Uterine Fibroids

Uterine fibroids, also known as leiomyomas or myomas, are non-cancerous growths that develop in or on the walls of the uterus. These benign tumors are remarkably common, affecting up to 80% of women by age 50, though many women may never experience symptoms. Fibroids can vary dramatically in size—from tiny seedlings undetectable by the human eye to large masses that can distort and enlarge the uterus. While the exact cause remains unclear, fibroids are hormone-dependent and tend to grow during reproductive years when estrogen and progesterone levels are higher. Understanding fibroids is crucial for women's health, as they can significantly impact quality of life through symptoms like heavy menstrual bleeding, pelvic pain, and reproductive challenges.

Medical Disclaimer: This information is for educational purposes only and should not replace professional medical advice. If you experience heavy bleeding, severe pain, or other concerning symptoms, consult your healthcare provider for proper evaluation and treatment.

Overview

Uterine fibroids are monoclonal tumors arising from the smooth muscle cells of the myometrium. Despite being called tumors, fibroids are benign with malignant transformation occurring in less than 0.1% of cases. They represent the most common pelvic tumor in women and are the leading indication for hysterectomy in the United States, accounting for approximately 200,000 procedures annually. The prevalence of fibroids increases with age during reproductive years, peaking in the 40s, and typically stabilizing or shrinking after menopause due to declining hormone levels.

Fibroids are classified based on their location within the uterus. Intramural fibroids, the most common type, grow within the muscular uterine wall. Subserosal fibroids project outward from the uterus and can sometimes be connected by a stalk (pedunculated). Submucosal fibroids bulge into the uterine cavity and, despite being the least common type, are most likely to cause heavy bleeding and fertility problems. Some fibroids may have characteristics of multiple types. The location, size, and number of fibroids largely determine the symptoms a woman experiences and the treatment options available.

The impact of fibroids extends beyond physical symptoms. They significantly affect quality of life, leading to missed work days, relationship strain, and psychological distress. The economic burden is substantial, with estimated annual costs exceeding $34 billion in the United States alone, including direct medical costs and indirect costs from lost productivity. Additionally, fibroids disproportionately affect Black women, who are 2-3 times more likely to develop fibroids, tend to develop them at younger ages, and often experience more severe symptoms. This racial disparity highlights the importance of culturally sensitive care and research into underlying genetic and environmental factors.

Symptoms

While many women with fibroids experience no symptoms at all, those who do may face a range of issues that can significantly impact daily life. Symptoms depend on the location, size, and number of fibroids.

Menstrual Symptoms

  • Heavy menstrual flow - The most common symptom
    • Soaking through pads/tampons every hour
    • Bleeding lasting more than 7 days
    • Passing large blood clots
    • Anemia from chronic blood loss
  • Painful menstruation - Dysmenorrhea
    • Cramping more severe than typical periods
    • Pain may start before bleeding
    • May require pain medication
  • Unpredictable menstruation - Irregular cycles
    • Cycles shorter than 21 days or longer than 35 days
    • Spotting between periods
    • Difficulty predicting period timing
  • Intermenstrual bleeding - Bleeding between periods

Pelvic Symptoms

Urinary Symptoms

  • Involuntary urination - Stress incontinence from pressure
    • Leaking with coughing or sneezing
    • Urgency incontinence
    • Difficulty emptying bladder completely
  • Frequent urination - Fibroids pressing on bladder
  • Nocturia - Waking at night to urinate
  • Difficulty starting urination
  • Feeling of incomplete bladder emptying

Bowel Symptoms

  • Constipation - From fibroid pressure on rectum
  • Bloating and gas
  • Rectal pressure
  • Difficulty with bowel movements

Reproductive Symptoms

  • Infertility - Fibroids may interfere with implantation
  • Recurrent miscarriages
  • Complications during pregnancy
  • Preterm labor
  • Need for cesarean delivery

Systemic Symptoms

  • Iron deficiency anemia:
    • Fatigue and weakness
    • Shortness of breath
    • Dizziness
    • Headaches
    • Cold hands and feet
    • Brittle nails
  • Lower back pain
  • Leg pain (from nerve compression)

Red Flag Symptoms

Seek immediate medical attention for:

  • Severe, sudden pelvic pain
  • Heavy bleeding causing dizziness or fainting
  • Fever with pelvic pain
  • Rapidly growing abdomen
  • Postmenopausal bleeding

Causes

The exact cause of uterine fibroids remains unknown, but research has identified several factors that contribute to their development and growth. Fibroids appear to result from a complex interplay of genetic, hormonal, and environmental factors.

Hormonal Factors

Estrogen and Progesterone

  • Growth stimulation: Both hormones promote fibroid growth
  • Receptor expression: Fibroids have more hormone receptors than normal uterine muscle
  • Cyclic changes: Fibroids may grow and shrink with menstrual cycles
  • Pregnancy growth: Often enlarge during pregnancy when hormone levels are high
  • Menopausal shrinkage: Typically decrease after menopause

Other Hormonal Influences

  • Growth factors: IGF-1, EGF, TGF-β play roles
  • Prolactin: May contribute to fibroid growth
  • Insulin: Associated with metabolic factors

Genetic Factors

  • Chromosomal abnormalities: Found in 40-50% of fibroids
  • MED12 mutations: Present in 70% of fibroids
  • Familial clustering: 2.5x higher risk if first-degree relative affected
  • Racial predisposition: Genetic variants more common in Black women
  • Hereditary syndromes: Reed syndrome, hereditary leiomyomatosis

Cellular Origins

  • Stem cell theory: Arise from myometrial stem cells
  • Clonal expansion: Each fibroid grows from single mutated cell
  • Extracellular matrix: Excessive production creates bulk
  • Altered cell signaling: Disrupted apoptosis and proliferation

Environmental and Lifestyle Factors

Dietary Influences

  • Red meat consumption: Associated with increased risk
  • Green vegetables: May have protective effect
  • Vitamin D deficiency: Linked to fibroid development
  • Alcohol: May increase risk, especially beer
  • Caffeine: Conflicting evidence on association

Other Environmental Factors

  • Obesity: Increases estrogen production
  • Early menarche: Longer estrogen exposure
  • Stress: May influence hormonal balance
  • Environmental toxins: Endocrine disruptors possibly involved

Protective Factors

  • Pregnancy: Reduces risk, especially multiple pregnancies
  • Long-term contraceptive use: May decrease risk
  • Smoking: Paradoxically associated with lower risk (not recommended)
  • Exercise: Regular physical activity may be protective

Risk Factors

Understanding risk factors for uterine fibroids helps identify women who may be more likely to develop them and guides screening and prevention strategies.

Demographic Factors

  • Age:
    • Rare before age 20
    • Incidence increases through 30s and 40s
    • Peak prevalence in late 40s
    • New fibroids rare after menopause
  • Race/Ethnicity:
    • Black women: 2-3 times higher risk
    • Earlier onset in Black women (often by age 30)
    • More severe symptoms in Black women
    • Asian women: intermediate risk
    • White women: lowest risk
  • Family history:
    • First-degree relative: 2.5x increased risk
    • Multiple affected relatives: even higher risk
    • Early onset in families

Reproductive Factors

  • Nulliparity: Never having given birth increases risk
  • Early menarche: Before age 10-11
  • Late menopause: Prolonged estrogen exposure
  • Infertility: May be cause or effect
  • Time since last birth: Risk increases with years

Hormonal Factors

  • PCOS: Polycystic ovary syndrome
  • Hormone therapy: Certain formulations
  • Tamoxifen use: For breast cancer treatment
  • High estrogen states: Various causes

Lifestyle Factors

  • Obesity:
    • BMI >30 increases risk
    • Central adiposity particularly important
    • Increases estrogen production
  • Diet:
    • High red meat consumption
    • Low fruit and vegetable intake
    • Vitamin D deficiency
    • High glycemic index foods
  • Physical activity: Sedentary lifestyle increases risk
  • Stress: Chronic stress may contribute

Medical Conditions

  • Hypertension: Associated with fibroid development
  • Diabetes: May influence fibroid growth
  • Metabolic syndrome: Cluster of conditions
  • Thyroid disease: Some associations noted

Environmental Exposures

  • Endocrine disruptors: BPA, phthalates
  • Pesticides: Occupational or residential exposure
  • Hair relaxers: Chemical exposure concerns
  • Childhood abuse: Stress-related factors

Diagnosis

Diagnosing uterine fibroids typically begins with clinical symptoms and physical examination, followed by imaging studies to confirm the diagnosis, determine location and size, and plan treatment.

Clinical Evaluation

Medical History

  • Menstrual history and changes
  • Bleeding patterns and severity
  • Pain characteristics and timing
  • Urinary and bowel symptoms
  • Reproductive history and plans
  • Family history of fibroids
  • Previous treatments tried

Physical Examination

  • Abdominal examination:
    • Palpable mass if large fibroids
    • Abdominal distension
    • Tenderness assessment
  • Pelvic examination:
    • Enlarged, irregular uterus
    • Mobile vs fixed masses
    • Cervical evaluation
    • Adnexal assessment

Imaging Studies

Transvaginal Ultrasound (First-line)

  • High sensitivity for detecting fibroids
  • Determines size, number, and location
  • Evaluates endometrial thickness
  • Assesses ovaries
  • Doppler can evaluate blood flow
  • Cost-effective and widely available

Pelvic MRI

  • Most accurate for mapping fibroids
  • Best for surgical planning
  • Differentiates fibroids from adenomyosis
  • Evaluates fibroid degeneration
  • Assesses treatment eligibility
  • Higher cost than ultrasound

Sonohysterography

  • Saline infusion into uterus during ultrasound
  • Better visualization of submucosal fibroids
  • Evaluates endometrial cavity
  • Helps plan hysteroscopic procedures

Hysteroscopy

  • Direct visualization of uterine cavity
  • Confirms submucosal fibroids
  • Can remove small fibroids during procedure
  • Obtains tissue samples if needed

Laboratory Tests

  • Complete blood count: Check for anemia
  • Iron studies: Ferritin, iron, TIBC
  • Thyroid function: Rule out thyroid disorders
  • Pregnancy test: If reproductive age
  • Coagulation studies: If very heavy bleeding
  • Cancer markers: If concerning features

Differential Diagnosis

Conditions that may mimic fibroids:

  • Adenomyosis: Endometrial tissue in muscle wall
  • Endometrial polyps: Benign growths in lining
  • Ovarian masses: Can be confused on exam
  • Pregnancy: Early pregnancy or molar
  • Endometrial cancer: Especially postmenopausal
  • Leiomyosarcoma: Rare malignant tumor

Classification Systems

FIGO Classification (Submucosal)

  • Type 0: Pedunculated, entirely in cavity
  • Type 1: <50% intramural
  • Type 2: ≥50% intramural

Location Classification

  • Submucosal: Into uterine cavity
  • Intramural: Within muscle wall
  • Subserosal: Outer surface
  • Pedunculated: On a stalk
  • Cervical: In cervix (rare)

Treatment Options

Treatment for uterine fibroids is individualized based on symptom severity, fibroid size and location, age, desire for pregnancy, and proximity to menopause. Options range from watchful waiting to medical management to surgical interventions.

Expectant Management

For asymptomatic fibroids or mild symptoms:

  • Regular monitoring with ultrasound
  • Annual or biannual follow-up
  • Track symptom changes
  • Monitor for rapid growth
  • Consider intervention if symptoms worsen

Medical Management

Hormonal Treatments

  • GnRH agonists (Lupron, Synarel):
    • Temporarily shrink fibroids 30-60%
    • Induce medical menopause
    • Used pre-surgery or near menopause
    • Side effects: hot flashes, bone loss
    • Fibroids regrow when stopped
  • GnRH antagonists (Oriahnn, Myfembree):
    • Newer option with add-back hormones
    • Fewer side effects than agonists
    • Can use longer term
  • Progestins:
    • Mirena IUD for bleeding control
    • Depot medroxyprogesterone
    • May help some women
  • Birth control pills:
    • May regulate cycles
    • Reduce bleeding in some
    • Don't shrink fibroids

Non-Hormonal Medications

  • Tranexamic acid: Reduces heavy bleeding
  • NSAIDs: Pain relief, may reduce bleeding
  • Iron supplements: Treat anemia

Minimally Invasive Procedures

Uterine Artery Embolization (UAE)

  • Blocks blood flow to fibroids
  • 70-90% symptom improvement
  • Preserves uterus
  • Recovery 1-2 weeks
  • May affect fertility
  • Risk of fibroid expulsion

MRI-Guided Focused Ultrasound (MRgFUS)

  • Non-invasive thermal ablation
  • No incisions or anesthesia
  • Outpatient procedure
  • Limited by fibroid location/number
  • Long-term data still accumulating

Radiofrequency Ablation (Acessa)

  • Laparoscopic needle ablation
  • Destroys fibroid tissue
  • Preserves uterus
  • Multiple fibroids treatable

Surgical Options

Myomectomy (Fibroid Removal)

  • Hysteroscopic myomectomy:
    • For submucosal fibroids
    • Through vagina/cervix
    • Outpatient procedure
    • Quick recovery
  • Laparoscopic/Robotic myomectomy:
    • Small incisions
    • Shorter recovery than open
    • For smaller, fewer fibroids
  • Abdominal myomectomy:
    • Open surgery
    • For large/multiple fibroids
    • 6-8 week recovery
    • Future C-section may be needed

Hysterectomy

  • Definitive treatment - No recurrence
  • Approaches:
    • Vaginal (least invasive)
    • Laparoscopic/Robotic
    • Abdominal
  • Ovary decisions: Keep or remove
  • Recovery: 2-6 weeks depending on approach
  • Permanent: No future pregnancy

Emerging Treatments

  • Selective progesterone receptor modulators
  • Vitamin D supplementation studies
  • Green tea extract (EGCG)
  • Anti-fibrotic agents

Treatment Selection Factors

  • Symptom severity
  • Fibroid size, number, location
  • Age and proximity to menopause
  • Desire for future pregnancy
  • Previous treatments tried
  • Patient preferences
  • Surgical risks

Prevention

While uterine fibroids cannot be completely prevented due to genetic and hormonal factors beyond individual control, certain lifestyle modifications may help reduce risk or slow growth of existing fibroids.

Dietary Modifications

Foods to Increase

  • Green vegetables:
    • Cruciferous vegetables (broccoli, cabbage)
    • Leafy greens (spinach, kale)
    • May help metabolize estrogen
  • Fruits:
    • Citrus fruits high in vitamin C
    • Berries with antioxidants
    • Apples and pears
  • Whole grains: Help maintain healthy weight
  • Omega-3 fatty acids: Fish, flaxseed, walnuts
  • Green tea: Contains EGCG, may inhibit growth

Foods to Limit

  • Red meat: Associated with increased risk
  • High-fat dairy: May increase estrogen
  • Processed foods: High in sodium and additives
  • Refined sugars: Contribute to inflammation
  • Alcohol: Especially beer
  • Caffeine: Moderate consumption

Lifestyle Factors

Weight Management

  • Maintain healthy BMI
  • Reduce excess estrogen from fat tissue
  • Regular physical activity
  • Combination of cardio and strength training
  • At least 150 minutes weekly moderate exercise

Stress Reduction

  • Chronic stress may affect hormones
  • Meditation or mindfulness practices
  • Yoga or tai chi
  • Adequate sleep (7-9 hours)
  • Professional counseling if needed

Hormonal Considerations

  • Birth control choices:
    • Discuss options with provider
    • Some may help prevent growth
    • Consider non-hormonal methods
  • Pregnancy planning:
    • Pregnancy may be protective
    • Breastfeeding benefits
    • Spacing considerations

Environmental Factors

  • Reduce chemical exposure:
    • Choose organic when possible
    • Avoid BPA in plastics
    • Natural personal care products
    • Limit pesticide exposure
  • Vitamin D optimization:
    • Sun exposure (with protection)
    • Supplementation if deficient
    • Dietary sources

Early Detection

  • Regular gynecologic exams
  • Report menstrual changes
  • Track symptoms
  • Know family history
  • Baseline ultrasound if high risk

For Existing Fibroids

  • Monitor growth patterns
  • Maintain healthy lifestyle
  • Consider medical management early
  • Plan pregnancies if desired
  • Regular follow-up care

When to See a Doctor

Knowing when to seek medical care for fibroid symptoms is important for timely diagnosis and treatment. Some symptoms require immediate attention while others warrant scheduled evaluation.

Seek Emergency Care

  • Severe pelvic pain not relieved by medication
  • Heavy bleeding soaking >1 pad/hour for several hours
  • Dizziness, fainting, or palpitations with bleeding
  • Fever with pelvic pain (possible infection)
  • Sudden sharp pain (possible torsion)
  • Inability to urinate
  • Severe abdominal distension

Schedule Prompt Appointment

  • Periods lasting longer than 7 days
  • Heavy menstrual bleeding interfering with activities
  • Bleeding between periods
  • Pelvic pain or pressure
  • Frequent urination or difficulty emptying bladder
  • Constipation not relieved by dietary changes
  • Pain during intercourse
  • Rapidly enlarging abdomen

Routine Evaluation Needed

  • Family history of fibroids
  • Difficulty conceiving
  • Recurrent miscarriages
  • Feeling of fullness or bloating
  • Mild menstrual changes
  • Questions about treatment options

Regular Monitoring

  • Known fibroids require follow-up
  • Annual exams if asymptomatic
  • More frequent if symptoms present
  • Postmenopausal bleeding always needs evaluation
  • Rapid growth requires investigation

Information to Provide Your Doctor

  • Menstrual diary (flow, duration, symptoms)
  • Pain patterns and triggers
  • Urinary and bowel symptoms
  • Impact on daily activities
  • Previous treatments tried
  • Pregnancy plans
  • Family history details

Related Conditions

References

  1. Stewart EA, Cookson CL, Gandolfo RA, Schulze-Rath R. Epidemiology of uterine fibroids: a systematic review. BJOG. 2017;124(10):1501-1512.
  2. Giuliani E, As-Sanie S, Marsh EE. Epidemiology and management of uterine fibroids. Int J Gynaecol Obstet. 2020;149(1):3-9.
  3. American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 228: Management of Symptomatic Uterine Leiomyomas. Obstet Gynecol. 2021;137(6):e100-e115.
  4. Baird DD, Dunson DB, Hill MC, et al. High cumulative incidence of uterine leiomyoma in black and white women: ultrasound evidence. Am J Obstet Gynecol. 2003;188(1):100-107.
  5. De La Cruz MS, Buchanan EM. Uterine Fibroids: Diagnosis and Treatment. Am Fam Physician. 2017;95(2):100-107.
  6. Donnez J, Dolmans MM. Uterine fibroid management: from the present to the future. Hum Reprod Update. 2016;22(6):665-686.