Abnormal Uterine Bleeding Definition and Classification

Introduction to Abnormal Uterine Bleeding

• Abnormal uterine bleeding (AUB) is defined as bleeding from the uterus that is abnormal in regularity, volume, frequency, or duration and occurs in the absence of pregnancy, as defined by the American College of Radiology 1, 2, 3, 4

Classification System

• The International Federation of Gynecology and Obstetrics (FIGO) developed the PALM-COEIN classification system to describe uterine bleeding abnormalities in women of reproductive age, which includes structural causes (PALM) and non-structural causes (COEIN) 5
• Structural causes (PALM) include polyps, adenomyosis, leiomyoma, and malignancy and hyperplasia, as classified by the American College of Radiology 5, 6
• Non-structural causes (COEIN) include coagulopathy, ovulatory dysfunction, endometrial disorders, iatrogenic causes, and not yet classified, as defined by the American College of Radiology 5, 6

Clinical Presentations and Causes

• Reproductive-age women often experience AUB due to structural causes such as polyps, adenomyosis, and leiomyomas, as well as non-structural causes like ovulatory dysfunction, coagulopathies, and iatrogenic causes, according to the American College of Radiology 1, 3, 5, 6
• Perimenopausal women often experience AUB due to anovulation, but structural causes must be ruled out, as recommended by the American College of Radiology 5, 6
• Postmenopausal women are at risk for endometrial cancer, which is the most serious etiology and the main focus of evaluation, as stated by the American College of Radiology 1, 3, 4

Diagnostic Approach

• The evaluation of AUB typically includes laboratory tests, such as pregnancy test, thyroid-stimulating hormone, and prolactin levels, as well as imaging studies like transvaginal ultrasound (TVUS), as recommended by the American College of Radiology 5, 6
• Additional studies, such as saline infusion sonohysterography, hysteroscopy with biopsy, and MRI, may be indicated in certain cases, as suggested by the American College of Radiology 2, 3, 4

Management Considerations

• Medical treatments for ovulatory dysfunction include progestin-only contraception, combined hormonal contraception, and antifibrinolytic agents, as recommended by the American College of Radiology 6
• Surgical options, such as endometrial ablation and hysterectomy, may be considered when medical treatment fails or is contraindicated, as stated by the American College of Radiology 5

Important Caveats

• Endometrial sampling is necessary in patients with risk factors for endometrial cancer, as recommended by the American College of Radiology 6
• When TVUS cannot completely evaluate the endometrium, MRI or endometrial sampling should be considered, as suggested by the American College of Radiology 1, 2, 3

Management of Dysfunctional Uterine Bleeding

Initial Approach and Medical Management

• Medical management should be trialed first for dysfunctional uterine bleeding before considering hysterectomy, with hysterectomy being appropriate as a definitive treatment when medical management fails or is contraindicated, as recommended by the American College of Radiology 7, 8, 9
• First-line medical management should be attempted before pursuing invasive therapies such as hysterectomy, according to the American College of Radiology 8, 9
• NSAIDs and estrogen-progestin oral contraceptives can effectively reduce bleeding symptoms, as stated by the American College of Radiology 7
• Tranexamic acid is a non-hormonal alternative that may reduce bleeding symptoms in patients with fibroids, as reported by the American College of Radiology 7
• GnRH antagonists (elagolix, linzagolix, relugolix) can also effectively reduce bleeding symptoms, according to the American College of Radiology 7
• Both GnRH agonists and antagonists can significantly reduce fibroid volume when fibroids are present, as found by the American College of Radiology 7

Surgical Management and Considerations

• Hysterectomy remains the most common treatment for uterine fibroids, accounting for three-quarters of fibroid treatment in the United States, as noted by the American College of Radiology 7
• Hysterectomy provides definitive resolution of all fibroid-related symptoms for patients with heavy uterine bleeding, as stated by the American College of Radiology 7
• A meta-analysis comparing UAE with hysterectomy demonstrated significantly greater short-term benefits of UAE but increased percentage of long-term reintervention, as reported by the American College of Radiology 10
• Hysterectomy is usually appropriate as a next step for postmenopausal patients with uterine fibroids who are symptomatic with heavy uterine bleeding, according to the American College of Radiology 9
• Patient age and fertility desires are critical factors in decision-making, as emphasized by the American College of Radiology 9
• Medical menopause with GnRH agonists/antagonists is temporary and symptoms return after discontinuation, as noted by the American College of Radiology 10
• Hysterectomy provides definitive resolution but carries surgical risks, as stated by the American College of Radiology 7
• Studies have shown hysterectomy provides significantly better health-related quality-of-life advantage compared to other therapies, as reported by the American College of Radiology 10

Management of Symptomatic Uterine Leiomyomas

Diagnosis and Treatment

• Adenomyosis frequently coexists with uterine fibroids and presents with heavy menstrual bleeding, dysmenorrhea, and dyspareunia, and is common in women in their 40s, contributing significantly to menorrhagia and anemia, according to the American College of Radiology 11
• Hysterectomy is the most appropriate definitive treatment for symptomatic uterine leiomyomas, providing complete resolution of fibroid-related symptoms and eliminating risk of recurrence, as recommended by the American College of Radiology 11
• The least invasive surgical route should be chosen for hysterectomy based on uterine size and surgical expertise, as suggested by the American College of Radiology 11

Treatment of Excessive Uterine Bleeding During Menstruation (Menorrhagia)

Initial Management

• The American College of Radiology recommends starting with medical management using a levonorgestrel-releasing intrauterine device (IUD), tranexamic acid, NSAIDs, or combined oral contraceptives before considering surgical options, as these therapies effectively reduce menstrual blood loss by 20-60% and significantly improve quality of life 12

First-Line Medical Management

• The American College of Radiology suggests that levonorgestrel-releasing intrauterine device (IUD) is the most effective medical treatment, with efficacy comparable to endometrial ablation or hysterectomy, and should be strongly considered as first-line therapy for women desiring uterus preservation 12
• Combined oral contraceptives effectively reduce menstrual bleeding and are appropriate first-line options, particularly in younger women who also desire contraception 12, 13
• Tranexamic acid reduces menstrual blood loss by 20-60% and is an effective non-hormonal alternative, particularly useful in patients with fibroids or those who cannot use hormonal therapy 12

Surgical Management

• Uterine artery embolization (UAE) is effective for patients with fibroids and adenomyosis who desire uterus-preserving therapy, with 94% short-term symptom improvement and 85% long-term improvement, though 7% require subsequent hysterectomy for persistent symptoms 12
• Hysterectomy provides definitive resolution of all fibroid-related symptoms and eliminates recurrence risk, accounting for three-quarters of fibroid treatment in the United States 12
• Choose the least invasive surgical route (vaginal > laparoscopic/robotic > abdominal) based on uterine size and surgical expertise, as vaginal and laparoscopic approaches are associated with shorter hospital stays, faster recovery, and lower complication rates compared to abdominal hysterectomy 12

Special Considerations

• Women on anticoagulation (particularly NOACs like rivaroxaban) have increased risk of abnormal uterine bleeding (27% vs 8.3% with warfarin), requiring careful counseling and monitoring, especially during the first cycles after initiation 14