Key Takeaways
- Extremely common: Up to 80% of women develop fibroids by age 50, and approximately 25-50% experience symptoms
- Most are benign: Uterine fibroids are almost always non-cancerous; the risk of a fibroid being cancerous (leiomyosarcoma) is estimated at less than 1 in 1,000
- Treatment is individualized: Options range from watchful waiting to medication to minimally invasive procedures to surgery
- Fertility can be preserved: Many treatment options maintain the ability to conceive, and most women with fibroids can have successful pregnancies
- African American women are disproportionately affected: They are 2-3 times more likely to develop fibroids and often experience more severe symptoms at younger ages
Overview
Uterine fibroids (also called leiomyomas or myomas) are non-cancerous growths that develop in or on the muscular wall of the uterus. They are the most common benign tumors in women of reproductive age, affecting an estimated 26 million women in the United States alone.
Fibroids vary tremendously in size, from microscopic seedlings to large masses that can distort and enlarge the uterus. A single uterus may contain one fibroid or dozens. According to clinical data, fibroids are the leading indication for hysterectomy in the United States, with approximately 200,000-300,000 hysterectomies performed for fibroids annually.
The economic impact is substantial. Fibroids cost the U.S. healthcare system an estimated $9.4 billion annually in direct medical costs, and indirect costs (lost work days, decreased productivity) may be even higher.
Types of Uterine Fibroids
Classification by Location
| Type | Location | Typical Symptoms |
|---|---|---|
| Intramural | Within the muscular uterine wall (most common) | Heavy periods, pelvic pressure, enlarged uterus |
| Submucosal | Just beneath the inner uterine lining | Heavy bleeding, fertility issues, even when small |
| Subserosal | On the outer surface of the uterus | Pelvic pressure, urinary frequency, back pain |
| Pedunculated | Attached to the uterus by a stalk | Can twist and cause acute pain |
| Cervical | In the cervix | Uncommon; may cause bleeding or urinary symptoms |
Classification by Size
- Small: Less than 2 cm (about the size of a seed or pea)
- Medium: 2-5 cm (about the size of a grape to a golf ball)
- Large: Greater than 5 cm (about the size of a lemon or larger)
- Very large: Greater than 10 cm (about the size of a grapefruit or larger)
Degeneration Types
Fibroids can undergo degenerative changes when they outgrow their blood supply:
- Hyaline degeneration: Most common type; usually asymptomatic
- Cystic degeneration: Fibroid develops fluid-filled areas
- Red (carneous) degeneration: More common in pregnancy; causes acute pain
- Calcific degeneration: Typically in postmenopausal women; calcium deposits replace fibroid tissue
Symptoms
Common Symptoms
Not all fibroids cause symptoms. When symptoms do occur, they depend largely on the size, number, and location of the fibroids:
- Heavy or prolonged menstrual bleeding: The most common symptom, affecting approximately 50% of symptomatic women; can lead to anemia
- Pelvic pressure or fullness: A feeling of heaviness in the lower abdomen
- Frequent urination: Caused by fibroids pressing on the bladder
- Difficulty emptying the bladder: Large fibroids can obstruct urinary flow
- Constipation: Fibroids pressing on the rectum can cause bowel difficulties
- Backache or leg pain: Particularly with posterior fibroids
- Pain during intercourse: Especially with fibroids near the cervix
- Reproductive problems: Difficulty conceiving, recurrent miscarriages, or complications during pregnancy
Symptom Severity
Approximately 25-50% of women with fibroids experience symptoms significant enough to affect their daily lives. The severity often correlates with fibroid size and location rather than the total number of fibroids.
Asymptomatic Fibroids
Many fibroids are discovered incidentally during routine pelvic examinations or prenatal ultrasounds. Small, asymptomatic fibroids typically do not require treatment but should be monitored.
Causes and Risk Factors
Known Risk Factors
| Factor | Details |
|---|---|
| Age | Most common between ages 30-50; shrink after menopause |
| Race | African American women: 2-3x higher risk, earlier onset, more severe disease |
| Family history | Having a mother or sister with fibroids increases risk 3x |
| Obesity | Risk increases 2-3x with obesity (BMI >30) |
| Early menstruation | Starting periods before age 10-11 increases risk |
| Nulliparity | Never having given birth increases risk |
| Vitamin D deficiency | Associated with increased fibroid risk |
| Diet | High red meat and low green vegetable consumption may increase risk |
Hormonal Influence
- Estrogen and progesterone promote fibroid growth; this is why fibroids typically grow during reproductive years and shrink after menopause
- Fibroids have more estrogen and progesterone receptors than normal uterine muscle cells
- Pregnancy often causes fibroid enlargement due to high hormone levels
- Hormone therapy after menopause may cause fibroids to persist or grow
Protective Factors
- Pregnancy and childbirth: Each full-term pregnancy reduces fibroid risk
- Long-term oral contraceptive use: May reduce risk
- Physical activity: Regular exercise is associated with reduced risk
- Adequate vitamin D: Sufficient vitamin D levels are associated with lower risk
Diagnosis
Clinical Evaluation
- Medical history: Symptoms, menstrual patterns, family history
- Pelvic examination: May reveal an enlarged or irregularly shaped uterus
- Symptom assessment tools: Standardized questionnaires such as the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire
Imaging Studies
| Modality | Purpose | Accuracy |
|---|---|---|
| Transvaginal ultrasound | First-line imaging for fibroids | Detects fibroids as small as 0.5 cm |
| Pelvic ultrasound | Non-invasive screening | Good for overall uterine size assessment |
| Saline infusion sonography (SIS) | Better visualization of submucosal fibroids | Detailed mapping of endometrial cavity |
| MRI | Precise fibroid mapping and characterization | Gold standard for pre-treatment planning |
| Hysteroscopy | Direct visualization of uterine cavity | Diagnostic and therapeutic for submucosal fibroids |
Laboratory Tests
- Complete Blood Count (CBC): To check for anemia from heavy bleeding
- Iron studies: To assess iron deficiency
- Thyroid function tests: To rule out thyroid-related causes of heavy bleeding
- Pregnancy test: To rule out pregnancy-related causes
Treatment Options
Watchful Waiting
For small, asymptomatic fibroids:
- Regular monitoring with pelvic exams and ultrasound
- No intervention needed unless symptoms develop or fibroids grow
- Many fibroids stabilize or shrink over time, especially approaching menopause
Medications
| Medication | How It Works | Considerations |
|---|---|---|
| NSAIDs (ibuprofen, naproxen) | Reduce pain and inflammation | First-line for mild pain; do not shrink fibroids |
| Tranexamic acid (Lysteda) | Reduces heavy menstrual bleeding | Taken only during period; non-hormonal |
| Oral contraceptives | Regulate bleeding | May help control bleeding; limited effect on fibroid size |
| Levonorgestrel IUD (Mirena) | Reduces menstrual bleeding | Effective for bleeding; may not shrink fibroids significantly |
| GnRH agonists (leuprolide) | Temporary menopause; shrinks fibroids | Used short-term (3-6 months); significant side effects |
| GnRH antagonist (elagolix, relugolix) | Reduces bleeding and fibroid size | Newer FDA-approved options for heavy bleeding |
| Selective progesterone receptor modulators (ulipristal) | Modifies progesterone effects | Available in some countries; reduces bleeding and fibroid size |
Minimally Invasive Procedures
- Uterine Fibroid Embolization (UFE/UAE): Blocks blood supply to fibroids, causing them to shrink; approximately 85-90% of women experience significant symptom improvement
- MRI-guided Focused Ultrasound Surgery (MRgFUS): Uses focused ultrasound waves to heat and destroy fibroid tissue; non-invasive, no incisions
- Radiofrequency ablation: Uses heat energy to shrink fibroids; can be performed laparoscopically or transcervically (Acessa, Sonata)
Surgical Options
- Myomectomy: Surgical removal of fibroids while preserving the uterus; preferred for women who want to maintain fertility. Can be performed hysteroscopically (through the cervix, no incisions), laparoscopically, or through open abdominal surgery
- Hysterectomy: Complete removal of the uterus; the only definitive cure for fibroids. Appropriate for women who do not wish to preserve fertility
- Endometrial ablation: Destroys the uterine lining; effective for heavy bleeding but does not treat the fibroids themselves
Living With Fibroids
Daily Management Strategies
- Iron-rich diet: If experiencing heavy bleeding, consume iron-rich foods (spinach, red meat, beans) or take iron supplements as recommended
- Regular exercise: Physical activity may help reduce estrogen levels and improve symptoms
- Weight management: Maintaining a healthy weight can help reduce estrogen exposure
- Stress reduction: Chronic stress may exacerbate hormonal imbalances
- Pain management: Heat therapy, gentle stretching, and over-the-counter pain medications
- Track your symptoms: Monitor bleeding patterns, pain levels, and any changes to share with your healthcare provider
Dietary Considerations
- Some evidence suggests that a diet rich in fruits, vegetables, and whole grains may help reduce fibroid risk
- Limiting alcohol, caffeine, and red meat may be beneficial
- Ensuring adequate vitamin D intake (through sun exposure, diet, or supplements) is important, especially for women with deficiency
Pregnancy With Fibroids
Most women with fibroids have uncomplicated pregnancies. However, depending on fibroid size and location, there can be increased risks:
- Miscarriage: Slightly increased risk, particularly with submucosal fibroids
- Preterm delivery: Approximately 15-30% of women with large fibroids may deliver early
- Cesarean delivery: More likely if fibroids obstruct the birth canal
- Fibroid growth during pregnancy: Approximately 30-60% of fibroids grow during pregnancy, though many remain stable or shrink
- Postpartum hemorrhage: Slightly increased risk
When to See a Doctor
Seek Evaluation For:
- Heavy menstrual bleeding (soaking through pads/tampons every hour for 2+ hours)
- Periods lasting longer than 7 days
- Pelvic pain or pressure that affects daily activities
- Frequent urination or difficulty emptying your bladder
- Pain during intercourse
- Difficulty becoming pregnant
- Rapid increase in abdominal size
- Bleeding between periods
Seek Emergency Care For:
- Sudden, severe pelvic pain
- Very heavy bleeding with dizziness or lightheadedness
- Fever with pelvic pain
- Inability to urinate
Frequently Asked Questions
Do fibroids increase the risk of cancer?
Uterine fibroids are almost always benign. The risk of a fibroid being cancerous (leiomyosarcoma) is estimated at less than 0.1% (fewer than 1 in 1,000). However, any rapidly growing fibroid, especially after menopause, should be evaluated promptly by a healthcare provider to rule out malignancy.
Can I get pregnant if I have fibroids?
Yes. Most women with fibroids can conceive and have healthy pregnancies. The impact of fibroids on fertility depends on their size and location. Submucosal fibroids (those protruding into the uterine cavity) are most likely to affect fertility and may benefit from removal before attempting pregnancy. Intramural and subserosal fibroids have less impact on fertility unless they are very large.
Will my fibroids come back after treatment?
Fibroids can recur after treatment, with recurrence rates varying by the type of treatment. After myomectomy, approximately 20-25% of women experience regrowth within 5-10 years. Hysterectomy is the only treatment that eliminates fibroids permanently because it removes the uterus. Uterine fibroid embolization has a lower recurrence rate than myomectomy, but new fibroids can develop.
Do fibroids go away after menopause?
In most cases, fibroids shrink after menopause due to the natural decline in estrogen and progesterone. Studies show that approximately 40-60% of fibroids decrease in size after menopause. However, not all fibroids shrink, and some women continue to experience symptoms. Hormone replacement therapy (HRT) after menopause may prevent fibroids from shrinking or cause them to grow.
What is the best treatment for fibroids?
There is no single "best" treatment for fibroids. The optimal approach depends on multiple factors including the severity of symptoms, size and location of fibroids, your age, desire for future fertility, and personal preferences. A healthcare provider specializing in fibroid management can help you weigh the benefits and risks of each option.
Can diet and lifestyle changes shrink fibroids?
While no specific diet has been proven to shrink existing fibroids, certain lifestyle modifications may help manage symptoms and potentially slow growth. Maintaining a healthy weight, exercising regularly, ensuring adequate vitamin D intake, and eating a diet rich in fruits and vegetables may all contribute to better fibroid management. These approaches work best in combination with, not as a replacement for, medical treatment.