What are the guidelines for managing Abnormal Uterine Bleeding (AUB)?

Management of Abnormal Uterine Bleeding

Diagnostic Classification and Initial Workup

Use the PALM-COEIN classification system to systematically categorize the bleeding cause into structural (Polyp, Adenomyosis, Leiomyoma, Malignancy/hyperplasia) versus non-structural (Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not classified) etiologies 1, 2.

Essential Initial Testing

• Pregnancy test (β-hCG) is mandatory in all reproductive-age women before any further evaluation or treatment 1, 3
• Order complete blood count with platelets to assess for anemia and thrombocytopenia 1
• Measure thyroid-stimulating hormone (TSH) and prolactin levels to exclude thyroid dysfunction and hyperprolactinemia 1, 3
• Obtain detailed menstrual history documenting regularity, duration, frequency, and volume of bleeding 3
• Assess for signs of hyperandrogenism (acne, hirsutism) suggesting polycystic ovary syndrome 3

Imaging Strategy

• Perform combined transabdominal and transvaginal ultrasound with Doppler as first-line imaging for all patients with AUB 4, 1
• Order transvaginal ultrasound if structural etiology is suspected or symptoms persist despite treatment 1
• In postmenopausal women, endometrial thickness ≥5 mm on transvaginal ultrasound mandates endometrial tissue sampling, while thickness <4 mm has nearly 100% negative predictive value for cancer 2
• Use saline infusion sonohysterography when initial ultrasound is inconclusive or further characterization is needed, as it has high sensitivity and negative predictive value for intracavitary pathology 4, 1
• Do not rely on endometrial biopsy alone to rule out focal lesions due to variable sensitivity 1

Medical Management Algorithm

First-Line Treatment

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, 5, 6.

The LNG-IUD should be your default choice because:

• It demonstrates the highest efficacy for heavy menstrual bleeding 1
• It has minimal systemic absorption, making it safer for patients with cardiovascular disease or on antiplatelet therapy 1
• It provides long-term management without daily compliance requirements 6

Alternative Medical Options (When LNG-IUD is Declined or Contraindicated)

Combined hormonal contraceptives (CHCs) are effective for ovulatory dysfunction bleeding and can be combined with NSAIDs to further reduce bleeding volume 1, 5. Use CHCs as first-line in adolescents with mild to moderate anovulatory bleeding 3.

Oral progestins administered for 21 days per month reduce menstrual blood loss and are effective for women with cyclic heavy bleeding 1, 5.

Tranexamic acid is a viable option with high efficacy for heavy menstrual bleeding 1, 5. However, avoid tranexamic acid in patients with cardiovascular disease or post-SCAD due to thrombosis risk 1.

NSAIDs may be utilized with hormonal methods to decrease menstrual bleeding 5. However, avoid NSAIDs in patients with cardiovascular disease or post-SCAD due to MI risk 1.

Special Population Considerations

In patients with cardiovascular disease or post-SCAD, the LNG-IUD becomes the mandatory preferred option because NSAIDs and tranexamic acid carry unacceptable MI and thrombosis risks 1.

For patients on antiplatelet therapy:

• Reassess the indication for ongoing antiplatelet therapy and discontinue if appropriate before initiating AUB treatment 1
• Prefer progestin-eluting IUDs due to minimal systemic absorption 1

In adolescents, 95% of AUB is dysfunctional (anovulatory), though systematic evaluation is required to exclude underlying systemic or oncological diseases 2. Use combined hormonal contraceptives as first-line for mild to moderate bleeding, with progestin-only options (oral, injectable, or intrauterine) as alternatives 3.

Surgical Management

When to Escalate to Surgery

If bleeding persists despite initial medical therapy, perform hysteroscopy to visualize the endometrial cavity and diagnose focal lesions potentially missed by endometrial sampling 1.

Surgical Options

Endometrial ablation is a less invasive alternative to hysterectomy with efficacy comparable to LNG-IUD 1. However, provide thorough informed consent regarding long-term complications including postablation Asherman syndrome, synechiae, cervical stenosis, and potential delayed endometrial cancer diagnosis 1.

Hysterectomy is the definitive treatment when medical management fails or is contraindicated, particularly in postmenopausal women with symptomatic fibroids 1. Consider hysterectomy for patients who have completed childbearing and desire permanent resolution 1.

Hysteroscopic removal of polyps is rarely needed in adolescents but may be considered for bleeding with structural abnormalities 3.

Critical Pitfalls to Avoid

• Never skip pregnancy testing in reproductive-age women—this is non-negotiable 1, 3
• Do not use endometrial biopsy alone to exclude focal lesions; it has variable sensitivity 1
• Avoid NSAIDs and tranexamic acid in cardiovascular disease patients due to MI and thrombosis risk 1
• Do not recommend ascorbic acid for AUB—it lacks evidence-based support 1
• Sonohysterography cannot distinguish between benign endometrial pathology and endometrial cancer with certainty; always follow up with endometrial sampling or hysteroscopy when pathology is suspected 4
• In postmenopausal women, endometrial cancer is the primary concern and must be the focus of evaluation 2

Management of Treatment Failure

If bleeding persists despite medical therapy:

• Perform hysteroscopy to diagnose focal lesions possibly missed by endometrial sampling 1
• Consider advanced imaging with MRI pelvis without and with IV contrast for further characterization 4
• Adjust treatment based on response and tolerability 3
• Escalate to surgical management (endometrial ablation or hysterectomy) when medical options are exhausted 1