14.1 Abnormal Uterine Bleeding & Uterine Fibroids

14.1 Abnormal Uterine Bleeding & Uterine Fibroids

Abnormal Uterine Bleeding (AUB) is one of the most common presenting complaints in gynaecological practice, accounting for over 30% of outpatient consultations in women of reproductive age. A thorough understanding of its classification, underlying structural abnormalities—specifically uterine leiomyomas—and evidence-based management protocols is essential for the UPSC Combined Medical Services (CMS) examination.

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PALM-COEIN Classification System (FIGO 2011/2018)

To standardize terminology and clinical evaluation, the International Federation of Gynecology and Obstetrics (FIGO) established the PALM-COEIN classification system. This system divides AUB in non-pregnant women of reproductive age into nine discrete categories, stratified into structural causes (visualized via imaging or histopathology) and non-structural causes.

Clinical Pearl for UPSC CMS: Heavy Menstrual Bleeding (HMB) is defined objectively as menstrual blood loss >80 mL per cycle or bleeding lasting >7 days. Subjectively, it is any excessive menstrual blood loss that interferes with a woman's physical, emotional, social, and material quality of life.

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Uterine Leiomyomas (Fibroids)

Uterine leiomyomas are benign, monoclonal, estrogen- and progesterone-dependent smooth muscle tumors originating from myometrial smooth muscle cells and surrounding extracellular matrix. They occur in up to 70–80% of women by age 50 and represent the single most common indication for hysterectomy worldwide.

Risk & Protective Factors

• Risk Factors: Nulliparity, early menarche (<10 years), obesity (increased peripheral aromatization of androgens to estrogens in adipose tissue), African ethnicity, positive family history (first-degree relative), and polycystic ovary syndrome.
• Protective Factors: Multiparity, increased duration of lactation, combined oral contraceptive pill use, and smoking (induces hepatic hypoestrogenism via cytochrome P450 activation).

FIGO Subclassification System for Leiomyomas (Types 0 to 8)

FIGO categorizes leiomyomas based on their exact anatomical relation to the endometrium and serosa:

FIGO Classification Table:
Type 0: Pedunculated intracavitary submucosal
Type 1: Submucosal, <50% intramural
Type 2: Submucosal, ≥50% intramural
Type 3: 100% Intramural, contacts endometrium
Type 4: 100% Intramural, no contact with endometrium/serosa
Type 5: Subserosal, ≥50% intramural
Type 6: Subserosal, <50% intramural
Type 7: Pedunculated subserosal
Type 8: Other (cervical, broad ligament, parasitic)
Hbrid: Two numbers (e.g., 2-5) indicating submucosal and subserosal extent

Secondary Degenerations of Fibroids

As fibroids outgrow their blood supply (derived primarily from peripheral arcade vessels), secondary degenerative changes occur:

1. Hyaline Degeneration (60–65%): The most common degeneration; smooth muscle tissue is replaced by homogeneous pink, acellular hyaline tissue.
2. Cystic Degeneration (4%): Hyaline tissue liquefies to form fluid-filled cystic cavities; frequently follows hyaline degeneration.
3. Calcific / Calcareous Degeneration (10%): Deposition of calcium carbonate and phosphate, typically in postmenopausal women secondary to circulatory failure; visible as a 'womb stone' on pelvic X-ray.
4. Red (Carneous) Degeneration: Aseptic necrobiosis occurring characteristically during the second trimester of pregnancy or early puerperium. Rapid estrogen-driven enlargement outstrips blood supply, causing venous thrombosis and hemorrhagic infarction. Presenting features include acute focal abdominal pain, localized uterine tenderness over the fibroid, low-grade fever, leukocytosis, and elevated ESR. Management is strictly conservative with bed rest, hydration, and analgesics (Paracetamol / short-course NSAIDs before 32 weeks).
5. Myxoid Degeneration: Soft gelatinous material within the tumor.
6. Malignant Transformation (Leiomyosarcoma): Occurs in <0.1% of fibroids; suspected when a rapid growth occurs in postmenopausal women.

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Diagnostic Workup

1. Bimanual Pelvic Examination: Reveals an enlarged, firm, irregularly contoured, non-tender, mobile uterus (unless fixed by adhesions or broad ligament fibroids).
2. Transvaginal Ultrasonography (TVS): First-line imaging modality. Demonstrates well-defined, hypoechoic, heterogeneous myometrial masses with acoustic shadowing.
3. Saline Infusion Sonohysterography (SIS) / Hysteroscopy: Gold standard for evaluating submucosal cavity distortion (Types 0, 1, and 2).
4. Magnetic Resonance Imaging (MRI): Most precise imaging modality for mapping exact fibroid count, size, and FIGO location prior to planned myomectomy or Uterine Artery Embolization.

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Evidence-Based Management Protocols

1. Medical Management

Indicated for symptom control in mild-to-moderate AUB-L, preoperatively to shrink fibroids and correct anemia, or in women nearing menopause.

• Tranexamic Acid: Antifibrinolytic that competitively inhibits plasminogen activation. Administered at 1 g orally TID during active menses; reduces menstrual blood loss by 40–50% without altering fibroid volume.
• NSAIDs (Mefenamic acid 500 mg TID): Inhibits cyclooxygenase, reducing endometrial prostaglandin (PGE2/PGF2α) synthesis. Reduces blood loss by 20–30% and alleviates dysmenorrhea.
• Levonorgestrel Intrauterine System (LNG-IUS / Mirena 52 mg): Releases 20 mcg LNG daily directly into the endometrial cavity. Induces profound endometrial atrophy. Gold standard medical management for AUB-L when no cavity distortion (FIGO Types 3–8) is present, reducing blood loss by >90% at 12 months.
• GnRH Agonists (Leuprolide acetate 3.75 mg monthly IM / Goserelin 3.6 mg SC): Binds to pituitary GnRH receptors, causing initial flare followed by receptor downregulation and profound hypoestrogenism. Reduces fibroid volume by 40–60% within 3 months and induces amenorrhea. Limited to 3–6 months preoperatively due to bone mineral density (BMD) loss and vasomotor symptoms (unless add-back hormone therapy is co-administered).
• Selective Progesterone Receptor Modulators (SPRMs - Ulipristal Acetate 5 mg daily): Inhibits progesterone-driven fibroid cell proliferation and induces apoptosis without severe hypoestrogenism. Used as short-term preoperative therapy.

2. Surgical & Interventional Management

• Uterine Artery Embolization (UAE / UFE): Interventional radiologic procedure where polyvinyl alcohol (PVA) microspheres are injected into bilateral uterine arteries via femoral artery access. Leads to ischemic necrosis and infarction of fibroids with ~50% volume reduction. Absolute Contraindication: Active pelvic infection, pregnancy, suspected malignancy, and women desiring future fertility (due to risk of ovarian failure and impaired placentation).
• Myomectomy: Surgical excision of fibroids preserving the uterus. Indicated for women desiring future childbearing or organ preservation.
  • Hysteroscopic Myomectomy: Choice for FIGO Type 0 and Type 1 submucosal fibroids <4 cm.
  • Laparoscopic / Abdominal Myomectomy: Indicated for intramural (Types 3, 4) and subserosal (Types 5, 6, 7) fibroids. Note: Enteric opening of the endometrial cavity during myomectomy mandates planned elective Cesarean section at term in subsequent pregnancies to prevent uterine rupture.
• Hysterectomy: Total or subtotal abdominal, laparoscopic, or vaginal hysterectomy. The definitive cure for AUB-L in women who have completed childbearing.