What is the appropriate evaluation and management of abnormal uterine bleeding in a reproductive‑age woman?

Evaluation and Management of Abnormal Uterine Bleeding in Reproductive-Age Women

Immediate Assessment

All reproductive-age women with abnormal uterine bleeding must first have a pregnancy test (β-hCG), as pregnancy-related complications are the most critical diagnosis to exclude in this population. 1

Assess for hemodynamic instability immediately—urgent evaluation is required if bleeding saturates a large pad or tampon hourly for at least 4 hours. 1

Diagnostic Workup

Essential Initial Testing

• Pregnancy test (β-hCG) - mandatory first step 1
• Combined transabdominal and transvaginal ultrasound with Doppler - this is the first-line imaging study for identifying structural causes including polyps, adenomyosis, leiomyomas, and endometrial hyperplasia/malignancy 1, 2
• Thyroid-stimulating hormone and prolactin levels - to evaluate endocrine causes 1
• Complete blood count with platelets - to assess anemia and coagulopathy 3

Physical Examination Specifics

• Abdominal examination to palpate for enlarged uterus or masses and assess hemodynamic stability 1
• Speculum examination to visualize cervix and vagina, excluding cervical or vaginal bleeding sources 1
• Bimanual examination to assess uterine size, contour, mobility, and adnexal masses 1

Classification Using PALM-COEIN System

The PALM-COEIN framework categorizes causes as: 1, 3

Structural (PALM):

• Polyp - more common in women over 40 1
• Adenomyosis - frequent in premenopausal women in their 40s, often coexists with fibroids 1, 3
• Leiomyoma - most common structural cause in women under 40 1
• Malignancy/hyperplasia - requires endometrial biopsy in women >45 years or those with risk factors (obesity, diabetes, hypertension, unopposed estrogen, tamoxifen, Lynch syndrome) 1, 4

Non-structural (COEIN):

• Coagulopathy - screen adolescents with menorrhagia and those with high-risk factors for von Willebrand disease 5
• Ovulatory dysfunction - causes irregular, heavy bleeding 1
• Endometrial disorders - molecular deficiencies in endometrial hemostasis 1
• Iatrogenic - anticoagulation (70% experience heavy bleeding), IUDs, hormonal medications 1
• Not yet classified 1

Advanced Imaging When Needed

• Saline infusion sonohysterography has 96-100% sensitivity and 94-100% negative predictive value for uterine pathology, distinguishing leiomyomas from polyps with 97% accuracy 1
• MRI pelvis when ultrasound incompletely visualizes the uterus or findings are indeterminate (sensitivity 79%, specificity 89% for endometrial cancer) 1

Endometrial Sampling Indications

Endometrial biopsy is mandatory for: 1, 4

• All women >45 years with AUB
• Women ≤45 years with risk factors for endometrial cancer (obesity, diabetes, hypertension, unopposed estrogen, tamoxifen, Lynch syndrome)
• Postmenopausal bleeding with endometrial thickness ≥4 mm on ultrasound

Critical caveat: Endometrial biopsy alone cannot rule out focal lesions due to variable sensitivity—saline infusion sonohysterography should be used for intracavitary pathology assessment. 3

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. 3

Alternative Medical Options (in descending order of preference):

1. Combined hormonal contraceptives (CHCs) - particularly effective for ovulatory dysfunction bleeding; can be combined with NSAIDs for additional bleeding reduction 3

2. Oral progestins - administered 21 days per month for cyclic heavy bleeding related to menstrual cycle 3

3. Tranexamic acid - viable option with high efficacy for heavy menstrual bleeding 3

4. NSAIDs - can reduce bleeding volume when combined with hormonal therapy 3

Critical Contraindications for Special Populations

In women with cardiovascular disease or post-SCAD: 1, 3

• Avoid NSAIDs and tranexamic acid due to MI and thrombosis risk
• LNG-IUD becomes the mandatory preferred option due to minimal systemic absorption
• Hormonal therapy is relatively contraindicated despite being first-line for most AUB cases

In women on antiplatelet therapy: 1, 3

• Reassess indication for ongoing antiplatelet therapy and discontinue if appropriate
• Progestin-eluting IUDs preferred due to minimal systemic absorption

In women on anticoagulation: 1

• Approximately 70% experience heavy menstrual bleeding
• Rivaroxaban associated with prolonged bleeding (>8 days) in 27% of cases

Surgical Management

When to Proceed with Surgery

If bleeding persists despite initial medical therapy, perform hysteroscopy to visualize the endometrial cavity and diagnose focal lesions potentially missed by endometrial sampling. 3

Surgical Options (in order of invasiveness):

1. Endometrial ablation - less invasive alternative to hysterectomy with efficacy comparable to LNG-IUD 3

   • Important caveat: Long-term complications include postablation Asherman syndrome, synechiae, cervical stenosis, and potential delayed endometrial cancer diagnosis—thorough informed consent required 3

2. Hysterectomy - definitive treatment providing complete symptom resolution and significantly better health-related quality of life compared to other therapies 1, 3

   • Most appropriate when medical management fails or is contraindicated
   • Particularly indicated in postmenopausal women with symptomatic fibroids

Gynecology Referral Criteria

Refer to gynecologist when: 1

• Failed medical management
• Endometrial sampling shows hyperplasia or malignancy
• Postmenopausal bleeding with endometrial thickness ≥4 mm

Common Pitfalls to Avoid

• Never assume non-pregnancy status without testing - pregnancy complications are the most critical diagnosis to exclude 1
• Do not rely on endometrial biopsy alone to exclude focal lesions—use saline infusion sonohysterography for complete evaluation 3
• Do not prescribe NSAIDs or tranexamic acid to patients with cardiovascular disease—use LNG-IUD instead 1, 3
• Do not delay endometrial sampling in women >45 years or those with risk factors—malignancy must be excluded 1, 4
• Avoid using ascorbic acid for AUB treatment as it is not recommended by evidence-based guidelines 3