Uterine fibroids (also called myomas or leiomyomas) are benign (non-cancerous) tumors of muscle tissue that can enlarge and/or distort the uterus (womb) and sometimes the cervix. They start from the smooth muscle cells in the wall of the uterus.
Fibroids are usually found as multiple tumors. It is estimated that uterine fibroids will affect 8 in 10 African American women and 7 in 10 Caucasian women by the time they reach menopause. Fibroids usually become noticeable during the reproductive years and become smaller after menopause. Most cause no symptoms and do not require treatment. However, depending on their size and location in the uterus, they may cause symptoms and require treatment.
Causes of Fibroids
Fibroids happen when a genetically altered single muscle cell in the wall of the uterus multiplies rapidly to form a tumor. The exact cause of fibroids is unclear, but evidence suggests that both genetics and hormones play roles. Estrogen (a hormone produced primarily by the ovaries) may stimulate growth of fibroids. After menopause, when estrogen levels are low, fibroids rarely grow and frequently shrink. Their growth and development may also be influenced by progesterone, a hormone produced by the ovary after ovulation and during pregnancy. There is no evidence that any nutritional or lifestyle factors affect fibroid growth and development. Similarly, medications such as low-dose birth control pills have little or no impact on fibroid growth.
Location of fibroids
Fibroids are usually found in or around the body of the uterus, but sometimes occur in the cervix (neck of the uterus). Fibroids within the uterus can be divided into three categories: subserosal, located in the outer wall of the uterus (55%), intramural, found in the muscular layers of the uterine wall (40%) and submucosal, which protrude into the uterine cavity (5%). Fibroids can be connected to the uterus through a stalk (pedunculated) or can be attached to nearby organs such as the bladder and bowel, or to the ligaments surrounding the uterus. Fibroids are rarely found outside the pelvic cavity.
Symptoms from fibroids
Symptoms from fibroids are related to their size and location. Most women with uterine fibroids have no symptoms. The most common symptoms are abnormal uterine bleeding, pain and pelvic pressure.
Abnormal uterine bleeding
Abnormal uterine bleeding is the most common symptom associated with fibroids located in or near the lining of the uterus and is the main reason for requesting treatments. Because abnormal uterine bleeding can result from other causes such as endometrial cancer and hormonal problems, it is important that women with fibroids who experience abnormal vaginal bleeding, receive a thorough evaluation for other causes of bleeding.
A rapidly enlarging fibroid may outgrow its blood supply and degenerate, causing pain and cramping. Fibroids which are attached to the uterus by a thin stalk may twist and cause severe pain. Large uterine fibroids may also make sexual intercourse or certain actions painful. Women with fibroids may also experience painful menstrual cramps.
Large fibroids may press on nearby pelvic organs. If the fibroid presses on the bladder, which lies in front of the uterus, urinary frequency or urgency may occur. Pressure on the ureters, the tubes that transport urine from the kidneys to the bladder can result in kidney damage if the fibroids are not removed. Fibroids in the lower uterus may put pressure on the large bowel and rectum which could cause painful bowel movements, constipation, hemorrhoids, or altered shape of stools.
Uterine fibroids are often diagnosed by pelvic exam. During this examination, fibroids may be determined by assessing the shape and size of the uterus. Further imaging studies like ultrasound, may be utilized to confirm this finding. Sometimes a pelvic exam alone may not be enough to distinguish a fibroid from an ovarian mass close to the uterus.
Ultrasound uses the echoes from high frequency waves to create a picture of the pelvic organs. As fibroids vary in size and location, both transvaginal and transabdominal ultrasounds may be used to best see the fibroids.
Sonohysterography is an ultrasound procedure in which the uterine cavity is outlined by a small amount of fluid which is placed in the uterus through a thin plastic tube. Sonohysterography improves the doctor’s ability to identify fibroids which protrude into or distort the uterine cavity.
Fibroids and fertility
Uterine fibroids are common and they are found in 5-10% of infertile women. Certain types of fibroids are known to decrease fertility. They include fibroids that are inside they uterine cavity and very large fibroids (>6 cm in diameter) that are located within the wall of the uterus. Because most women with fibroids will not be infertile, they and their partners should have a thorough evaluation to detect other problems that can decrease fertility. A fertility specialist can help determine if fibroids might be hampering their ability to conceive.
There are several explanations why uterine fibroids may reduce fertility:
- Changes in the position of the cervix (the vaginal opening to the womb) due to fibroids located above it may affect the number of sperm that can travel through the cervix.
- Changes in the shape of the uterus can interfere with sperm movement.
- Blockage of the fallopian tubes by the fibroids.
- Affecting the blood flow to the uterine cavity where the embryo would implant.
- Changes in the uterine muscle that prevents movement of the sperm of the embryo.
Fibroids during pregnancy
Fibroids are found in 2% to 12% of pregnant women. Not all fibroids will increase in size and complicate a pregnancy. If a fibroid grows, it will typically do so in the first 12 weeks of pregnancy and sometimes shrink as the pregnancy continues. In some instances, fibroids can possibly outgrow their blood supply and cause severe pain that might lead to hospitalization. Also, fibroids can change the baby’s presentation (position at birth), increase the risk of cesarean cancer, miscarriage and preterm delivery. The management of uterine fibroids depends on your doctor’s recommendations. Rarely is surgery necessary or performed during pregnancy.
Cancers arising from uterine fibroids are called leiomyosarcomas. The overall risk of fibroids being cancerous (malignant) is approximately one in 1,000 (of removed fibroids) in the reproductive years and is more common in postmenopausal women. A fibroid that grows after menopause may be a leiomyosarcoma in which case removal of the uterus (hysterectomy) is required.
Fibroids and treatments
Fibroids usually do not require treatment because most patients with fibroids do not have symptoms. Women with fibroids should have regular checkups to determine if the fibroids are changing in size, to track worsening symptoms, and if planning to get pregnant.
If treatment is required
Since some fibroids are affected by estrogen levels, medical management of uterine fibroids may help temporarily but will not improve fertility. Medications that are used mat be associated with undesirable side effects. These medicines include gonadotropin-releasing hormone (GnRH) analogs (hot flashes. Vaginal dryness, mood changes, osteoporosis), birth control pills (breast tenderness, blood clots), progestin’s (bloating, abnormal bleeding), and androgens (unwanted hair growth). Alternative approaches such as herbal and homeopathic therapies have not been shown to improve symptoms caused by fibroids.
Surgery is considered when fibroids cause significant symptoms and should not be considered to treat infertility until after a thorough evaluation of other factors that could be causing infertility.
Surgical options available if desire future fertility
The only surgical option available to women who desire to get pregnant in the future is a myomectomy or surgical removal of the fibroids. In most cases, the size and location of the fibroids will determine the appropriate surgical technique.
The type of myomectomy performed (described below) depends on the location and size of the fibroids All myomectomies carry the risk of scarring and adhesions which can affect future fertility. Each also carried the risk of excessive bleeding, which may require a hysterectomy.
With this method, the surgeon makes an incision in the abdominal wall. It is most commonly used to remove tumors on the outer surface of the uterus and surrounding organs. This surgery usually requires a 24 to 72 hour hospital stay and 4-6 weeks recovery.
During operative laparoscopy, the doctor places a laparoscope into the abdomen through a small incision near the navel and then uses surgical instruments placed through small 5-10 mm incisions to remove the fibroids. Women can be sent home from the hospital; the same day or within 24 hours. Recovery time is usually two to seven days.
During this procedure, the doctor inserts a telescope through the cervix and fills the uterus with fluid to expand the walls. Surgical instruments are then inserted through a channel in the hysteroscope to remove submucous fibroids. Generally, women are sent home the same day as surgery and can return to their normal activities few days after the procedure. Serious complications are uncommon and include damage or scarring to the inside cavity of the uterus, electrolyte imbalance (changes in the minerals in the blood system), puncturing the uterus and bleeding.
Robotic assisted myomectomy
During a robotic procedure, a doctor places a telescope into the abdomen at or above the navel. Up to five other small incisions are made to hold the instruments to remove the fibroids. Women are typically sent home form the hospital the same day or within 24 hours. Recovery time is usually between a few days and a week.
Chance after a myomectomy that the uterine fibroids will return
This risk of recurrence is about 30% over 10 years. Patients with multiple fibroids are more likely to experience recurrence as compared to patients with solitary fibroids.
Another laparoscopic technique called myolysis involves burning the fibroids through heat energy via needles or lasers.
A method which does not involve an incision is called MRI-guided focused ultrasonic treatment (MrgFUS). As this is a relatively new technology, this is limited information about long-term outcomes. At this time, MrgFUS cannot be recommended for women hoping to maintain or improve their fertility.
Uterine artery embolization
Uterine artery embolization is a procedure performed by a radiologist that involves injecting small particles into the uterine blood vessels. These particles clog the small blood vessels that supply the fibroids, impeding the blood supply and causing these fibroids to degenerate. Patients generally experience several days of pain after the procedure. Fibroid volume shrinks by 40-50%, and the majority of patients experience symptomatic relief. At this time, it is not recommended for women desiring future fertility and pregnancy.
Approximately 50% of all hysterectomies are performed to treat uterine fibroids. If you have symptomatic fibroids and future pregnancy is not desired, a hysterectomy (surgical removal of the uterus) may be recommended. There are three ways to perform a hysterectomy: abdominally, vaginally and in some cases laparoscopically. Recovery time is usually two to six weeks. It is important to discuss with your doctor the potential implications of a hysterectomy including the sexual, psychological and medical consequences.
Uterine fibroids are common and can affect fertility in many ways. They can affect ovulation, fertilization and implantation. Treatment options vary, but treatment will help to address the gynecologic symptoms of fibroids and improve overall fertility. The management of uterine fibroids will depend upon the severity of your symptoms and your doctor’s recommendations.