What is the appropriate workup for a patient presenting with irregular menstrual bleeding?

Workup for Irregular Menstrual Bleeding

The appropriate workup for irregular menstrual bleeding should begin with a thorough history, physical examination including pelvic exam, laboratory tests to rule out pregnancy and anemia, and transvaginal ultrasound as the first-line imaging study to evaluate structural causes. 1

Initial Assessment

History - Focus on:

• Pattern of bleeding (regularity, volume, frequency, duration)
• Age (reproductive vs. perimenopausal)
• Pregnancy risk factors
• Medication use (especially hormonal contraceptives)
• Symptoms of structural causes (pain, pressure)
• Symptoms of systemic conditions (thyroid disease, coagulopathies)
• Risk factors for endometrial cancer

Physical Examination:

• Vital signs
• BMI assessment
• Thyroid examination
• Abdominal examination
• Complete pelvic examination including:
  • Speculum examination
  • Cervical inspection
  • Bimanual examination to assess uterine size/shape

Laboratory Testing

First-line Tests:

• Pregnancy test (hCG) 2, 3
• Complete blood count (to assess for anemia) 1, 3
• Thyroid function tests (TSH) 2
• Consider coagulation studies if heavy bleeding (especially in adolescents) to rule out von Willebrand disease 2

Additional Tests Based on Clinical Suspicion:

• Prolactin levels (if galactorrhea or suspected pituitary disorder)
• Hormone levels (FSH, LH, estradiol) if suspecting ovulatory dysfunction
• Endocrine testing if PCOS suspected (testosterone, DHEAS)

Imaging Studies

Transvaginal Ultrasound (TVUS):

• First-line imaging for structural evaluation 1
• Evaluates endometrial thickness, polyps, fibroids, adenomyosis
• Particularly important in women >35 years or with risk factors for endometrial cancer

Additional Imaging Based on TVUS Results:

• Saline infusion sonohysterography (SIS) - if endometrial abnormalities are suspected 2
• MRI - may be appropriate when ultrasound is inconclusive (not first-line) 1, 3

Tissue Sampling

Endometrial Biopsy Indications:

• Women ≥35 years with recurrent anovulatory bleeding 2
• Women <35 years with risk factors for endometrial cancer 2
• Persistent abnormal bleeding unresponsive to medical therapy 2
• Inability to adequately visualize the endometrium on ultrasound 1

Hysteroscopy:

• Second-line procedure after ultrasound 3
• Allows direct visualization and targeted biopsy
• Particularly useful for focal lesions (polyps, submucous fibroids)

Special Considerations

Age-specific Approach:

• Adolescents: Focus on coagulation disorders and anovulation
• Reproductive age: Consider structural causes and hormonal imbalances
• Perimenopausal: Higher suspicion for endometrial hyperplasia/cancer

Contraceptive Users:

• For hormonal contraceptive users with abnormal bleeding, assess compliance first 4
• Rule out pregnancy and organic causes before attributing to contraceptive method 4

Common Pitfalls to Avoid

1. Failure to rule out pregnancy - Always perform pregnancy testing regardless of contraceptive use
2. Missing endometrial cancer - Ensure appropriate endometrial sampling in at-risk women
3. Incomplete ultrasound evaluation - If the endometrium cannot be completely visualized, proceed to endometrial sampling 1
4. Attributing all perimenopausal bleeding to hormonal changes - Structural pathology must still be excluded 5
5. Overlooking coagulation disorders - Particularly important in women with heavy menstrual bleeding 2

Following this systematic approach ensures thorough evaluation of irregular menstrual bleeding, allowing for appropriate diagnosis and management while minimizing the risk of missing significant pathology.