Vaginal Bleeding: Excessive, Irregular, Abnormal

Introduction

Abnormal Uterine Bleeding (AUB) is a common clinical presentation in Canadian primary care and gynecology, accounting for a significant portion of referrals. For MCCQE1 preparation, understanding the etiology, appropriate investigation, and management of AUB according to the Society of Obstetricians and Gynaecologists of Canada (SOGC) guidelines is essential.

AUB is defined as bleeding from the uterine corpus that is abnormal in duration, volume, frequency, or regularity. It encompasses terms previously known as menorrhagia and metrorrhagia, though current terminology favors the FIGO classification system (PALM-COEIN).

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Canadian Context: In Canada, AUB is a leading cause of hysterectomy. The CanMEDS Medical Expert role requires you to balance conservative medical management with surgical interventions, while the Health Advocate role emphasizes screening for endometrial cancer in high-risk populations.

Etiology: The PALM-COEIN Classification

The International Federation of Gynecology and Obstetrics (FIGO) system classifies causes of AUB into structural (PALM) and non-structural (COEIN) etiologies. This is a high-yield concept for the MCCQE1.

Structural (PALM)

Structural Causes

These entities can be visualized via imaging (Ultrasound/Hysteroscopy) or histopathology.

P - Polyp: AUB-P. Endometrial or endocervical. usually benign.
A - Adenomyosis: AUB-A. Endometrial tissue within the myometrium. Associated with dysmenorrhea and a bulky, tender uterus.
L - Leiomyoma (Fibroids): AUB-L. Benign smooth muscle tumors. Subclassified as submucosal (most likely to cause bleeding) or other.
M - Malignancy & Hyperplasia: AUB-M. Endometrial hyperplasia or carcinoma. Critical to rule out in women <40 years old.

Clinical Evaluation

The goal of the evaluation is to determine the acuity (hemodynamic stability), etiology, and impact on quality of life.

1. History

Focus on the “ABCDE” of bleeding and risk factors.

Pattern: Frequency, duration, regularity, volume (clots >2.5 cm, changing protection <2 hours).
Associated Symptoms: Pain (dysmenorrhea), discharge, fever, systemic signs of bleeding (fatigue, syncope).
Medical History: Coagulopathies, thyroid disease, medications (warfarin, DOACs, herbal supplements).
Obstetric/Sexual History: ALWAYS rule out pregnancy.

🚩 MCCQE1 Red Flags for Endometrial Cancer

Age > 40 years
Obesity (BMI > 30) - Peripheral conversion of androgens to estrogen
Nulliparity
Lynch Syndrome (HNPCC)
Unopposed Estrogen exposure (PCOS, estrogen-only HRT)
Tamoxifen use
Diabetes Mellitus

2. Physical Examination

Vitals: Assess for hemodynamic instability (tachycardia, hypotension).
General: Signs of anemia (pallor), thyroid disease, PCOS (hirsutism, acne), bleeding disorders (petechiae, bruising).
Abdominal: Masses, tenderness.
Pelvic (Bimanual & Speculum):
- Assess source of bleeding (vulva, vagina, cervix, uterus).
- Uterine size, contour (fibroids), mobility, tenderness (PID, adenomyosis).
- Cervical lesions (polyps, cancer).

3. Investigations

Step 1: Laboratory Studies

Beta-hCG: Mandatory for all women of reproductive age.
CBC: Evaluate hemoglobin and platelets.
Ferritin: Assess iron stores (often low in chronic AUB).
TSH: If symptoms of thyroid dysfunction or AUB-O.
Coagulation Profile (PT/PTT): If history suggests coagulopathy (e.g., heavy bleeding since menarche).
Pap Test: Follow provincial screening guidelines (cervical pathology).

Step 2: Diagnostic Imaging

Transvaginal Ultrasound (TVUS): First-line imaging modality in Canada for structural causes (Fibroids, Polyps, Endometrial thickness).
Sonohysterography (Saline Infusion): Superior for intracavitary lesions (polyps, submucosal fibroids).

Step 3: Tissue Sampling (Endometrial Biopsy)

This is a critical decision point in MCCQE1 scenarios. According to SOGC Guidelines, perform Endometrial Biopsy (EMB) if:

Age > 40 years.
Age < 40 years with risk factors for endometrial cancer (obesity, PCOS, unopposed estrogen, failure of medical management).
Postmenopausal bleeding (ANY amount).

Canadian Guidelines for Management (SOGC)

Management depends on etiology (PALM-COEIN), fertility desires, and severity.

Medical Management

First-line therapy is usually medical unless there are significant structural lesions or suspected malignancy.

Class	Options	Mechanism	Clinical Notes (MCCQE1)
Non-Hormonal	Tranexamic Acid	Antifibrinolytic	Taken only during menses. Reduces bleeding by up to 50%. Contraindicated in active thromboembolic disease.
	NSAIDs (Naproxen, Ibuprofen)	Prostaglandin synthetase inhibitor	Reduces bleeding and dysmenorrhea.
Hormonal	LNG-IUS (Mirena)	Progestin release	First-line hormonal option for heavy menstrual bleeding. Reduces blood loss by >90%.
	Combined Hormonal Contraceptives (CHC)	OCP, Patch, Ring	Regulates cycle, thins endometrium. Good for AUB-O and AUB-E.
	Oral Progestins	Cyclic or Continuous	Cyclic (e.g., Medroxyprogesterone) induces withdrawal bleed; Continuous induces amenorrhea.
	GnRH Agonists	Leuprolide	Induces “medical menopause.” Short-term use (e.g., pre-operative to shrink fibroids).

Surgical Management

Reserved for failure of medical management, contraindications to medications, or significant structural pathology.

Endometrial Ablation: Minimally invasive. Contraindicated if the patient desires future fertility or has endometrial hyperplasia/cancer.
Myomectomy: Removal of fibroids (preserves uterus/fertility).
Hysterectomy: Definitive treatment.

Specific Clinical Scenarios

Acute Severe Bleeding (Hemodynamically Unstable)

Stabilize: ABCs, large-bore IVs, fluids, cross-match blood.
High-dose IV Estrogen: (e.g., Premarin) stabilizes endometrial lining.
Tranexamic Acid: IV or PO.
Surgical: D&C or uterine artery embolization if medical therapy fails.

Adolescents

Most common cause is Anovulation (immature HPO axis).
Second most common: Coagulopathy (e.g., von Willebrand Disease).
Management: Usually medical (OCPs, Tranexamic acid). Avoid D&C.

Postmenopausal Bleeding

Definition: Bleeding occurring >1 year after menopause.
Rule: Cancer until proven otherwise.
Investigation: TVUS (Endometrial thickness <4mm or <5mm depending on local protocol makes cancer unlikely) AND/OR Endometrial Biopsy.

Key Points to Remember for MCCQE1

High-Yield Takeaways

Pregnancy Test: The first test in any woman of reproductive age with AUB is a Beta-hCG.
Biopsy Criteria: Memorize the SOGC criteria for endometrial biopsy (Age >40 OR risk factors).
First-Line Treatment: Know that the Levonorgestrel-releasing Intrauterine System (LNG-IUS) is highly effective and often first-line for heavy menstrual bleeding.
Terminology: Use PALM-COEIN terminology; avoid “dysfunctional uterine bleeding.”
Postmenopausal Bleeding: Any bleeding after menopause requires investigation for endometrial cancer.

Sample Question

Clinical Scenario

A 46-year-old female presents to your family medicine clinic with a 6-month history of increasingly heavy and irregular menstrual bleeding. She reports passing clots “the size of golf balls” and feeling fatigued. Her past medical history is significant for obesity (BMI 34), type 2 diabetes, and hypertension. She is G0P0. She is not sexually active currently. Physical examination reveals a normal-appearing cervix and a slightly enlarged, mobile, non-tender uterus.

Question

Which one of the following is the most appropriate next step in the investigation of this patient?

A. Reassurance and trial of combined oral contraceptive pills
B. Transvaginal ultrasound only
C. Endometrial biopsy
D. Serum FSH and LH levels
E. Referral for hysterectomy

Explanation

The correct answer is:

C. Endometrial biopsy

Detailed Explanation:

This patient presents with Abnormal Uterine Bleeding (AUB) and possesses multiple risk factors for endometrial hyperplasia and carcinoma.

Canadian Guidelines (SOGC): The guidelines clearly state that an endometrial biopsy is indicated in women with AUB who are > 40 years of age.
Risk Factors: Even if she were younger, she has significant risk factors: Obesity (peripheral conversion of androgens to estrogens), Diabetes, and Nulliparity (unopposed estrogen exposure).
Why not others?
- A (OCPs): While OCPs treat AUB, you cannot start treatment without ruling out malignancy in a high-risk patient. Masking the symptoms could delay a cancer diagnosis.
- B (Ultrasound): While an ultrasound is part of the workup (to look for structural causes like fibroids), it does not provide a histological diagnosis. In a 46-year-old with these risk factors, tissue diagnosis (biopsy) is mandatory regardless of ultrasound findings.
- D (FSH/LH): These are used to diagnose menopause or POI, not to evaluate AUB or rule out cancer.
- E (Hysterectomy): This is a definitive treatment, not a diagnostic step. It is overly aggressive without a confirmed diagnosis.

CanMEDS Role - Medical Expert: Recognizing the “Red Flags” for malignancy and ordering the appropriate diagnostic test (Biopsy) before initiating treatment.

References

Society of Obstetricians and Gynaecologists of Canada (SOGC). (2013). Abnormal Uterine Bleeding in Pre-Menopausal Women. Clinical Practice Guideline No. 292.
Society of Obstetricians and Gynaecologists of Canada (SOGC). (2018). Guideline No. 359: Management of Uterine Fibroids.
Munro, M. G., et al. (2011). FIGO classification system (PALM-COEIN) for causes of abnormal uterine bleeding in nongravid women of reproductive age. International Journal of Gynecology & Obstetrics.
Medical Council of Canada. (2023). MCCQE Part I Clinical Decision-Making and Multiple-Choice Questions Objectives.
Toronto Notes. (2023). Gynecology: Abnormal Uterine Bleeding.