How should abnormal uterine bleeding (AUB) be evaluated and managed initially in a hemodynamically stable patient with heavy menstrual loss?

Initial Evaluation and Management of Abnormal Uterine Bleeding in Hemodynamically Stable Patients

For hemodynamically stable patients with heavy menstrual bleeding, the levonorgestrel-releasing intrauterine device (LNG-IUD) is the most effective first-line medical treatment, reducing menstrual blood loss by 71-95% with efficacy comparable to endometrial ablation. 1

Initial Diagnostic Workup

Mandatory Laboratory Testing

• Pregnancy test (β-hCG) must be performed in all reproductive-age women before proceeding with any further evaluation or treatment 1, 2
• Complete blood count with platelets to assess for anemia and thrombocytopenia 1
• Thyroid-stimulating hormone (TSH) and prolactin levels to exclude endocrine causes of anovulation 1, 2

Classification Framework

• Use the PALM-COEIN classification system to systematically categorize the bleeding cause 1, 3:
  • Structural causes (PALM): Polyp, Adenomyosis, Leiomyoma, Malignancy/hyperplasia 1, 3
  • Non-structural causes (COEIN): Coagulopathy, Ovulatory dysfunction, Endometrial disorders, Iatrogenic, Not yet classified 1, 3

Imaging Strategy

• Transvaginal ultrasound (TVUS) is the first-line imaging modality and should be ordered if structural etiology is suspected or symptoms persist despite initial treatment 1, 2
• Saline infusion sonohysterography has 96-100% sensitivity for intracavitary pathology and can distinguish leiomyomas from polyps with 97% accuracy 2
• Critical pitfall: Endometrial biopsy alone should not be used to rule out focal lesions due to variable sensitivity 1

Endometrial Sampling Indications

• Mandatory endometrial biopsy for:
  • Age ≥45 years 2
  • Age <45 with risk factors: obesity, diabetes, hypertension, unopposed estrogen exposure, tamoxifen use, Lynch syndrome 2
  • Chronic anovulation with obesity and diabetes, even if younger than 35 years, due to heightened endometrial cancer risk 2

Medical Management Algorithm

First-Line Treatment Options (Ranked by Efficacy)

1. Levonorgestrel-Releasing IUD (Most Effective)

• Reduces menstrual blood loss by 71-95% 1
• Efficacy equivalent to endometrial ablation 1, 3
• Preferred option for patients with cardiovascular disease or post-SCAD because NSAIDs and tranexamic acid carry MI and thrombosis risk in this population 1
• Minimal systemic absorption makes it ideal for patients on antiplatelet therapy 1

2. Tranexamic Acid

• Reduces menstrual blood loss by 20-60% 3
• Effective non-hormonal alternative, particularly useful in patients with fibroids 3
• Contraindicated in cardiovascular disease or post-SCAD due to thrombosis risk 1
• Appropriate when hormonal therapy is contraindicated or immediate pregnancy is desired 4

3. Combined Hormonal Contraceptives (CHCs)

• Effective for ovulatory dysfunction bleeding 1
• Can be combined with NSAIDs to further reduce bleeding volume 1
• Appropriate first-line option, particularly in younger women desiring contraception 3

4. Oral Progestins

• Administer for 21 days per month for menstrual blood loss reduction 1
• Effective for women with cyclic heavy bleeding related to menstrual cycle 1
• Appropriate alternative when estrogen is contraindicated 2

5. NSAIDs

• Reduce bleeding by 20-50%, most effective for ovulatory menorrhagia 2
• Avoid in cardiovascular disease or post-SCAD due to MI risk 1

Special Population Considerations

Patients with Cardiovascular Disease

• Avoid NSAIDs and tranexamic acid due to MI and thrombosis risk 1
• Levonorgestrel-releasing IUD becomes the preferred option 1
• Hormonal therapy is relatively contraindicated despite being first-line for most AUB cases 1

Patients on Anticoagulation

• Women on NOACs (e.g., rivaroxaban) have 27% risk of AUB versus 8.3% with warfarin 3
• Reassess indication for ongoing antiplatelet therapy and discontinue if appropriate before initiating AUB treatment 1
• Progestin-eluting IUDs preferred due to minimal systemic absorption 1

Perimenopausal Women

• Higher risk for endometrial hyperplasia/cancer; lower threshold for endometrial sampling 2
• Anovulation is common but structural causes must be ruled out 3

Management of Treatment Failure

When to Investigate Further

• If bleeding persists despite initial medical therapy, further investigation with imaging or hysteroscopy is indicated 1
• Hysteroscopy allows visualization of endometrial cavity and endocervix, diagnosing focal lesions possibly missed by endometrial sampling 1

Surgical Options

Endometrial Ablation

• Less invasive alternative to hysterectomy with efficacy comparable to LNG-IUD 1
• Appropriate for completed childbearing 2
• Important caveat: Long-term complications include postablation Asherman syndrome, synechiae, cervical stenosis, and potential delayed endometrial cancer diagnosis; thorough informed consent required 1

Hysterectomy (Definitive Treatment)

• Most appropriate when medical management fails or is contraindicated 1, 3
• Particularly indicated in postmenopausal women with symptomatic fibroids 1
• Provides significantly better health-related quality of life compared to other therapies 3, 2
• Choose the least invasive surgical route (vaginal > laparoscopic/robotic > abdominal) based on uterine size and surgical expertise 3

Common Clinical Scenarios

Adenomyosis

• Frequently coexists with fibroids 1, 3
• Presents with heavy menstrual bleeding, dysmenorrhea, and dyspareunia 1
• Common in women in their 40s 1

Chronic Anovulation (e.g., PCOS)

• Irregular cycles every 3-4 months with prolonged heavy bleeding 2
• Obesity and diabetes are risk factors 2
• Unopposed estrogen exposure markedly raises risk of endometrial hyperplasia and cancer 2
• Endometrial sampling indicated even in younger patients with obesity and diabetes due to heightened cancer risk 2