7.4 Abnormal Uterine Bleeding, Gynecologic Infections, & Contraception/Menopause

Abnormal Uterine Bleeding, Gynecologic Infections, Contraception, & Menopause

This section covers key gynecologic topics essential for MCCQE Part I, including abnormal uterine bleeding frameworks, vaginitis, pelvic inflammatory disease, contraceptive eligibility, and menopausal hormone therapy under SOGC guidelines.

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Abnormal Uterine Bleeding (AUB) & PALM-COEIN Classification

Abnormal Uterine Bleeding (AUB) refers to bleeding from the uterine corpus that is abnormal in duration, frequency, regularity, or volume in non-pregnant reproductive-aged women.

FIGO PALM-COEIN System

Structural Etiologies (PALM - Diagnosed by Imaging/Histology):
  P - Polyp (Endometrial or Cervical)
  A - Adenomyosis (Endometrial tissue within myometrium; enlarged globular tender uterus)
  L - Leiomyoma (Submucosal, Intramural, Subserosal fibroids)
  M - Malignancy & Hyperplasia (Endometrial intraepithelial neoplasia, carcinoma)

Non-Structural Etiologies (COEIN):
  C - Coagulopathy (von Willebrand disease, heavy menses since menarche)
  O - Ovulatory dysfunction (PCOS, hypothyroidism, hyperprolactinemia, perimenopause)
  E - Endometrial (Primary endometrial vascular repair dysfunction)
  I - Iatrogenic (Exogenous hormones, IUDs, anticoagulants)
  N - Not otherwise classified

Diagnostic Workup of AUB

1. Exclude Pregnancy: Beta-hCG urine/serum test is the mandatory first step in any reproductive-aged woman presenting with AUB.
2. Laboratory Testing: CBC, ferritin, TSH, prolactin, coagulation testing (if heavy menses since menarche).
3. Pelvic Ultrasound: Transvaginal Ultrasound (TVUS) to assess structural lesions (fibroids, polyps, adenomyosis) and endometrial thickness.
4. Endometrial Biopsy (Pipelle) Indications:
   • Any woman aged ≥40 years presenting with AUB.
   • Women aged <40 years with risk factors for endometrial carcinoma (obesity, PCOS, long-standing unopposed estrogen, Lynch syndrome).
   • Any postmenopausal woman with bleeding and TVUS endometrial thickness >4 mm.

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Gynecologic & Pelvic Infections

Differential Diagnosis of Vaginitis

Pelvic Inflammatory Disease (PID)

PID is an ascending polymicrobial infection of the upper female genital tract (Neisseria gonorrhoeae, Chlamydia trachomatis, vaginal anaerobes).

• Clinical Diagnosis (SOGC Criteria): Empiric treatment should be initiated in sexually active young women experiencing pelvic/lower abdominal pain if one or more of the following minimum clinical criteria are present on pelvic exam:
  1. Cervical motion tenderness ("Chandelier sign")
  2. Uterine tenderness
  3. Adnexal tenderness
• Outpatient Regimen: Ceftriaxone 500 mg IM single dose + Doxycycline 100 mg PO BID × 14 days + Metronidazole 500 mg PO BID × 14 days.
• Inpatient Regimen Indications (SOGC): Pregnancy, tubo-ovarian abscess (TOA), severe illness/high fever, surgical emergencies cannot be ruled out, or failure/intolerance of oral outpatient therapy. Regimen: IV Cefotetan 2 g q12h + IV Doxycycline 100 mg q12h OR IV Clindamycin 900 mg q8h + IV Gentamicin.

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Contraception & WHO Medical Eligibility Criteria (MEC)

SOGC endorses the WHO Medical Eligibility Criteria for contraceptive use.

Absolute Contraindications to Combined Hormonal Contraceptives (CHC: Pill, Patch, Ring)

Combined estrogen-progestin contraceptives carry thrombosis and vascular risks. They are MEC Category 4 (Unacceptable health risk) in:

1. Age ≥35 years AND smoking ≥15 cigarettes/day.
2. Severe hypertension (SBP ≥160 or DBP ≥100 mmHg) or vascular disease.
3. Current or past history of venous thromboembolism (VTE/PE), known thrombophilia, or major surgery with prolonged immobilization.
4. Migraine with aura (focal neurological symptoms) at any age (significantly increases ischemic stroke risk).
5. History of ischemic heart disease, stroke, or complicated valvular heart disease.
6. Active breast cancer.
7. Severe cirrhosis, hepatocellular adenoma, or malignant liver tumors.
8. Diabetes mellitus with microvascular complications (retinopathy, nephropathy, neuropathy) or duration >20 years.

Long-Acting Reversible Contraception (LARC)

• Levonorgestrel IUD (LNG-IUD / Mirena): Highly effective (>99%). First-line medical treatment for AUB-L and AUB-A (reduces menstrual blood loss by >90%).
• Copper IUD (Cu-IUD): Non-hormonal option lasting 5–10 years. Also serves as the most effective emergency contraceptive when inserted within 5 days (120 hours) of unprotected intercourse.

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Menopause & Menopausal Hormone Therapy (MHT)

Menopause is defined clinically as 12 consecutive months of amenorrhea without underlying pathology (average age in Canada: 51.5 years). Premature Ovarian Insufficiency (POI) is menopause occurring before age 40.

Indications for Menopausal Hormone Therapy (MHT)

SOGC guidelines state MHT is indicated for:

1. Moderate-to-severe vasomotor symptoms (hot flashes, night sweats).
2. Prevention of osteoporosis in symptomatic women <60 years old or within 10 years of menopause.
3. Genitourinary Syndrome of Menopause (GSM / vulvovaginal atrophy): Local low-dose vaginal estrogen is first-line.

SOGC Prescribing Rules for Systemic MHT

• Intact Uterus: Systemic Estrogen + Progestin (or Bazedoxifene) MUST be prescribed. Unopposed systemic estrogen in a woman with a uterus causes endometrial hyperplasia and markedly increases endometrial adenocarcinoma risk.
• Prior Hysterectomy: Estrogen-ONLY therapy is prescribed (progestin is unnecessary).

Contraindications to Systemic MHT

Unexplained vaginal bleeding, active VTE/PE, recent arterial thromboembolic event (MI/stroke), active liver disease, history of breast cancer, or known estrogen-dependent neoplasia.

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SOGC Clinical Practice Pearls & Exam Traps

⚠️ EXAM TRAP: Any postmenopausal bleeding is endometrial cancer until proven otherwise! Transvaginal ultrasound demonstrating endometrial thickness >4 mm requires immediate endometrial biopsy (Pipelle).

🩺 CLINICAL SCENARIO: A 38-year-old woman who smokes 20 cigarettes per day requests oral contraceptive pills for heavy menses. What is the most appropriate management based on SOGC guidelines?

• CHCs are strictly contraindicated (Category 4) due to catastrophic VTE/stroke risk.
• Counsel the patient on a Levonorgestrel IUD (LNG-IUD), which provides superior contraception, treats her heavy menses, and avoids estrogenic thrombotic risk.