What is the workup and treatment for menorrhagia (heavy menstrual bleeding)?

Workup for Menorrhagia

Begin with a thorough history focusing on bleeding pattern, duration, and volume, followed by pelvic examination, complete blood count, and transvaginal ultrasound as the primary imaging modality. 1

Initial Clinical Assessment

History and Physical Examination

• Document specific bleeding characteristics: cycle length, duration (>7 days suggests menorrhagia), number of pads/tampons used, presence of clots, and impact on daily activities 1
• Assess for anemia symptoms: fatigue, syncope, weakness 2, 3
• Screen for risk factors: age >45 years, obesity, family history of Lynch syndrome or coagulopathy, use of anticoagulants or IUDs 1
• Perform pelvic examination to assess uterine size, masses, and cervical pathology 1

Essential Laboratory Tests

• Complete blood count (CBC) to evaluate for anemia and thrombocytopenia 2, 3
• Thyroid-stimulating hormone (TSH) to exclude thyroid dysfunction 2, 3
• Pregnancy test (β-hCG) in all reproductive-age women to rule out pregnancy-related bleeding 2, 3
• Consider coagulation studies (PT, aPTT, bleeding time) if history suggests bleeding disorder 2

Imaging Workup

First-Line Imaging

Transvaginal ultrasound (TVUS) is the initial imaging modality of choice for evaluating structural causes of menorrhagia in premenopausal women 1. TVUS effectively identifies:

• Uterine leiomyomas (fibroids) - most common in women <40 years 1, 4
• Endometrial polyps - more common in women >40 years 1, 4
• Adenomyosis 1
• Endometrial thickness abnormalities 1

Advanced Imaging When TVUS is Inadequate

Saline infusion sonohysterography (SIS) should be performed when:

• Endometrial cavity detail is needed to distinguish polyps from submucosal fibroids 1
• Assessment of submucosal fibroid intracavitary component is required for treatment planning 1
• TVUS shows thickened endometrium but etiology is unclear 1

MRI with diffusion-weighted imaging is indicated when:

• TVUS cannot adequately visualize the uterus due to large fibroids, adenomyosis, or patient body habitus 1
• Detailed mapping of fibroid location and number is needed for surgical planning 1
• Differentiation between benign and malignant uterine pathology is necessary 1

Endometrial Sampling

Indications for Endometrial Biopsy

Office endometrial biopsy is mandatory in the following scenarios to exclude endometrial hyperplasia or malignancy:

• Age ≥45 years with abnormal uterine bleeding 1
• Age <45 years with risk factors: obesity, chronic anovulation, unopposed estrogen exposure, family history of Lynch syndrome or endometrial cancer 1
• Failed medical management regardless of age 1
• Persistent bleeding despite negative initial workup 1

Important Caveat

Office endometrial biopsy has a 10% false-negative rate 1. If symptoms persist despite a negative biopsy, proceed to:

• Fractional dilation and curettage (D&C) under anesthesia 1
• Hysteroscopy to directly visualize and biopsy focal lesions such as polyps 1

Structural vs. Nonstructural Causes

Structural Causes (Imaging-Detectable)

• Endometrial polyps 1
• Adenomyosis 1
• Leiomyomas (fibroids) 1
• Endometrial hyperplasia 1
• Malignancy (endometrial or myometrial) 1

Nonstructural Causes (Not Imaging-Detectable)

• Coagulopathies 1
• Ovulatory dysfunction 1
• Primary endometrial disorders (abnormal prostaglandins or fibrinolytic system) 1, 5
• Iatrogenic (anticoagulants, IUDs, hormonal medications) 1

Special Considerations

Lynch Syndrome Screening

Universal tumor testing for DNA mismatch repair (MMR) defects is recommended in all endometrial cancer cases 1:

• Perform immunohistochemistry for MLH1, MSH2, MSH6 1
• If MLH1 loss is detected, evaluate for promoter methylation to distinguish germline from epigenetic causes 1
• Refer for genetic counseling if MMR abnormalities detected (excluding methylated MLH1) 1

Postmenopausal Bleeding

Endometrial cancer is the primary concern in postmenopausal women with bleeding 1:

• Endometrial biopsy is mandatory 1
• TVUS to measure endometrial thickness (>4-5mm warrants sampling) 1
• Consider chest imaging and CA-125 if extrauterine disease suspected 1

Common Pitfalls to Avoid

• Do not rely solely on patient's subjective assessment of blood loss - it often does not correlate with actual volume 4
• Do not skip endometrial sampling in high-risk patients even if imaging appears normal 1
• Do not accept a negative office biopsy as definitive in symptomatic patients - proceed to D&C or hysteroscopy 1
• Do not order CT or MRI as first-line imaging - reserve for specific indications when TVUS is inadequate 1