In a 43‑year‑old woman with heavy vaginal bleeding who desires contraception, which investigation is mandatory before initiating any contraceptive therapy?

Mandatory Investigation Before Contraceptive Initiation in a 43-Year-Old Woman with Heavy Vaginal Bleeding

None of the listed tests (pelvic ultrasound, CT scan, or endometrial biopsy) are compulsory before prescribing most contraceptive methods, but given this patient's age (43 years) and heavy vaginal bleeding, endometrial biopsy is the most critical investigation to exclude endometrial hyperplasia or malignancy before initiating any treatment.

Understanding Contraceptive Requirements vs. Clinical Context

The 2024 CDC guidelines are explicit that no pelvic examination, imaging, or laboratory tests are mandatory (Class A) before initiating combined hormonal contraceptives or progestin-only methods 1, 2. The only Class A (essential and mandatory) examination for combined hormonal contraceptives is blood pressure measurement 2. For progestin-only pills, implants, and injectables, no examinations or tests are required at all 2.

However, this guideline framework applies to "patients who are presumed to be healthy" 1. Your patient is NOT presumed healthy—she presents with heavy vaginal bleeding, which is a symptom requiring evaluation before treatment, not a contraceptive eligibility issue 3, 4.

Why Endometrial Biopsy Takes Priority

Age and Cancer Risk

Women over 45 years with abnormal uterine bleeding require endometrial biopsy to exclude endometrial hyperplasia or malignancy 4. While your patient is 43 years old, the American College of Radiology and clinical guidelines recommend endometrial sampling for women 35 years or older with recurrent anovulation or risk factors for endometrial cancer 5. At 43 years, she is in the perimenopausal transition when endometrial pathology becomes increasingly prevalent 4, 5.

Bleeding as a Red Flag

Heavy vaginal bleeding itself mandates ruling out structural lesions and endometrial pathology before initiating hormonal treatment 3, 4. The ACOG recommends "first ruling out underlying pathology, such as pregnancy, infection, and structural lesions, before initiating treatment for prolonged menstrual bleeding" 3. Endometrial biopsy is essential to exclude endometrial hyperplasia or malignancy, particularly given the age and prolonged bleeding pattern 4.

Pelvic Ultrasound: Important but Not Sufficient Alone

Pelvic ultrasound (transvaginal preferred) should be performed to evaluate for structural abnormalities including fibroids, polyps, adenomyosis, and endometrial thickness 4. Half of women consulting for heavy bleeding have uterine abnormalities, most commonly fibroids (under 40 years) and endometrial polyps (over 40 years) 6.

However, ultrasound alone is insufficient for diagnosing endometrial hyperplasia or carcinoma—it must be combined with endometrial biopsy 4, 7. While ultrasound can measure endometrial thickness and help triage patients, tissue diagnosis remains essential in this age group with abnormal bleeding 7, 8.

CT Scan: Not Indicated

CT scan has no role in the routine evaluation of abnormal uterine bleeding and is not mentioned in any guideline for this indication 4. It exposes the patient to unnecessary radiation and does not provide adequate endometrial assessment.

Practical Clinical Algorithm

Step 1: Immediate Mandatory Tests

• Pregnancy test (β-hCG) to rule out pregnancy complications 4
• Blood pressure measurement if combined hormonal contraceptives are being considered 2
• Complete blood count to assess for anemia 9

Step 2: Essential Diagnostic Workup (Before Treatment)

• Endometrial biopsy to exclude hyperplasia or malignancy 4, 5
• Transvaginal ultrasound to evaluate structural abnormalities and endometrial thickness 4, 6
• STI screening if risk factors present 3, 4

Step 3: Treatment Initiation

Once pathology is excluded, combined oral contraceptives containing 30-35 μg ethinyl estradiol are first-line treatment for heavy menstrual bleeding 3. Alternatively, the levonorgestrel IUD reduces menstrual blood loss by 86-97% and is highly effective for women over 45 3, 4.

Critical Pitfall to Avoid

Do not start hormonal contraception for "contraceptive purposes" while ignoring the underlying symptom of heavy bleeding 3, 4. The bleeding itself requires evaluation regardless of contraceptive needs. Treating the symptom without excluding serious pathology (especially endometrial cancer in this age group) represents a dangerous missed diagnosis 4, 5.

Answer to the Question

Of the three options provided, endometrial biopsy (C) is the most compulsory investigation before advising treatment in this specific clinical scenario 4, 5. While technically not required for contraceptive eligibility, it is mandatory for safe management of her presenting complaint—heavy vaginal bleeding at age 43 3, 4.