Abnormal Uterine Bleeding

Abnormal uterine bleeding is an umbrella term used to describe a variety of irregularities in uterine bleeding. Though generally not life-threatening, abnormal uterine bleeding is frequently "life-altering" in terms of psychosocial and economic well-being. A single menstrual cycle, commonly referred to as "a period," begins with the onsest of menses and ends the day before the next menses. Most cycles fall within a range of 24-38 days. An individual's cycle lengths can vary by several days from cycle to cycle. Mean cycle length overall is 29 days. Bleeding duration is 4 days (plus or minus 1.5 days). Blood loss ranges widely, from 5-80 milliliters. Abnormal uterine bleeding (AUB): Irregularities in frequency, regularity, duration, or volume of menstrual bleeding outside of pregnancy – essentially, irregularities in any of the parameters we noted above. Includes Heavy Menstrual Bleeding and Intermenstrual Bleeding (formerly called "menorrhagia" and "metrorrhagia," respectively). "Acute abnormal uterine bleeding" is excessive bleeding and requires immediate intervention to prevent further blood loss. Abnormal uterine bleeding is chronic when irregularities persist for 6 months or longer. Physiological vs Pathological: Abnormal uterine bleeding is quite common, particularly in the months after menarche (the onset of menstrual cycles in puberty) and before menopause (perimenopause). Irregular bleeding patterns may or may not reflect underlying pathologies; for example, abnormal uterine bleeding is an important sign of uterine cancer, but it is also common in athletes when strenuous training regiments divert energy from reproductive functions to musculoskeletal maintenance. Treatments: Vary by etiology, severity of symptoms, and patient fertility desires – for example, some patients with painful, irregular bleeding patterns may opt for surgeries that impair fertility, while others who wish to become pregnant do not. Complications: Depend on the etiology and severity; can include anemia (particularly with heavy menstrual bleeding), infertility, and endometrial cancer. PALM refers to structural etiologies of irregular menstrual bleeding. COEIN refers to the non-structural etiologies of irregular menstrual bleeding. Be aware that a patient can have multiple conditions simultaneously. From outer to inner layers: the serosa, myometrium, and endometrium. Because the PALM etiologies are structural, we can diagnose them with imaging, usually transvaginal ultrasound, and histopathology. Polyps: Abnormal growths of glands and mucosa surrounding a vascular core; they can be pedunculated (as shown in our illustration) or sessile (flat). Polyp size ranges from small, approximately 5 millimeters in diameter, to quite large, filling the uterine cavity. Polyps are very common, and usually benign, but can cause infertility. The most common sign of endometrial polyps is abnormal uterine bleeding. Polyps may regress on their own, but surgical removal is often recommended in postmenopausal and symptomatic premenopausal patients, who have elevated cancer risks. Adenomyosis: Characterized by endometrial glands and stroma that grow in the myometrium and induce myometrial hypertrophy. Dysmenorrhea (painful menstruation) and heavy menstrual bleeding are the most common presentations; be aware that adenomas often co-exist with leiomyomas and endometriosis. Treatment includes NSAIDs for pain management and hormone therapies (oral contraceptives, intra-uterine devices, aromatase inhibitors), and a range of surgical interventions (endometrial ablation, myomectomy, hysterectomy). Leiomyomas, aka, fibroids: Common, benign neoplasms that arise from smooth muscle uterine cells. Their growth is dependent on estrogen and progesterone. Risk factors include excessive exposure to estrogens (i.e., early menarche, late menopause, nulliparity, obesity). Can be asymptomatic, or may present with abnormal uterine bleeding, pelvic and back pain; complications include infertility and spontaneous abortion. Treatments include NSAIDs, hormonal therapies, surgical interventions (similar to adenomyosis). Malignancy and hyperplasia: Hyperplasia is associated with an imbalance in estrogen and progesterone levels, with elevated estrogen promoting disordered endometrial gland proliferation. We see this in poly-cystic ovarian syndrome, estrogen-secreting tumors, hormone replacement therapy, and tamoxifen (which is used in breast cancer treatments). Most uterine malignancies are endometrial cancer; under the influence of excessive estrogen, hyperplasia progresses to dysplasia and then carcinoma. Coagulopathy: Systemic disorders of hemostasis, usually von Willebrand Disease, accounts for approximately 13% of patients with heavy menstrual bleeding. Ovulatory disorders: Characterized by anovulation or irregular ovulation, can cause AUB. Examples include poly-cystic ovarian syndrome, hypothyroidism, and psychological, nutritional, and physical stressors. Endometrial causes: Suspected when menstrual cycles are otherwise predictable. For example, disordered endometrial hemostasis can cause heavy menstrual bleeding (disordered endometrial hemostasis might arise from deficient production of local vasoconstrictors, accelerated clot lysis, or excessive vasodilation); Endometrial inflammation and infection (i.e., endometritis) can also cause irregular menstrual bleeding. Iatrogenic Warfarin and other anti-coagulants as well as drugs/devices that interfere with ovulation – we show an intrauterine device in our diagram. The original classification system placed these in coagulopathy and ovulatory disorders, respectively. "Not otherwise classified": Includes arteriovenous malformations and other phenomena that are not already classified. Formerly called "not yet classified."