Uterine Fibroids (Myomas): Types, Causes, Symptoms, Diagnosis

Uterine Fibroids (Myomas)

Uterine Fibroids (Myomas) are common non-cancerous (benign) tumors of the uterus and are the most frequent reason for recommending a hysterectomy. They grow from the muscular wall of the uterus and are made up of muscle and fibrous tissue. Many women over 35 have fibroids but usually have no symptoms.

In some women, however, fibroids (myomas) may cause heavy bleeding, pelvic discomfort, and pain and occasionally exert pressure on other organs. These symptoms may require treatment. Treatment may take the form of medication to control pain and bleeding, hormone therapy to shrink the tumor, surgery to remove the tumor, or occasionally a hysterectomy.

There are promising new experimental drugs that may temporarily shrink tumors. These drugs may have serious side effects and are generally very costly. There is a type of abdominal surgery (myomectomy) that removes the myoma without removing the uterus.

These treatments may be sufficient or they may offer temporary relief and enable a woman to postpone having a hysterectomy, especially if she still wishes to bear children. In most severe cases a hysterectomy may be recommended.

Some women choose to do nothing since fibroids will often shrink in size as a woman goes through menopause.

What is a Fibroid (Myoma)?

A fibroid is a non-cancerous growth (tumor) made up of mostly fibrous tissue, like a muscle. Fibroids grow in or around the uterus (womb). They are the most common type of growth in a woman’s pelvic area (the pelvis is the bony structure at the bottom of the spine).

Uterine Fibroids (Myomas)

According to the U.S. National Institutes of Health (NIH), 20-25% of women of reproductive age have fibroids. By the age of 50, up to 80% of black women and up to 70% of white women have fibroids.

Uterine fibroids are most common in women who are in their 40s and early 50s, although some women may develop fibroids at a younger age. At least 25% of women have uterine fibroids which can cause problems. Many women with fibroids never have a problem and never know they have a fibroid.

Uterus – Womb

The uterus (womb) is a pear-shaped organ located in the lower part of a woman’s body. It is made up of the muscle wall, endometrium (lining), and the cervix (opening). In women who are not pregnant, the lining is shed monthly as part of the menstrual cycle (period). In women who are pregnant, the uterus is where a fetus will grow and develop.

Are there different types of fibroids (myomas)?

A fibroid can be very small, the size of a seed, or large, the size of a grapefruit. The medical term for a fibroid is leiomyoma or myoma. A woman may have one fibroid or many. A fibroid may be inside the uterus (submucosal), outside the uterus (subserosal), or in the wall of the uterus (intramural). Most fibroids grow in the wall of the uterus. Fibroids can also grow out from the uterus on stalks called peduncles.

What causes myomas?

Fibroids begin when cells overgrow in the wall of the uterus. However, the cause of uterine fibroids is not known. Researchers have many ideas of what may cause fibroids, but none of these are seen as definite causes of fibroid tumors. Some of these ideas include:

• Fibroids may be genetic (runs in families).
• Female hormones, estrogen, and progesterone cause fibroids to grow.

Fibroids grow rapidly during pregnancy when hormone levels are high and shrink when anti-hormone medicine is used. Fibroids also stop growing or shrinking once a woman reaches menopause.

Can fibroids turn into cancer?

Fibroids are usually benign (not cancerous). Having fibroids does not increase a woman’s risk of developing cancer. In less than 1 in 1,000 cases a cancerous fibroid will occur. A cancerous fibroid is called leiomyosarcoma.

Who usually develops myomas?

Age, race, lifestyle, and genetics may play a part in the development of fibroids. Here are the few known risk factors:

• Having a family member with fibroids increases the risk. If a woman’s mother had fibroids, her risk of having fibroids is about 3 times higher than average.
• African-Americans are 2-3 times more likely to present with symptomatic (problems such as pain or bleeding) uterine fibroids and will often develop fibroids at a younger age than the rest of the population of women with uterine fibroids.
• Asian women have a lower incidence of symptomatic uterine fibroids.
• Obesity is associated with uterine fibroids. The risk of obese women developing fibroids is 2-3 times greater than women of average weight.
• Eating beef, red meat (other than beef), and ham has been linked with having uterine fibroids while eating green vegetables seems to protect women from developing fibroids.

What are the symptoms of fibroids?

For most women, fibroids do not cause symptoms. At least 25% of women who have uterine fibroids do have symptoms which may include:

• Heavy bleeding or painful periods
• Bleeding between periods
• Cramping
• Bloating of the lower belly (abdomen or pelvic area)
• Feeling of fullness in the pelvic area
• Pain during sex
• Low back pain
• Frequent urination

Fibroids can also cause infertility (being unable to get pregnant), miscarriages, or premature labor (labor before 37 weeks of pregnancy).

How do you know you have a fibroid?

You may not know if you have fibroids if they are not causing any problems. A health care provider may find a fibroid on a routine exam, or you may see your health care provider if you are having symptoms. The health care provider may:

• Do a physical exam of your uterus (pelvic exam) to check the size of your uterus (womb), and may feel the fibroid as a lump on your uterus during the pelvic exam.
• Send you for a procedure to get a “picture” of your uterus.
• Do blood tests to check your blood count for anemia (low iron in your blood due to heavy periods or bleeding between periods) or for other problems.

The pelvic exam and the tests help your health care provider find out if you have fibroids, where they are, and how large they are.

Diagnosis Methods for Uterine Fibroids

Your health care provider can do an imaging examination to produce a picture to confirm that you have fibroids. These might include:

• Ultrasound(US) – uses sound waves to produce a picture to see if you have fibroids. An ultrasound probe can be placed on the abdomen or it can be placed inside the vagina during the ultrasound.
• Magnetic Resonance Imaging(MRI) – magnets and radio waves are used to produce the picture.
• X-rays– uses a form of radiation to produce the picture.
• Cat Scan(CT) – takes many X-ray pictures of the body from different angles for a more complete picture.
• Hysterosalpingogram(HSG) <- an x-ray done by
• Sonohysterogram –an ultrasound test that uses saline and ultrasound to look at the uterus and pelvic area.

You might also need additional procedures to know for sure if you have fibroids. There are two types of procedures to do this:

• Diagnostic Laparoscopy or Gynecologic Laparoscopy– surgery in which the doctor makes a cut into the abdomen and inserts a thin lighted tube with a small camera attached. This allows the doctor to see inside the abdomen to look at the uterus, ovaries, and pelvic area.
• Hysteroscopy– The doctor passes a long, thin tube with a light through the vagina and cervix into the uterus. The hysteroscope has a light and camera attached to it so your doctor can see the inside of the uterus on a video screen.

Will I have trouble getting pregnant if I have myomas?

In some cases, fibroids are severe enough to prevent a woman from becoming pregnant (infertility). If a woman is pregnant, fibroids can cause problems (complications) during pregnancy, labor, and delivery. Since fibroids are controlled by hormone levels they grow rapidly during pregnancy. Hormone levels are high during pregnancy.

What kinds of problems will fibroids cause in pregnancy?

The most common complications caused by fibroids during pregnancy are:

• Labor does not progress – this can happen if the uterus (womb) does not contract as it should and the baby does not move out through the birth canal to be born.
• Baby is breech – the baby is coming out bottom first. The usual position of a baby is for the head to come out first, but breech babies are in the bottom or feet-first position.
• Placenta abruption – the placenta pulls away from the uterus (womb) before delivery.
• Preterm delivery – the baby is born before 37 weeks of pregnancy.
• Cesarean section (C-section)- a cut (incision) is made in the mother’s abdomen (belly) and uterus (womb) and the baby is lifted out.