Pelvic Pain: A Comprehensive MCCQE1 Guide

Introduction

Pelvic pain is a frequent presentation in Canadian emergency departments and family practice clinics. For the MCCQE1, candidates must demonstrate a structured approach to differentiating between acute life-threatening conditions (e.g., ectopic pregnancy, ovarian torsion) and chronic pathologies (e.g., endometriosis).

Understanding the CanMEDS roles is crucial here, particularly Medical Expert (diagnostic reasoning) and Communicator (taking a sensitive sexual history).

Clinical Approach to Acute Pelvic Pain

The immediate goal in the acute setting is to rule out surgical emergencies and pregnancy-related complications.

Initial Assessment (The “Safety First” Approach)

History Taking Strategy

Differential Diagnosis

The differential for pelvic pain is broad. Use the Anatomical Approach to organize your thoughts for the MCCQE1.

High-Yield Conditions for MCCQE1

1. Ectopic Pregnancy

The implantation of a fertilized ovum outside the endometrial cavity (98% tubal).

• Risk Factors: Previous ectopic, PID, Tubal surgery, IUD use (if pregnancy occurs), Smoking, IVF.
• Diagnosis:
  • Positive β-hCG (usually lower than expected for dates).
  • Transvaginal Ultrasound (TVUS): Empty uterus with adnexal mass or “ring of fire”.
• Management (Canadian Guidelines):
  • Unstable: ABCs, Laparoscopy (Salpingectomy).
  • Stable: Methotrexate (MTX) if criteria met (mass <3.5-4 cm, no fetal heart rate, β-hCG <5000 IU/L, compliant patient).

2. Pelvic Inflammatory Disease (PID)

Polymicrobial infection of the upper genital tract (Chlamydia, Gonorrhea, Anaerobes).

• Minimum Clinical Criteria for Treatment: Pelvic/lower abdominal pain AND one of:
  • Cervical Motion Tenderness (CMT)
  • Uterine tenderness
  • Adnexal tenderness
• MCCQE1 Tip: Have a low threshold for treatment to prevent sequelae (Infertility, Ectopic, Chronic Pelvic Pain).
• Treatment (Outpatient): Ceftriaxone IM (single dose) + Doxycycline PO (14 days) + Metronidazole PO (14 days).

3. Ovarian Torsion

• Pathophysiology: Rotation of the ovary occluding ovarian vessels $\rightarrow$ ischemia.
• Presentation: Sudden onset, severe unilateral pain, Nausea/Vomiting (very common).
• Diagnosis: Doppler Ultrasound (decreased or absent flow). Note: Normal flow does not rule out torsion (venous vs arterial flow).
• Management: Laparoscopic detorsion (Emergency).

Diagnostic Investigations

Laboratory

• Urine Pregnancy Test (β-hCG): The “Vital Sign” of gynecology.
• CBC: Leukocytosis (Infection), Anemia (Blood loss).
• Urinalysis/Culture: UTI, Hematuria (Stones).
• Vaginal Swabs (NAAT): Chlamydia trachomatis, Neisseria gonorrhoeae.
• Vaginal Wet Mount: Bacterial vaginosis, Trichomonas, Yeast.

Imaging

• Transvaginal Ultrasound (TVUS): The gold standard first-line imaging modality in Canada for female pelvic pain.
• CT Abdomen/Pelvis: Better for GI pathology (Appendicitis, Diverticulitis) or if US is equivocal.
• MRI: Second-line for complex adnexal masses or deep infiltrating endometriosis.

Canadian Guidelines (SOGC) Highlights

Specific guidelines from the Society of Obstetricians and Gynaecologists of Canada (SOGC) relevant to MCCQE1:

1. Endometriosis:

   • Clinical diagnosis is accepted; laparoscopy is no longer mandatory to start medical therapy.
   • First-line: NSAIDs + Continuous Combined Hormonal Contraceptives (CHC) or Progestins (Dienogest).

2. Chronic Pelvic Pain:

   • Adopt a multidisciplinary approach (Physiotherapy, Psychology, Pain specialists).
   • Avoid long-term opioids.

3. Ruptured Ovarian Cysts:

   • Most uncomplicated hemorrhagic cysts are managed conservatively with analgesia.
   • Follow-up ultrasound in 6-12 weeks to ensure resolution.

Key Points to Remember for MCCQE1

Use this checklist for your final review:

• Always rule out pregnancy in a reproductive-age female with abdominal pain.
• Rh Status: Check blood type and screen; give WinRho if Rh-negative and bleeding.
• PID Treatment: Treat partners! (Contact tracing is a Public Health requirement).
• Ultrasound: Is the modality of choice. Do not order a CT first for suspected gyn pathology unless torsion/appendicitis is equally likely and US is unavailable.
• Consent: For exams involving sensitive areas, ensure proper chaperoning and informed consent (CanMEDS Professional).

Common Abbreviations

LMP   : Last Menstrual Period
PID   : Pelvic Inflammatory Disease
TVUS  : Transvaginal Ultrasound
bHCG  : Beta-Human Chorionic Gonadotropin
STI   : Sexually Transmitted Infection
TOA   : Tubo-ovarian Abscess
CMT   : Cervical Motion Tenderness

Sample Question

Clinical Scenario

A 24-year-old nulliparous woman presents to the Emergency Department with a 2-hour history of sudden onset, severe left lower quadrant pain. She reports two episodes of vomiting since the pain started. Her last menstrual period was 8 weeks ago, but she notes she has irregular cycles. She is sexually active and uses condoms intermittently.

Vitals:

• Temp: 37.1°C
• HR: 104 bpm
• BP: 110/70 mmHg
• RR: 18/min

Physical Exam:

• Abdomen: Soft, tender in LLQ with voluntary guarding. No rebound.
• Pelvic: Normal external genitalia. Left adnexal tenderness and fullness palpated. Cervical motion tenderness is present.

Investigations:

• Urine β-hCG: Negative

Question

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

• A. Administer IM Ceftriaxone and oral Doxycycline
• B. Urgent CT of the Abdomen and Pelvis
• C. Urgent Transvaginal Doppler Ultrasound
• D. Reassurance and discharge with NSAIDs
• E. Serum quantitative β-hCG

Explanation

The correct answer is:

• C. Urgent Transvaginal Doppler Ultrasound

Detailed Analysis

• Diagnosis: The clinical picture is highly suggestive of Ovarian Torsion. The key features are the sudden onset of severe pain, nausea/vomiting (very specific for torsion due to vagal stimulation), and a tender adnexal mass.
• Why C is correct: In a patient with a negative pregnancy test (ruling out ectopic) and clinical signs of torsion, the immediate diagnostic step is a Doppler Ultrasound to assess ovarian blood flow. Torsion is a surgical emergency; time is ovary.
• Why A is incorrect: This is the treatment for PID. While she has CMT and adnexal tenderness, the sudden onset and vomiting are more characteristic of torsion. PID usually presents with gradual onset, fever, and bilateral pain.
• Why B is incorrect: Ultrasound is the first-line modality for gynecologic pathology in Canada. CT involves radiation and is less sensitive for ovarian blood flow compared to Doppler US.
• Why D is incorrect: This patient has tachycardia and severe pain requiring investigation. Discharging without ruling out torsion is negligent.
• Why E is incorrect: The urine β-hCG is already negative. While a serum test is more sensitive, a negative urine test at 8 weeks of amenorrhea generally excludes pregnancy/ectopic with high reliability. Waiting for a serum quantitative result delays the critical imaging for torsion.

References

1. Society of Obstetricians and Gynaecologists of Canada (SOGC). (2023). Clinical Practice Guidelines: Management of Acute Pelvic Pain. Link to SOGC 
2. Medical Council of Canada. (2023). MCCQE Part I Objectives: Abdominal Pain / Pelvic Pain.
3. Public Health Agency of Canada. Canadian Guidelines on Sexually Transmitted Infections.
4. Toronto Notes 2024. Gynecology Chapter: Acute Pelvic Pain.