Abnormal uterine bleeding (AUB) is a broad term for variations in normal menses. Normal duration of menstrual flow is 5 days, with normal menstrual cycles lasting 21 to 35 days. Heavy menstrual bleeding with normal cycles, historically called menorrhagia, is a large volume of menstrual blood loss quantified as >80 ml per cycle. Bleeding also may be prolonged, intermenstrual, frequent, and irregular. This language replaces prior terms such as metrorrhagia (bleeding between cycles); polymenorrhea (menses <21 days apart); and oligomenorrhea (menses >35 days apart).^1-3

The PALM-COEIN classification of AUB was adopted in 2011 to standardize terminology and reflect etiology: Polyp, Adenomyosis, Leiomyoma, Malignancy and hyperplasia, Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, and Not yet classified. The PALM-COEIN terminology is used to classify the etiology of the bleeding; for instance, AUB-P would refer to AUB due to polyps.^1-4

Menorrhagia

Menometrorrhagia

Dysfunctional uterine bleeding

Irregular menstrual cycle

Age, age at menarche or menopause, menstrual bleeding patterns, severity of bleeding, pain, underlying medical conditions, surgical history, medications, family history, hirsutism, acne, symptoms of thyroid dysfunction or other endocrinopathies^1-4

1. If heavy bleeding since menarche, screen for signs and symptoms of hemostatic disorder, including postpartum hemorrhage, surgery-related bleeding, bleeding from dental work, easy bruising, epistaxis, and frequent gum bleeding³
2. Physical examination: Weight, hirsutism, acne, thyroid nodules, signs of insulin resistance (acanthosis nigricans), signs of bleeding disorder (petechiae, ecchymoses, pallor, swollen joints), pelvic examination including external, speculum, and bimanual examinations

• PALM-COEIN
• Additional etiologies: Pregnancy/miscarriage; atrioventricular (AV) malformations; cervical/endometrial infections; foreign body, such as intrauterine device (IUD) malposition; use of hormones; anticoagulation medications; severe kidney or liver disease; thyroid disorder^3-4

In addition to the PALM-COEIN classification, it is also important to consider etiologies as listed earlier, including urinary and GI tract sources.

Differential diagnosis of AUB can be further narrowed by age.

• AUB in 13- to 18-yr-olds is most commonly caused by anovulation due to immature or dysregulation of hypothalamic-pituitary-ovarian axis as a function of normal physiology. This also can be when coagulopathy disorders are first identified.^1,3
• AUB in 19- to 39-yr-olds is most commonly due to pregnancy or structural issues such as polyps or fibroids, and cancer is relatively rare in this age range.^1,3
• AUB in 40-yr-old and older commonly is due to ovulation changes with perimenopause, but cancer has increased incidence in this age range.^1,3

• History and physical examination
• Laboratory, pathology, and imaging studies

• Pregnancy test
• CBC
• Thyroid-stimulating hormone (TSH)
• Wet prep and cervical cultures (Chlamydia trachomatis and Neisseria gonorrhoeae) if indicated
• Pap smear if indicated
• Targeted screening for bleeding disorders if suspected
• Endometrial sampling by endometrial biopsy or hysteroscopic sampling for women >45 yr or <45 yr with indication such as history of unopposed estrogen (polycystic ovary syndrome, obesity), failed medical management, or persistent abnormal bleeding
• Iron studies if anemia is suspected

• Pelvic ultrasound. Transvaginal ultrasound provides better assessment than transabdominal and is preferred.
• Sonohysterography or hysteroscopy if ultrasound is not adequate or further evaluation of the cavity is required, especially to assess for intracavitary lesions; superior to ultrasonography in detection of intracavitary lesions.
• MRI if needed for surgical planning or further evaluation of structural abnormality.

First-line therapy for acute AUB without known bleeding disorders is hormonal management, such as oral progestins, high-dose combined oral contraceptive pills, IV estrogen, tranexamic acid. Blood transfusion as indicated. Surgical management includes dilation and curettage, endometrial ablation (Fig. E1), uterine artery embolization, or hysterectomy (Table 1).^1-4 A comparison of effective reduction of blood loss with each treatment modality is summarized in Table 2.

• Combined hormonal contraceptives (pill, transdermal patch, vaginal ring) in a cyclic or continuous regimen
• Progesterone intrauterine device
• Oral progesterone
• Gonadotropin-releasing hormone analogue
• Elagolix (GnRH agonist) was FDA approved in 2020 for heavy premenstrual bleeding associated with uterine fibroids. Currently it is not recommended for use >24 mo due to concern for bone density loss
• Nonsteroidal antiinflammatory drugs
• Tranexamic acid

• Need for surgical intervention depends on stability of patient, bleeding severity, contraindication to medical management, or lack of response to medical management
• Dilation and curettage
• Hysteroscopic resection of uterine pathology including endometrial polyps and submucosal leiomyoma
• Myomectomy
• Endometrial ablation
• Uterine artery embolization
• Hysterectomy

• Refer to gynecologist if:
  1. Unresponsive to initial hormonal management
  2. Concern for a structural etiology or malignancy
  3. Endometrial sampling reveals endometrial hyperplasia or malignancy. Resampling is necessary with progestin therapy for hyperplasia. If endometrial hyperplasia associated with complex glands or atypia, consultation with gynecologist is warranted due to high degree of progression to malignancy

Heavy Menstrual Bleeding (Menorrhagia) (Patient Information)

Abnormal Uterine Bleeding (Related Key Topic)