How to diagnose and manage abnormal uterine bleeding in a non-pregnant woman of reproductive age with potential menstrual irregularities or gynecological issues?

Diagnosis and Management of Abnormal Uterine Bleeding in Non-Pregnant Women

Immediate Assessment and Stabilization

Begin by assessing hemodynamic stability—if bleeding saturates a large pad or tampon hourly for at least 4 hours, urgent evaluation is required. 1

Physical Examination Priorities

• Perform speculum examination to visualize the cervix and vagina, excluding cervical or vaginal sources before attributing bleeding to uterine causes 1
• Conduct bimanual examination to assess uterine size, contour, mobility, and detect adnexal masses 1
• Palpate the abdomen for enlarged uterus or masses 1

Essential Laboratory Workup

Every reproductive-age woman with abnormal uterine bleeding must have a pregnancy test (β-hCG), regardless of age or perceived risk—this is mandatory even in perimenopausal women. 1, 2

Standard Laboratory Panel

• Thyroid-stimulating hormone (TSH) to evaluate thyroid dysfunction as a cause 1
• Prolactin levels to assess for hyperprolactinemia causing ovulatory dysfunction 1
• Complete blood count with platelets to evaluate for anemia and coagulopathy 3
• Hemoglobin and iron levels in cases of heavy bleeding 4

First-Line Imaging Strategy

Combined transabdominal and transvaginal ultrasound with Doppler is the most appropriate initial imaging study for identifying structural causes including polyps, adenomyosis, leiomyomas, and endometrial hyperplasia/malignancy. 1, 2

Imaging Interpretation

• Transvaginal ultrasound serves as the primary modality for evaluating the endometrium and myometrium 1
• Endometrial thickness <4 mm in perimenopausal women has nearly 100% negative predictive value for cancer 1, 2
• Transabdominal imaging is useful when transvaginal approach is limited 1

Advanced Diagnostic Procedures

When to Order Saline Infusion Sonohysterography (SIS)

Perform SIS when initial ultrasound findings are unclear or suggest intracavitary lesions—it has 96-100% sensitivity and 94-100% negative predictive value for uterine and endometrial pathology. 1

• SIS distinguishes between leiomyomas and endometrial polyps with 97% accuracy 1
• SIS confirms intracavitary lesions and determines myometrial involvement with leiomyomas 1
• SIS is more accurate than transvaginal ultrasonography alone for endometrial assessment 1

Endometrial Biopsy Indications

Perform endometrial biopsy in perimenopausal women with the following risk factors for endometrial cancer: 1

• Obesity 1, 2
• Diabetes 1, 2
• Hypertension 1, 2
• Unopposed estrogen exposure 1, 2
• Tamoxifen use 1, 2
• Lynch syndrome or family history of endometrial cancer 2
• Failed medical management 1

When to Proceed to Hysteroscopy

Reserve hysteroscopy for cases where medical treatment has failed, imaging suggests focal lesions possibly missed by endometrial sampling, or SIS identifies intracavitary masses requiring surgical management. 1, 3

• Hysteroscopy allows direct visualization of the endometrial cavity and endocervix, diagnosing focal lesions possibly missed by endometrial sampling 1, 3

Medical Management Algorithm

First-Line Medical 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, 5

Alternative Medical Options (in order of preference)

• Combined hormonal contraceptives (CHCs) are effective for ovulatory dysfunction bleeding and can be combined with NSAIDs to reduce bleeding volume further 3, 5
• Oral progestins administered for 21 days per month for menstrual blood loss reduction, effective for cyclic heavy bleeding 3, 5
• Tranexamic acid is a viable option for heavy menstrual bleeding with high efficacy 3, 5
• NSAIDs may be utilized with hormonal methods and tranexamic acid to decrease menstrual bleeding 3, 5

Critical Caveat for Special Populations

In women with cardiovascular disease or post-SCAD, avoid NSAIDs and tranexamic acid due to MI and thrombosis risk—the levonorgestrel-releasing IUD becomes the preferred option. 2, 3

For patients on antiplatelet therapy, reassess the indication for ongoing antiplatelet therapy and discontinue if appropriate before initiating treatment, with progestin-eluting IUDs preferred due to minimal systemic absorption. 2, 3

For women on anticoagulation therapy (approximately 70% experience heavy menstrual bleeding), consider progestin-only methods or GnRH agonists. 2, 5

Surgical Management

When Medical Management Fails

If bleeding persists despite initial medical therapy, further investigation with imaging or hysteroscopy is indicated. 3

Surgical Options

• Endometrial ablation is a less invasive alternative to hysterectomy with efficacy comparable to LNG-IUD 3
• Hysterectomy is the most appropriate treatment when medical management fails or is contraindicated, providing complete resolution of symptoms and significantly better health-related quality of life 2, 3

Endometrial Ablation Warnings

Endometrial ablation has long-term complications including postablation Asherman syndrome, synechiae, cervical stenosis, and potential delayed endometrial cancer diagnosis—thorough informed consent is required. 3

Referral Criteria to Gynecology

Refer to gynecology when: 2

• Failed medical management occurs 2
• Endometrial thickness ≥4 mm with persistent bleeding is present 2
• Endometrial sampling shows hyperplasia or malignancy 2
• Postmenopausal bleeding with endometrial thickness ≥4 mm 2

Common Pitfalls to Avoid

• Never skip pregnancy testing, even in perimenopausal women—pregnancy must be excluded 1
• Do not rely on transabdominal ultrasound alone in non-virgins, as transvaginal approach provides superior endometrial assessment 1
• Do not perform routine endometrial biopsy in all perimenopausal women—target those with risk factors for endometrial cancer or failed medical management 1
• Do not miss cervical or vaginal sources of bleeding—always perform speculum examination before attributing bleeding to uterine causes 1
• Do not use endometrial biopsy alone to rule out focal lesions, as it has variable sensitivity—SIS has high sensitivity and negative predictive value for assessing intracavitary pathology 3