What is the initial step in managing a patient with abnormal uterine bleeding?

Initial Management of Abnormal Uterine Bleeding

The initial step in managing a patient with abnormal uterine bleeding should be a thorough assessment for hemodynamic stability, followed by combined transabdominal and transvaginal ultrasound with Doppler as the first-line imaging study. 1

Initial Assessment

Hemodynamic Stability Evaluation

• Promptly assess for signs of hypovolemia and potential hemodynamic instability 2
• Urgent evaluation is warranted for patients with bleeding that saturates a large pad or tampon hourly for at least 4 hours 1
• All reproductive-age women with abnormal uterine bleeding should be tested for pregnancy 1

History and Physical Examination Focus Points

• Determine bleeding pattern: regularity, volume, frequency, and duration 3
• Identify potential causes of anovulation: adolescence, perimenopause, lactation, hyperandrogenic conditions, hypothalamic dysfunction, hyperprolactinemia, thyroid disease, primary pituitary disease, premature ovarian failure 1
• Assess medication use, particularly antiplatelet or anticoagulant therapy 1

Diagnostic Approach

First-Line Imaging

• Combined transabdominal and transvaginal ultrasound with Doppler is the most appropriate initial imaging study 1
• This helps identify structural causes of abnormal uterine bleeding such as polyps, adenomyosis, leiomyomas, and endometrial hyperplasia/malignancy 3, 4

Laboratory Testing

• Pregnancy test (β-hCG) 1
• Thyroid-stimulating hormone and prolactin levels 1
• Consider coagulation studies if heavy menstrual bleeding is present 5

Follow-up Imaging (if initial ultrasound is inconclusive)

• If polyp is suspected on initial ultrasound: sonohysterography 1
• If uterus is incompletely visualized: MRI of pelvis without and with contrast 1
• Hysteroscopy for direct visualization of endometrial cavity when focal lesions are suspected 1

Classification of Abnormal Uterine Bleeding

PALM-COEIN Classification System

• Structural causes (PALM): Polyp, Adenomyosis, Leiomyoma (submucosal or other), Malignancy and hyperplasia 1
• Non-structural causes (COEIN): Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not yet classified 1

Common Pitfalls and Caveats

• Transvaginal ultrasound is not typically recommended in virgins; transabdominal imaging may be used but has less sensitivity for endometrial assessment 1
• Uterine position, patient body habitus, and presence of adenomyosis or leiomyomas can limit visualization during ultrasound 1
• Endometrial biopsy is preferred over dilation and curettage for diagnosing endometrial hyperplasia or cancer due to being less invasive, safer, and lower cost 1
• Women with von Willebrand's disease may be misdiagnosed as having dysfunctional uterine bleeding; this disorder is present in approximately 1% of the population 6

Special Considerations

Abnormal Bleeding with Antiplatelet Therapy

• In patients on antiplatelet therapy with abnormal uterine bleeding, reassess the indication for ongoing antiplatelet therapy and consider discontinuation if appropriate 1
• Avoid nonsteroidal anti-inflammatory drugs and tranexamic acid in patients with cardiovascular disease (such as SCAD) due to association with MI and thrombosis 1

By following this structured approach to the initial management of abnormal uterine bleeding, clinicians can efficiently identify the underlying cause and develop an appropriate treatment plan that addresses both the acute bleeding episode and long-term management.