Uterine Bleeding, Abnormal

Basics

Description

  • Formerly termed “dysfunctional uterine bleeding”
  • Abnormal uterine bleeding is an alteration in regularity, frequency, duration, or volume of normal menses:
    • Blood loss during normal menses is 30–80 mL
    • Normal interval between menses 28 (+/− 7) d
  • 2 classifications:
    • Abnormal uterine bleeding (AUB):
      • Hormonally related
      • Anovulatory and ovulatory categories
      • Not due to organic or iatrogenic causes
      • Diagnosis of exclusion
    • Organic uterine bleeding:
      • Bleeding related to systemic illness or disease of the reproductive tract

Etiology

  • Anovulatory (most common):
    • Unopposed estrogen stimulation of proliferative endometrium
    • Estrogen withdrawal bleeding
    • Alteration of neuroendocrine function due to:
      • Polycystic ovarian syndrome (PCOS)
      • Very–low-calorie diets, rapid weight change, intense exercise, anorexia nervosa
      • Psychological stress
      • Obesity
      • Medications including oral contraceptives
      • Drugs
      • Hypothyroidism
      • Primary hypothalamic dysfunction
  • Ovulatory:
    • Inadequate uterine PGF2α:
      • Increased uterine contractility
    • Excessive uterine prostacyclin:
      • Diminishes platelet function and increases uterine vasodilation
  • Bleeding disorders should be suspected if:
    • Family history
    • Menorrhagia since early age
    • Other bleeding or bruising

Pediatric Considerations
Anovulatory bleeding common in adolescence owing to immaturity of the hypothalamic–pituitary–ovarian axis

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