Uterine Leiomyoma

Uterine leiomyoma, commonly known as fibroids, are noncancerous growths that develop in or on the uterus and affect millions of women during their reproductive years. While many women experience no symptoms, others face significant challenges including heavy bleeding, pain, and complications affecting their quality of life.

fibroids, uterine fibroids, leiomyomas, myomas, uterine myomas

• Uterus
• Myometrium (uterine muscle wall)

Table of contents

• What Are Uterine Leiomyomas
• Types and Locations
• Who Gets Uterine Leiomyomas
• Symptoms and When They Occur
• Causes and Risk Factors
• Diagnosis
• Treatment Options
• Living With Uterine Leiomyomas

What Are Uterine Leiomyomas

Uterine leiomyomas are benign (noncancerous) tumors that grow in or on the wall of the uterus^[1]. These growths are made up of muscle and fibrous tissue that originate from the smooth muscle cells in the myometrium, which is the muscular layer of the uterus^[2]. They are the most common benign tumors in women and the most common noncancerous tumor in females overall^[2].

Fibroids can vary dramatically in size. Some are so tiny they can only be seen under a microscope, while others can grow as large as a grapefruit or even bigger^[1]. For comparison, fibroids can be as small as a seed or as large as a watermelon^[2]. You can have just one fibroid or multiple fibroids at the same time. In extreme cases, very large fibroids can fill the pelvis or stomach area and make a person look pregnant^[1].

Most importantly, fibroids are not cancerous and they almost never turn into cancer^[1]. They are not linked with a higher risk of other types of cancer in the uterus either^[1]. The transformation into cancer occurs in less than 1% of patients^[7].

Types and Locations

Uterine fibroids are classified based on where they grow in or on the uterus. There are several main types^[2]:

• Intramural fibroids are the most common type. These are embedded within the muscular wall of the uterus^[2].
• Submucosal fibroids grow just under the inner lining of the uterus and project into the uterine cavity^[2]. Some may extend into the uterine cavity or even prolapse through the cervix^[7].
• Subserosal fibroids develop on the outer surface of the uterus, under the outer lining. They can become quite large and grow outward into the pelvis^[2].
• Pedunculated fibroids are the least common type. These attach to the uterus with a narrow stalk or stem, looking somewhat like a mushroom^[2].

The symptoms and treatment options for fibroids are affected by their size, number, and location^[4].

Who Gets Uterine Leiomyomas

Fibroids are extremely common. Studies show that approximately 40% to 80% of people with a uterus have fibroids^[2]. By age 50, they can be detected in up to 80% of women^[4]. In the United States, the prevalence by age 50 is approximately 70% in White women and 80% in Black women^[7].

Fibroids most often occur in people between 30 and 50 years old^[2]. They usually develop during a woman’s reproductive years, from around age 16 to 50, when hormone levels are at their highest^[5]. Fibroids are rare in women under age 20^[6]. People who haven’t had their first period yet typically don’t have fibroids, and they’re also less common in people who’ve entered menopause^[2].

Women of African descent are more likely to develop fibroids. They are thought to develop more frequently in women of African-Caribbean origin^[5]. Compared with white women, Black women have a higher lifetime prevalence of fibroids and more severe symptoms, which can affect their quality of life^[4].

Symptoms and When They Occur

Many women with uterine fibroids don’t have any symptoms at all. As many as 1 in 3 women are unaware they have fibroids because they cause no symptoms^[5]. You might only discover you have them during a routine pelvic exam or pregnancy ultrasound^[1]. However, 25% to 30% of women experience significant symptoms^[3].

When symptoms do occur, they can include^[2]:

• Excessive or painful bleeding during your period, sometimes with blood clots
• Heavy menstrual bleeding and periods that last longer than normal
• Bleeding between your periods
• Pelvic cramping or pain with periods
• A feeling of fullness or pressure in your lower belly or bloating
• Frequent urination (this happens when a fibroid puts pressure on your bladder)
• Pain during sex
• Low back pain
• Constipation or feeling pressure on your rectum
• Long-term vaginal discharge
• Inability to urinate or completely empty your bladder
• Increased abdominal enlargement, causing your abdomen to look pregnant

The symptoms of uterine fibroids usually stabilize or go away after you’ve gone through menopause because hormone levels decline within your body^[2]. Fibroids tend to shrink when hormone levels are low, such as after menopause when a woman’s monthly period stops^[5].

Causes and Risk Factors

No one knows exactly what causes fibroids^[6]. However, they have been linked to the hormone estrogen, which is the female reproductive hormone produced by the ovaries^[5]. Fibroids are benign tumors that originate from the uterine smooth muscle tissue whose growth is dependent on estrogen and progesterone^[4]. The growths arise from uterine smooth muscle cells and grow primarily in response to estrogen^[3].

Several factors can increase or decrease your risk of developing fibroids^[4]:

Factors that increase risk:

• Age greater than 40 years (until menopause)
• African descent
• Early menarche (younger than 10 years)
• Family history of uterine fibroids
• No previous pregnancies
• Obesity

Factors that decrease risk:

• Having had children
• Late menarche (older than 16 years)
• Smoking
• Use of oral contraceptives

It’s thought that fibroids occur more often in overweight or obese women because being overweight increases the level of estrogen in the body^[5]. Women who have had children have a lower risk of developing fibroids^[5].

Diagnosis

Fibroids are often discovered by chance during a routine pelvic exam. During this exam, your doctor may feel irregular changes in the shape of your uterus, suggesting the presence of fibroids^[8]. Fibroids are classically diagnosed on physical exam and ultrasound imaging, which is highly sensitive for this condition^[3].

If your doctor thinks you may have fibroids, they’ll usually refer you for an ultrasound scan to confirm the diagnosis^[5]. Ultrasonography is the preferred initial imaging modality for diagnosis^[4]. This test uses sound waves to create a picture of your uterus. It can confirm that you have fibroids and map and measure them^[8].

There are two types of ultrasound that may be used^[8]:

• Transabdominal ultrasound: The ultrasound device is moved over your stomach area
• Transvaginal ultrasound: The device is placed inside your vagina to get images of your uterus

If you have irregular menstrual bleeding, you may need blood tests to look for possible causes. These might include a complete blood count to check for anemia (low iron levels in the blood) due to ongoing blood loss^[8].

Other imaging tests that may be used include^[8]:

• Hysterosonography: A thin, flexible tube is placed in the uterus and salt water is injected to get better ultrasound images of the inside of the uterus
• MRI (Magnetic Resonance Imaging): Uses powerful magnets and radio waves to create detailed pictures
• Hysteroscopy: A long, thin tube is inserted through the vagina and into the uterus to examine the inside

Treatment Options

The type of treatment depends on your age, general health, symptoms, type of fibroids, whether you are pregnant, and if you want children in the future^[6]. Management should be tailored to the size and location of fibroids, the patient’s age, symptoms, desire to maintain fertility, and access to treatment^[4].

Watchful Waiting

If you have fibroids but no symptoms, treatment may not be necessary. Expectant management is recommended for asymptomatic patients because most fibroids decrease in size during menopause^[4]. You may have follow-up pelvic exams or ultrasounds to check the fibroid’s growth^[6].

Medications

Various medicines can help control symptoms^[6]:

• Hormonal contraceptives: Birth control pills can help control heavy periods^[4]
• Intrauterine devices (IUDs): Devices that release hormones to help reduce heavy bleeding and pain^[6]
• Tranexamic acid: Helps reduce blood loss by helping your blood to clot. These tablets are taken 3 or 4 times a day during your period^[12]
• Nonsteroidal anti-inflammatory drugs (NSAIDs): Such as ibuprofen and naproxen, for pain relief^[4]
• Gonadotropin-releasing hormone agonists (GnRHas): These hormones are given by injection and work by stopping the ovaries from producing estrogen, which can help shrink fibroids^[12]. They are often used for a short time before surgery

Iron supplements may be prescribed to prevent or treat anemia due to heavy periods^[6].

Surgical and Procedural Treatments

Several surgical options are available^[6]:

• Hysteroscopy: This procedure can remove fibroids growing inside the uterus^[6]
• Myomectomy: Surgical removal of fibroids while preserving the uterus. This can be done through various approaches including laparoscopic (small incisions) or robotic-assisted methods^[14]. An estimated 15% to 33% of fibroids recur after myomectomy^[4]
• Hysterectomy: Removal of the uterus. Fibroids are the leading indication for hysterectomy, accounting for 39% of all hysterectomies performed annually in the United States^[4]
• Uterine artery embolization: A noninvasive procedure where small particles are injected into the bloodstream around the fibroid to cut off its blood supply, causing it to shrink^[14]
• Endometrial ablation: This procedure is sometimes used to treat heavy bleeding associated with fibroids, and works best when fibroids are small^[6]

In women undergoing hysterectomy for treatment, the least invasive approach possible should be chosen^[4].

Living With Uterine Leiomyomas

If you have symptoms from fibroids, there are several self-care measures you can take to help manage your condition and improve your quality of life.

Managing Pain and Discomfort

To help ease painful periods and fibroid-related discomfort^[15]:

• Apply a hot water bottle or heating pad on your lower stomach. This can improve blood flow and relax your muscles. Warm baths may also help relieve pain
• Lie down and rest. Place a pillow under your knees when lying on your back. If you prefer to lie on your side, pull your knees up toward your chest. These positions help take the pressure off your back
• Take over-the-counter pain relievers such as ibuprofen, naproxen, or acetaminophen. Try starting these medicines 1 to 2 days before your period begins^[15]

Diet and Nutrition

Maintaining a healthy diet can ease common symptoms. A diet rich in fruits like apples and tomatoes, and vegetables like broccoli and cabbage, could lower the risk of developing fibroids^[22]. Consider these dietary recommendations^[20]:

• Eat plenty of fiber-rich foods, including fruits, vegetables, and whole grains
• Include foods rich in omega-3 fatty acids, such as fish, flaxseeds, and walnuts
• Limit processed foods, red meats, and high-fat dairy products
• Reduce sugar intake, as a high-sugar diet could be linked to a higher risk of fibroids^[22]
• Limit alcohol and caffeine, as these can make symptoms worse^[22]

Eating plenty of fiber can help keep you regular so you do not have to strain during bowel movements^[15].

Physical Activity and Weight Management

Get regular exercise. Exercise helps improve blood flow and triggers your body’s natural painkillers, called endorphins^[15]. One study found that women who exercised the most (about 7 hours per week of activities like running, dancing, or walking) had the lowest chance of developing fibroids^[22]. Exercise can also help keep your blood pressure down^[22].

Maintaining a healthy weight will help improve your overall health^[15]. Keeping a healthy weight can help regulate hormone levels, as excess body fat can lead to higher estrogen levels^[20].

Stress Management

While researchers are still examining the impact of stress on fibroids, some studies suggest the two may be linked. Try relaxation techniques like^[22]:

• Muscle relaxation
• Deep breathing
• Visualization
• Biofeedback
• Yoga

Some women find that acupuncture helps ease painful periods^[15].

When to Contact Your Doctor

Contact your healthcare provider if you have^[15]:

• Heavy bleeding
• Increased cramping
• Bleeding between periods
• Fullness or heaviness in your lower belly area

If self-care for pain does not help, talk with your provider about other treatment options^[15].