What is the initial evaluation and treatment approach for a patient with Abnormal Uterine Bleeding (AUB), considering factors such as age, parity, medical history, and previous uterine surgeries or conditions like Polycystic Ovary Syndrome (PCOS) or fibroids?

Initial Evaluation and Management of Abnormal Uterine Bleeding

Immediate Assessment

Begin with a pregnancy test (β-hCG) in all reproductive-age women—this is mandatory and non-negotiable, even in perimenopausal patients. 1, 2, 3

Critical First Steps

• Assess hemodynamic stability immediately: urgent evaluation is required if bleeding saturates a large pad or tampon hourly for ≥4 hours. 3
• Perform speculum examination to visualize the cervix and vagina, excluding cervical or vaginal sources of bleeding. 3
• Conduct bimanual examination to assess uterine size, contour, mobility, and adnexal masses. 3
• Palpate the abdomen for enlarged uterus or masses. 3

Essential Laboratory Workup

• Complete blood count with platelets to assess for anemia and coagulopathy. 1
• Thyroid-stimulating hormone (TSH) as part of standard diagnostic workup. 1, 3
• Prolactin levels to evaluate for hyperprolactinemia causing ovulatory dysfunction. 1, 3

First-Line Imaging

Order combined transabdominal and transvaginal ultrasound with Doppler as the initial imaging study—this is the most appropriate approach for identifying structural causes including polyps, adenomyosis, leiomyomas, and endometrial hyperplasia/malignancy. 4, 1, 2, 3

• Transvaginal ultrasound serves as the primary modality for evaluating the endometrium and myometrium with superior visualization. 2, 3
• In perimenopausal women, endometrial thickness <4 mm has nearly 100% negative predictive value for cancer. 3
• Transabdominal imaging is useful when transvaginal approach is limited or for assessing other structural abnormalities. 3

When Initial Ultrasound is Inconclusive

Proceed to saline infusion sonohysterography (SIS) when initial ultrasound findings are unclear or suggest intracavitary lesions—this has 96-100% sensitivity and 94-100% negative predictive value for uterine and endometrial pathology. 4, 3

• SIS distinguishes between leiomyomas and endometrial polyps with 97% accuracy. 3
• SIS confirms intracavitary lesions and determines myometrial involvement with leiomyomas. 3

Endometrial Sampling Indications

Perform endometrial biopsy in perimenopausal women with risk factors for endometrial cancer: obesity, diabetes, hypertension, unopposed estrogen exposure, tamoxifen use, or failed medical management. 3

Critical Pitfall to Avoid

Do not rely on endometrial biopsy alone to rule out focal lesions—it has variable sensitivity and may miss focal pathology that SIS or hysteroscopy would detect. 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

Alternative Medical Options (in descending order of preference)

• Combined hormonal contraceptives (CHCs) are effective for ovulatory dysfunction bleeding and can be combined with NSAIDs to further reduce bleeding volume. 1
• Oral progestins administered for 21 days per month reduce menstrual blood loss and are effective for cyclic heavy bleeding. 1
• Tranexamic acid is a viable option for heavy menstrual bleeding with high efficacy. 1
• NSAIDs may be utilized with hormonal methods and tranexamic acid to decrease menstrual bleeding. 5

Specific Dosing for Progestin Therapy

For abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, norethindrone acetate 2.5-10 mg daily for 5-10 days produces secretory transformation of adequately primed endometrium, with progestin withdrawal bleeding occurring within 3-7 days after discontinuation. 6

Special Population Considerations

Cardiovascular Disease or Post-SCAD Patients

Avoid NSAIDs and tranexamic acid in patients with cardiovascular disease or post-SCAD due to MI and thrombosis risk—the levonorgestrel-releasing IUD becomes the strongly preferred option. 1

• Hormonal therapy is relatively contraindicated in this population despite being first-line for most AUB cases. 1

Patients on Antiplatelet Therapy

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

Patients with PCOS or Ovulatory Dysfunction

Combined hormonal contraceptives are particularly effective for ovulatory dysfunction bleeding, which is the most common cause of DUB in adolescents and women with PCOS. 1

Patients with Known Fibroids or Adenomyosis

Adenomyosis frequently coexists with fibroids and presents with heavy menstrual bleeding, dysmenorrhea, and dyspareunia, commonly affecting women in their 40s. 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

Surgical Management

Endometrial Ablation

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

Critical Informed Consent Requirements

Provide thorough informed consent regarding long-term complications: postablation Asherman syndrome, synechiae, cervical stenosis, and potential delayed endometrial cancer diagnosis. 1

Hysterectomy

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

Management of Treatment Failure

If bleeding persists despite initial medical therapy, further investigation with imaging (MRI or repeat ultrasound) or hysteroscopy is indicated. 4, 1

• MRI pelvis without and with IV contrast is usually appropriate for follow-up imaging when original ultrasound is inconclusive or further characterization is needed. 4

Common Pitfalls to Avoid

• Never skip pregnancy testing, even in perimenopausal women—pregnancy must be excluded. 3
• Do not perform routine endometrial biopsy in all perimenopausal women—target only those with risk factors for endometrial cancer or failed medical management. 3
• Do not miss cervical or vaginal sources of bleeding—always perform speculum examination before attributing bleeding to uterine causes. 3
• Do not use transabdominal ultrasound alone in non-virgins—transvaginal approach provides superior endometrial assessment. 3

Referral Criteria

Refer to gynecology when medical management fails or when endometrial thickness ≥4 mm with persistent bleeding is present. 3