What is the recommended initial work‑up, including imaging, for a woman presenting with menorrhagia?

Recommended Initial Work-Up for Menorrhagia

Combined transabdominal and transvaginal ultrasound with Doppler is the first-line imaging study for evaluating menorrhagia, serving as the primary modality to identify structural causes including polyps, adenomyosis, leiomyomas, and endometrial hyperplasia or malignancy. 1

Initial Clinical Assessment

Before imaging, perform these essential steps:

• Assess hemodynamic stability – Check for bleeding that saturates a large pad or tampon hourly for at least 4 hours, which warrants urgent evaluation 1
• Pregnancy test (β-hCG) – Mandatory in all reproductive-age women with abnormal uterine bleeding 1, 2
• Physical examination – Perform speculum examination to visualize the cervix and vagina, excluding cervical or vaginal sources of bleeding, plus bimanual examination to assess uterine size, contour, mobility, and adnexal masses 1

Laboratory Work-Up

Order these tests as part of the initial evaluation:

• Complete blood count – To assess for anemia from blood loss 3
• Thyroid-stimulating hormone (TSH) – To evaluate for thyroid dysfunction as a cause 1, 2
• Prolactin level – To assess for ovulatory dysfunction 1, 2

Imaging Protocol

Transvaginal ultrasound is the primary imaging modality, with transabdominal ultrasound added when needed for complete visualization 1, 2. This combination provides:

• Superior visualization of the endometrium and myometrium 2
• Detection of structural abnormalities: fibroids (most common in women <40 years), endometrial polyps (more common in women >40 years), adenomyosis, and endometrial thickening 1, 4
• Nearly 100% negative predictive value for endometrial cancer when endometrial thickness is <4mm in postmenopausal women 1

When Initial Ultrasound is Indeterminate

Saline infusion sonohysterography (SIS) should be performed when initial ultrasound findings are unclear or suggest intracavitary lesions 2, 5. SIS provides:

• 96-100% sensitivity for uterine and endometrial pathology 1, 5
• 94-100% negative predictive value 5
• 97% accuracy in distinguishing between leiomyomas and endometrial polyps 1

MRI pelvis should be considered only when ultrasound incompletely visualizes the uterus or findings remain indeterminate, with sensitivity up to 79% and specificity up to 89% for endometrial cancer 1

Endometrial Sampling Indications

Endometrial biopsy is mandatory in these situations 5:

• Postmenopausal women with bleeding and endometrial thickness ≥4mm 1
• Premenopausal women with risk factors for endometrial cancer (age >45 years, obesity, diabetes, hypertension, unopposed estrogen exposure, tamoxifen use, Lynch syndrome, or family history of endometrial cancer) 1
• Women with irregular periods regardless of age, to exclude endometrial hyperplasia or malignancy 5

Office-based endometrial sampling using Pipelle or Vabra device has high sensitivity (99.6% and 97.1% respectively) for detecting endometrial carcinoma 5

Critical Pitfalls to Avoid

• Never rely solely on endometrial thickness measurement without tissue sampling when thickness exceeds 11mm in a symptomatic woman 5
• Never accept an inadequate or negative office biopsy as reassuring in a symptomatic patient – the 10% false-negative rate mandates escalation to D&C or hysteroscopy if bleeding persists 5
• Never initiate hormonal therapy before obtaining tissue diagnosis when endometrial sampling is indicated, as this could mask underlying malignancy or hyperplasia 5
• Verify that ultrasound adequately visualized the endometrium and was not obscured by fibroids or adenomyosis 5

Referral Criteria

Refer to gynecology when 1:

• Endometrial sampling shows hyperplasia or malignancy
• Postmenopausal bleeding with endometrial thickness ≥4mm
• Failed medical management