What is the initial evaluation and management of abnormal uterine bleeding?

Initial Evaluation and Management of Abnormal Uterine Bleeding

The initial evaluation of abnormal uterine bleeding (AUB) should begin with transvaginal and transabdominal ultrasound with Doppler, followed by appropriate laboratory testing to identify underlying causes, and then treatment based on the PALM-COEIN classification system. 1

Definition and Classification

Abnormal uterine bleeding is defined as bleeding from the uterus that is abnormal in regularity, volume, frequency, or duration occurring in the absence of pregnancy 1. The PALM-COEIN classification system categorizes causes as:

• Structural causes (PALM):

  • Polyp
  • Adenomyosis
  • Leiomyoma (fibroids)
  • Malignancy and hyperplasia

• Non-structural causes (COEIN):

  • Coagulopathy
  • Ovulatory dysfunction
  • Endometrial disorders
  • Iatrogenic
  • Not yet classified 1

Initial Diagnostic Evaluation

Step 1: Imaging

• Combined transabdominal and transvaginal ultrasound with Doppler is the most appropriate initial imaging study for all patients with AUB 1
• If the uterus is incompletely visualized on ultrasound:
  • MRI of the pelvis without and with contrast is the next appropriate imaging study
  • If a polyp is suspected on initial ultrasound, sonohysterography can be performed instead 1

Step 2: Laboratory Testing

• Pregnancy test (β-hCG)
• Complete blood count
• Thyroid-stimulating hormone (TSH) and prolactin levels
• Coagulation studies if heavy bleeding is present
• Consider hormone levels (FSH, LH, estradiol) in cases of suspected ovulatory dysfunction 1, 2

Step 3: Endometrial Assessment

• Endometrial biopsy is indicated for:

  • Women ≥35 years with recurrent anovulation
  • Women <35 years with risk factors for endometrial cancer
  • Women with excessive bleeding unresponsive to medical therapy 2
  • When endometrial hyperplasia or cancer is suspected 1

• Hysteroscopy should be considered when:

  • Medical treatment fails
  • Focal lesions are suspected
  • Endometrial sampling results are inconclusive 1

Management Based on Etiology

1. Structural Causes (PALM)

Polyps

• Polypectomy via hysteroscopy is the definitive treatment
• Sonohysterography has 96-100% sensitivity for detecting polyps 1

Adenomyosis

• Medical management with hormonal contraceptives
• Levonorgestrel-releasing intrauterine system (LNG-IUD) is effective 2

Leiomyomas (Fibroids)

• Treatment depends on size, location, and symptoms:
  • Medical options: GnRH agonists, selective progesterone receptor modulators, hormonal contraceptives 3
  • Surgical options: myomectomy (for fertility preservation), uterine artery embolization, or hysterectomy (definitive) 3

Malignancy/Hyperplasia

• Hyperplasia without atypia: cyclic or continuous progestin therapy
• Hyperplasia with atypia: refer to gynecologist
• Adenocarcinoma: refer to gynecologic oncologist 2

2. Non-structural Causes (COEIN)

Coagulopathy

• Most commonly von Willebrand disease
• Treatment options:
  • Hormonal methods (all types)
  • Tranexamic acid
  • Consultation with hematology may be needed 2, 4

Ovulatory Dysfunction

• Treat underlying cause (PCOS, thyroid dysfunction, hyperprolactinemia)
• Medical options:
  • Combined hormonal contraceptives
  • Progestin-only contraception
  • Cyclic progestins (21 days per month) 1, 2

Endometrial

• NSAIDs for primary dysmenorrhea
• Tranexamic acid for heavy bleeding 4

Iatrogenic

• Adjust or change medications causing AUB
• Consider alternative contraceptive methods if current method is causing bleeding 1

Treatment Options for Heavy Menstrual Bleeding

First-line Options

1. Levonorgestrel-releasing intrauterine system (LNG-IUD) - most effective medical treatment for menorrhagia 2
2. Combined hormonal contraceptives - regulate cycles and reduce bleeding 1, 2
3. Oral progestins (21 days per month) - effective for cycle regulation 2
4. NSAIDs - reduce bleeding by 20-40%, can be used with hormonal methods 2, 4

Second-line Options

1. Tranexamic acid - FDA-approved for ovulatory bleeding but expensive 2
2. GnRH agonists - for short-term use, especially pre-surgical 4

Surgical Options (when medical management fails)

1. Endometrial ablation - for women who have completed childbearing
2. Polypectomy or fibroidectomy - for specific structural causes
3. Hysterectomy - definitive treatment when other options fail 2

Management of Acute Heavy Bleeding

For acute abnormal uterine bleeding:

1. Parenteral estrogen
2. Multi-dose combined oral contraceptive regimen
3. Multi-dose progestin-only regimen
4. Tranexamic acid 4

Common Pitfalls to Avoid

• Failure to rule out pregnancy - always perform pregnancy testing in reproductive-age women
• Missing endometrial cancer - ensure appropriate endometrial sampling in high-risk patients
• Incomplete evaluation of the endometrium - if ultrasound cannot fully visualize the endometrium, proceed to MRI or sonohysterography 1
• Overlooking coagulopathies - consider bleeding disorders, especially in adolescents with heavy menstrual bleeding
• Treating symptoms without identifying the cause - complete the diagnostic evaluation before initiating long-term therapy

By following this systematic approach to evaluation and management of abnormal uterine bleeding, clinicians can effectively diagnose and treat this common condition, improving patient outcomes and quality of life.