Description

• The term menorrhagia has fallen out of favor and the terminology “abnormal uterine bleeding” (AUB) is now preferred.
• AUB describes a range of symptoms, such as heavy menstrual bleeding (HMB), intermenstrual bleeding (IMB) and a combination of both heavy and prolonged menstrual bleeding (1).
• Due to inconsistent use of terminology and definitions to characterize AUB, the International Federation of Gynecology and Obstetrics (FIGO) has developed two systems to assist with the major challenge of determining the cause of AUB for clinicians. These include:
  • FIGO AUB system 1: standardized nomenclature and defined the parameters of normal and abnormal menstrual bleeding
  • FIGO AUB system 2: focused on classifications of AUB etiology into structural and nonstructural causes using the PALM-COEIN classification system (see below)

Epidemiology

• AUB is a common problem that leads to increased health care costs and decreased quality of life.
• It is one of the leading causes of outpatient gynecologic visits, with 20–30% of patients presenting with this complaint annually.

Prevalence

• AUB has a profound impact on women in their reproductive years and has a prevalence of 3–30%.
• The prevalence varies with age and is higher in adolescence and the fifth decade.

Etiology and Pathophysiology

• The pathophysiology of AUB is as diverse as the classification of the disease.
• Structural causes include (PALM acronym)
  • P—polyp (AUB-P)
  • A—adenomyosis (AUB-A)
  • L—leiomyoma (AUB-L)
    • Submucosal leiomyoma (AUB-LSM)
    • Other myoma (AUB-LO)
  • M—malignancy/hyperplasia (AUB-M)
• Nonstructural causes (COIEN acronym) include:
  • C—coagulopathy (AUB-C)
  • O—ovulatory (AUB-O)
  • E—endometrial (AUB-E)
  • I—iatrogenic (AUB-I)
  • N—not yet classified (AUB-N)

Genetics


Pediatric Considerations

• Genital bleeding before puberty is, by definition, not menstrual bleeding and requires further evaluation.
• Due to immaturity of the hypothalamic-pituitary-ovarian axis, adolescents are at risk of irregular bleeding and HMB.
• Adolescents with HMB should be evaluated for possible bleeding disorders, especially von Willebrand disease and qualitative platelet dysfunction.

Pregnancy Considerations
Bleeding in pregnancy is, by definition, not menstrual bleeding and requires further evaluation. Pregnancy test should be obtained as part of the evaluation of AUB.

General Prevention

• Combined oral contraceptives may prevent HMB, particularly when progesterone is dominant. Lower estrogen doses result in less menstrual bleeding.
• Progesterone-only contraceptives may reduce overall blood loss but often result in irregular bleeding.