might recommend other medications. For example, oral contraceptives or progestins can help control menstrual bleeding, but they don't reduce fibroid size.
Nonsteroidal anti-inflammatory drugs (NSAIDs), which are not hormonal medications, may be effective in relieving pain related to fibroids, but they don't reduce bleeding caused by fibroids. Your doctor may also suggest that you take vitamins and iron if you have heavy menstrual bleeding and anemia.
MRI-guided focused ultrasound surgery (FUS) is:
- A noninvasive treatment option for uterine fibroids that preserves your uterus, requires no incision and is done on an outpatient basis.
- Performed while you're inside an MRI scanner equipped with a high-energy ultrasound transducer for treatment. The images give your doctor the precise location of the uterine fibroids. When the location of the fibroid is targeted, the ultrasound transducer focuses sound waves (sonications) into the fibroid to heat and destroy small areas of fibroid tissue.
- Newer technology, so researchers are learning more about the long-term safety and effectiveness. But so far data collected show that FUS for uterine fibroids is safe and effective.
Minimally invasive procedures
Certain procedures can destroy uterine fibroids without actually removing them through surgery. They include:
- Uterine artery embolization. Small particles (embolic agents) are injected into the arteries supplying the uterus, cutting off blood flow to fibroids, causing them to shrink and die. This technique can be effective in shrinking fibroids and relieving the symptoms they cause. Complications may occur if the blood supply to your ovaries or other organs is compromised.
- Myolysis. In this laparoscopic procedure, radiofrequency energy, an electric current or laser destroys the fibroids and shrinks the blood vessels that feed them. A similar procedure called cryomyolysis freezes the fibroids.
Laparoscopic or robotic myomectomy. In a myomectomy, your surgeon removes the fibroids, leaving the uterus in place. If the fibroids are small and few in number, you and your doctor may opt for a laparoscopic or robotic procedure, which uses slender instruments inserted through small incisions in your abdomen to remove the fibroids from your uterus. The fibroids are removed by breaking them into smaller pieces, a process called morcellation.
Your doctor views your abdominal area on a monitor using a small camera attached to one of the instruments. Robotic myomectomy gives your surgeon a magnified, 3-D view of your uterus, offering more precision, flexibility and dexterity than is possible using some other techniques.
- Hysteroscopic myomectomy. This procedure may be an option if the fibroids are contained inside the uterus (submucosal). Your surgeon accesses and removes fibroids using instruments inserted through your vagina and cervix into your uterus.
Endometrial ablation. This treatment, performed with a specialized instrument inserted into your uterus, uses heat, microwave energy, hot water or electric current to destroy the lining of your uterus, either ending menstruation or reducing your menstrual flow.
Typically, endometrial ablation is effective in stopping abnormal bleeding. Submucosal fibroids can be removed at the time of hysteroscopy for endometrial ablation, but this doesn't affect fibroids outside the interior lining of the uterus.
Traditional surgical procedures
Options for traditional surgical procedures include:
- Abdominal myomectomy. If you have multiple fibroids, very large fibroids or very deep fibroids, your doctor may use an open abdominal surgical procedure to remove the fibroids. Many women who are told that hysterectomy is their only option can have an abdominal myomectomy instead. However, scarring after surgery can affect future fertility.
Hysterectomy. This surgery — the removal of the uterus — remains the only proven permanent solution for uterine fibroids. But hysterectomy is major surgery.
It ends your ability to bear children. And if you also elect to have your ovaries removed, it brings on menopause and the question of whether you'll take hormone replacement therapy. Most women with uterine fibroids may be able to choose to keep their ovaries.
Morcellation during fibroid removal
There's been some concern that morcellation — a process of breaking fibroids into smaller pieces —might increase the risk of spreading cancer if a previously undiagnosed cancerous mass undergoes morcellation during myomectomy. However, the risk that a pre-menopausal woman has cancer rather than a fibroid is generally lower than the risk of complications associated with fibroid surgery. If your doctor is planning to use morcellation, discuss your individual risk before treatment.
The Food and Drug Administration (FDA) advises against morcellation for most women. In particular, the FDA recommends that women who are peri- or post-menopausal avoid morcellation. Older women in or entering menopause may have a higher cancer risk, and women who are no longer concerned about preserving their fertility have additional treatment options for fibroids.
If you still might want to have children
Hysterectomy and endometrial ablation are the only two treatment options that can't be used by women who want to preserve the ability to become pregnant. Before deciding on a treatment plan for fibroids, a complete fertility evaluation is recommended.
If fibroid treatment is needed, myomectomy is generally the treatment of choice. However, all treatments have risks and benefits. Discuss these with your doctor.
Risk of developing new fibroids
For all procedures except hysterectomy, seedlings — tiny tumors that your doctor doesn't detect during surgery — could eventually grow and cause symptoms that warrant treatment. This is often termed the recurrence rate. New fibroids, which may or may not require treatment, also can develop.
Some websites and consumer health books promote alternative treatments, such as specific dietary recommendations, magnet therapy, black cohosh, herbal preparations or homeopathy. So far, there's no scientific evidence to support the effectiveness of these techniques.
Your first appointment will likely be with either your primary care provider or a gynecologist. Because appointments can be brief, it's a good idea to prepare in advance for your appointment.
What you can do
- Make a list of any symptoms you're experiencing. Include all of your symptoms, even if you don't think they're related.
- List any medications, herbs and vitamin supplements you take. Include doses and how often you take them.
- Have a family member or close friend accompany you, if possible. You may be given a lot of information during your visit, and it can be difficult to remember everything.
- Take a notebook or electronic device with you. Use it to note important information during your visit.
- Prepare a list of questions to ask your doctor. List your most important questions first, in case time runs out.
For uterine fibroids, some basic questions to ask include:
- How many fibroids do I have? How big are they?
- Are the fibroids located on the inside or outside of my uterus?
- What kinds of tests might I need?
- What medications are available to treat uterine fibroids or my symptoms?
- What side effects can I expect from medication use?
- Under what circumstances do you recommend surgery?
- Will I need a medication before or after surgery?
- Will my uterine fibroids affect my ability to become pregnant?
- Can treatment of uterine fibroids improve my fertility?
Make sure that you understand everything your doctor tells you. Don't hesitate to have your doctor repeat information or to ask follow-up questions.
What to expect from your doctor
Some questions your doctor might ask include:
- How often do you have these symptoms?
- How long have you been experiencing symptoms?
- How severe are your symptoms?
- Do your symptoms seem to be related to your menstrual cycle?
- Does anything improve your symptoms?
- Does anything make your symptoms worse?
- Do you have a family history of uterine fibroids?
Although researchers continue to study the causes of fibroid tumors, little scientific evidence is available on how to prevent them. Preventing uterine fibroids may not be possible, but only a small percentage of these tumors require treatment.
But, by making healthy lifestyle choices, such as maintaining a normal weight and eating fruits and vegetables, you may be able to decrease your fibroid risk.