Uterine fibroids at a glance
- Uterine fibroids are benign (noncancerous) tumors found in or on a woman’s uterus.
- As many as 3 in 4 women will develop uterine fibroids by the time they are 50 years old, and the tumors often shrink or stop growing once a woman reaches menopause.
- Not every woman with uterine fibroids will experience infertility, but fibroids are present in about 5-10 percent of infertile women, according to the American Society for Reproductive Medicine (ASRM).
- Infertility due to fibroids may be caused by impaired blood flow, changes in the size and shape of the cervix or uterus, and blocked fallopian tubes.
- The exact cause of uterine fibroids is unknown, but they may be linked to hormone levels and genetic predisposition.
- Uterine fibroids often cause no symptoms or cause symptoms such as heavy menstrual bleeding, pressure and pain in the abdomen, frequent urination, constipation and painful sexual intercourse.
- Treatments for uterine fibroids range from progesterone-based medication to surgery.
What are uterine fibroids?
Uterine fibroids are firm, noncancerous growths that can develop on the inner or outer wall of a woman’s uterus. Also known as leiomyomas or myomas, uterine fibroids are not associated with an increased risk of gynecologic cancer.
Fibroid growth, quantity and size vary greatly. Some tumors may be too small for the human eye to see, others may be large enough to expand and distort the uterus. While uterine fibroids are typically not found outside of the pelvic cavity area, they can appear on a woman’s cervix or attached to organs near the uterus, such as the bowel or bladder. Types of uterine fibroids include:
Subserosal fibroids are attached to the outside of the uterine wall and make up about 55 percent of fibroid cases.
Intramural fibroids grow within the muscle layer of the uterine wall and are responsible for about 44 percent of fibroid cases.
Submucosal fibroids are found in the uterine cavity and cause about 5 percent of fibroid cases.
Uterine fibroids are common in women of reproductive age. The Office on Women’s Health estimates that 20 to 80 percent of women will develop fibroids by the time they are 50 years old. However, not all women will experience symptoms and many will be unaware that they have fibroids unless a doctor discovers them during a pelvic exam or ultrasound.
Learn more about fibroids from the American Society for Reproductive Medicine’s video below.
Uterine fibroids and infertility
Not every woman with fibroids will experience infertility. According to ASRM, about 5-10 percent of infertile women have uterine fibroids. When fibroids do result in infertility, they generally cause the following conditions:
- Changes in the size of the uterine cavity lining, affecting movement of sperm or making it difficult for the embryo to implant
- Changes in the shape of the cervix or uterus, also disturbing sperm or embryo movement
- Blocked fallopian tubes inhibiting sperm from reaching the eggs and an embryo from passing into the uterus
- Impaired blood flow to the uterine cavity, impeding an embryo’s implantation in the uterine lining for pregnancy.
Causes of uterine fibroids
The exact cause of uterine fibroids is unknown. Researchers believe that hormonal factors (estrogen and progesterone levels) play a role in the development of the tumors. Anti-hormone medications, such as leuprolide, that suppress a woman’s estrogen levels temporarily cause the fibroids to shrink. Additionally, fibroids will often grow rapidly during pregnancy but will stop developing when a woman reaches menopause, indicating a link to hormones.
Some women also have a family history of uterine fibroids, which indicates the possibility of a genetic predisposition to the tumors.
Risk factors for uterine fibroids
Researchers claim that several factors can increase a woman’s risk of developing fibroids.
Family history: According to the Office on Women’s Health, a woman is 3 times more likely to develop fibroids if her mother or another family member has had them.
Age: Fibroids are most common in women who are 30 to 50 years old. Women nearing menopause often have the highest risk for developing fibroids because of their lengthy estrogen exposure, but the tumors often shrink after menopause.
Obesity: Women who are obese are 2 to 3 times more likely to develop uterine fibroids.
Eating habits: Consuming large amounts of red meat and ham in particular are also linked to fibroid growth.
Early menstruation: If a woman experienced her first menstrual cycle before age 10, she is at higher risk.
Ethnicity: Certain ethnicities, such as women of African decent, are more likely to develop fibroids, although the exact genetic link is unknown.
Uterine fibroid symptoms
Many women do not experience symptoms from uterine fibroids. However, some cases are very painful. Uterine fibroids may be present if a woman has any of the following symptoms:
- Heavy menstrual bleeding, bleeding between periods and/or prolonged periods (seven days or more)
- Pressure or pain in the pelvis (caused by fibroid pressure on pelvic organs)
- Enlargement of and pressure in the lower abdomen
- Painful sexual intercourse
- Frequent urination from fibroid pressure on the bladder
- Lower back pain.
Uterine fibroids diagnosis & treatment
Uterine fibroids are commonly found during routine pelvic exams when the doctor feels an irregularity in the shape of the uterus. The doctor may order an imaging test such as an ultrasound, X-ray, CT scan or MRI to confirm the presence of fibroids.
Other imaging techniques may include a hysterosalpingogram, a specialized X-ray in which dye is placed in the uterus to see how it moves through the fallopian tubes. The physician may also request a sonohysterogram, a unique ultrasound in which a salt solution is used to expand the uterus to check for fibroids within the endometrial cavity.
The evidence found through testing, such as the size and location of the fibroids, will determine the patient’s treatment plan. The doctor will also take into account the woman’s age, health and medical history, her tolerance for medications and procedures, and her desire to bear children in the future.
Medications for uterine fibroids
Doctors may prescribe women with mild fibroid symptoms low-dose birth control pills, progesterone injections or an intrauterine device (IUD) with small amounts of progesterone-like medication.
Other medications are called gonadotropin releasing hormone agonists (GnRHa) and can help shrink fibroids. GnRHa medications are often prescribed prior to surgery to make fibroids easier to remove. Side effects can include:
- Hot flashes
- Decreased sex drive
- Joint pain.
Surgery for uterine fibroids
Surgery is often recommended to women who have moderate or severe symptoms from uterine fibroids. There are several surgical options to remove fibroids:
Hysterectomy removes the uterus and is the only way to cure uterine fibroids unconditionally. A physician may recommend hysterectomy if the woman is nearing or past menopause, has large fibroids, experiences unusually heavy menstrual bleeding or does not want children.
Myomectomy removes fibroids without disrupting the healthy uterine tissue and is suggested for women who want children in the future. Myomectomy can be performed through an incision in the abdomen. Depending on the size of the fibroids, it may also be performed as a minimally invasive surgery with laparoscopy. This utilizes special instruments and a thin, lighted tube with camera inserted through a small incision that provides a view of the uterus. A hysteroscopy is a similar procedure that accesses the uterus through the vagina.
Endometrial ablation destroys the lining of the uterus using wire, boiling water, electric current, laser or freezing. Approximately half of the women who undergo endometrial ablation no longer have menstrual bleeding. This is typically an outpatient procedure with few risks. However, a woman will no longer be able to bear children.
Uterine fibroid embolization (UFE) inserts a thin tube into the blood vessels that supply blood to a fibroid. Tiny plastic or gel particles are injected into the blood vessel to block the supply to the fibroid, causing it to shrink. While not all fibroids can be treated with UFE, doctors typically recommend the procedure for women who do not want a hysterectomy or who have fibroids that are causing heavy bleeding, pain and pressure. UFE may make it impossible for a woman to have children.
Myolysis uses electric currents or freezing to destroy fibroids by inserting a needle, directed by a laparoscope, into the tumor.