Fibroids are non-cancerous (benign) tumors that grow from the muscle layers of the uterus (womb). They are also known as uterine fibroids, leiomyomas, or myomas.
Fibroids are growths of smooth muscle, and can vary from the size of a bean to as large as a melon.
In this article, we will cover the causes, symptoms, diagnosis, and treatment of fibroids.
Fast facts on fibroids
Here are some key points about fibroids. More detail and supporting information is in the main article.
What are fibroids?
Fibroids affect at least 20 percent of all women at some point in their life. Women of reproductive age are the most likely to develop them. Also, overweight and obese women have a significantly higher risk of developing fibroids, compared with women of normal weight.
Four types of fibroids
There are four types of fibroids, characterized by their location in the uterus:
- Intramural - located in the wall of the uterus, this is the most common type.
- Subserosal fibroids - located outside the wall of the uterus but underneath the tissue layer that surrounds the uterus. They can develop into pedunculated fibroids (stalks) and become quite large.
- Submucosal fibroids - located in the muscle beneath the lining of the uterus wall. This type can protrude into the cavity of the uterus.
- Cervical fibroids - located in the neck of the womb (the cervix).
Causes of fibroids
Caffeine may increase the risk of fibroids.
Experts cannot come to a common consensus about why fibroids occur.
During a woman's reproductive years, estrogen and progesterone levels are high. When estrogen levels are high, especially during pregnancy, fibroids tend to swell. When estrogen levels are low, fibroids may shrink, for example, during a woman's menopause.
Heredity may also be a factor; women whose close relatives have had fibroids have a higher risk of developing them.
There is also some evidence that red meats, alcohol, and caffeine could increase the risk of fibroids. Also, an increased intake of fruit and vegetables might reduce the risk.
Symptoms of uterine fibroids
Most women have no symptoms, but around 1 in 3 will experience symptoms, which may include:
- Anemia (as a result of heavy periods)
- Discomfort in the lower abdomen (especially if fibroids are large)
- Frequent urination
- Heavy, painful periods
- Pain in the legs
- Painful sex
- Swelling in the lower abdomen (especially if fibroids are large)
Other possible symptoms of uterine fibroids include:
- Labor problems
- Pregnancy problems
- Fertility problems
- Repeated miscarriages
Diagnosis of fibroids
An ultrasound scan can often be used to diagnose fibroids.
In most cases, the symptoms of fibroids are rarely felt, and the patient does not know she has them. They are usually discovered during a vaginal examination.
- Ultrasound - can detect fibroids and eliminate other possible conditions which may have similar symptoms. An ultrasound can be used over the abdomen or transvaginally (a small probe is inserted into the vagina). This may help visualize cervical and submucosal types better.
- MRI - this is the best type of imaging to determine the size of fibroids and if there are multiple fibroids in the uterus. However, MRI can be quite expensive.
- Hysteroscopy - a small telescope to examine the inside of the uterus. During this procedure, if necessary, a biopsy (small tissue sample) can be taken of the lining of the uterus.
- Laparoscopy - a laparoscope is a small flexible tube used to examine the outside of the uterus. During this procedure, if necessary, a biopsy can be taken from the outer layer of the uterus. This is a surgical procedure that would require cutting through the skin.
Treatments for fibroids
If the woman has no symptoms and the fibroids are not affecting her day-to-day life, she may receive no treatment at all. Even women who have heavy periods but whose lives are not badly affected by this symptom may also opt for no treatment.
During menopause, fibroids usually shrink, and symptoms will often become less apparent, or disappear altogether.
When treatment is necessary, it may be in the form of medication or surgery.
Treating fibroids with medicationGnRHA injection
GnRHA (gonadotropin-releasing hormone agonist) makes the woman's body produce much lower quantities of estrogen, which shrinks the fibroids. GnRHA stops the menstrual cycle but does not affect fertility once treatment stops.
GNRHAs can cause menopause-like symptoms, including hot flashes, a tendency to sweat more, and vaginal dryness.
Although thinning of the bones (osteoporosis) is a possible side-effect, it is rare.
GnRHAs may be administered to the patient before surgery in order to shrink the fibroids. GNRHAs are for short-term use only.
Other drugs may be used, but they are less effective for larger fibroids; these include:
- Anti-inflammatory drugs - including mefenamic and ibuprofen. Anti-inflammatory medications reduce the production of prostaglandins, which are normally associated with heavy periods. Anti-inflammatory drugs are also painkillers. They do not affect fertility.
- The contraceptive pill - oral contraceptives help regulate the ovulation cycle, and may help reduce heavy menstrual bleeding associated with fibroids when a woman is on her period.
- LNG-IUS (Levonorgestrel intrauterine system) - a plastic device is placed inside the uterus. LNH-IUS releases levonorgestrel (progestogen hormone). The hormone stops the lining of the uterus from growing too fast, which reduces bleeding. One of the side-effects is irregular bleeding for up to 6 months, headaches, breast tenderness, and acne. In very rare cases, it can stop periods.
Surgery to treat fibroids
Depending on symptoms and whether medical therapy has failed, the patient may have to undergo surgery. The following surgical procedures may be considered:
- Hysterectomy - removing the uterus. This is only considered if the fibroids are very large, or if the patient is bleeding too much. Hysterectomies are sometimes an option to prevent fibroids coming back. Hysterectomy side effects include reduced libido and early menopause (if they also remove the ovaries and fallopian tubes during the surgery).
- Myomectomy - fibroids are surgically removed from the wall of the uterus. This option is more popular for women who want to get pregnant. Women with large fibroids, or fibroids located in particular parts of the uterus, may not be able to benefit from this surgery.
- Endometrial ablation - removing the lining of the uterus. This procedure may be used if the patient's fibroids are near the inner surface of the uterus; it is considered an effective alternative to a hysterectomy.
- UAE (Uterine artery embolization) - this treatment cuts off the fibroid's blood supply, effectively shrinking the fibroid. A chemical is injected through a catheter into a blood vessel in the leg, guided by X-ray scans.
- Magnetic-resonance-guided percutaneous laser ablation - an MRI scan is used to locate the fibroids. Then, very fine needles are inserted through the patient's skin and pushed until they reach the targeted fibroids. A fiber-optic cable is inserted through the needles. A laser light goes through the fiber-optic cable and shrinks the fibroids.
- Magnetic-resonance-guided focused ultrasound surgery - an MRI scan locates the fibroids, and sound waves are used to shrink the fibroids.
Most experts say magnetic-resonance-guided percutaneous laser ablation and magnetic-resonance-guided focused ultrasound surgery are both effective - however, there is some uncertainty regarding their benefits vs. risks.
Complications associated with fibroids
It is important to stress that in the vast majority of cases, fibroids do not result in complications for patients. However, for a tiny minority, they do. Complications may include:
- Menorrhagia (heavy periods) - the most common complication is a disruption of the woman's ability to function normally when periods are present, and also the possibility of depression because of this. In some cases, menorrhagia can lead to anemia and fatigue.
- Abdominal pains - if the patient's fibroids are large, she may experience swelling and discomfort in the lower abdomen. She may also have a sensation of being constipated. Some women with large fibroids say their bowel movements are painful.
- Premature birth, labor problems, miscarriages - as estrogen levels rise significantly during pregnancy, and as estrogen can speed up fibroid growth, some women may experience early labor, miscarriages, or complications during labor.
- Infertility - in some cases, fibroids can make it more difficult for the fertilized egg to attach itself to the lining of the uterus. A fibroid that grows outside the uterus (submucosal fibroid) may change the uterus' shape, making it harder for the woman to get pregnant.
- Leiomyosarcoma - this is extremely rare. This is a form of cancer, and it can develop inside the fibroids.