Abnormal Vaginal Bleeding

The International Federation of Gynaecology and Obstetrics (FIGO) divides AUB in women of reproductive age into structural and non-structural causes using the PALM-COEIN classification system.15 Structural causes (PALM) include polyps, adenomyosis, leiomyomas (fibroids), and malignancy whereas non-structural causes (COEIN) include coagulopathy, ovulatory dysfunction, endometrial, iatrogenic and not otherwise classified.15 It is important to note that the cause of the bleeding may be multi factorial and several causes may coexist.14

  • Structural causes for AUB
    • Polyps
      • Localized tumours of the endocervix or endometrium4
      • Usually benign but some have atypical or malignant features15
      • Often asymptomatic can contribute to AUB15
    • Adenomyosis
      • Invasion of the myometrium by endometrial tissue4
    • Leiomyoma (fibroid)
      • Benign fibromuscular tumours of the uterus
      • Oten asymptomatic but can contribute to AUB4,15
    • Malignancy and hyperplasia
      • Serious but relatively uncommon cause of AUB15
  • Non-structural causes for AUB
    • Coagulopathy
      • 13% of those with HMB may have von Willebrand’s Disease18
      • Other patients may have single factor deficiencies or platelet disorders17
    • Ovarian dysfunction
      • Often no known cause but polycystic ovarian syndrome, hypothyroidism, hyperprolactinaemia, stress, obesity, weight loss, anorexia or extreme exercise can all affect ovarian function15
    • Endometrial
      • Primary disorder of local endometrial haemostasis15
    • Iatrogenic
      • A number of drugs and devices can cause or alter uterine bleeding, including:
        • Intrauterine devices – particularly in the first 6 months15
        • Breakthrough bleeding on oral contraceptives15
        • Tricyclic antidepressants15
        • Antipsychotics4
        • Anticonvulsants4
        • Anticoagulants15
    • Not yet classified

While the PALM-COEIN system sets out the causes for AUB in women of reproductive age, remember that not all vaginal bleeding is uterine in origin and not all patients are in this age cohort.

Non-uterine causes of vaginal bleeding include:

  • Ovarian bleeding
    • More commonly presents with intraperitoneal bleeding but may occasionally present with vaginal bleeding. Causes include cancer, torsion, ruptured cyst.19
  • Foreign body6,13,17,20
    • E.g. retained tampon, condom
  • Trauma of the lower genital tract21,22
    • Vulva, vagina or cervix
    • Blunt or penetrating trauma
    • May relate to a sexual assault or rape but may have another explanation such as an accidental injury
  • Gynaecological infections
    • Pelvic inflammatory disease (PID) is an ascending pelvic infection. It may cause tubo-ovarian abscess, salpingitis or endometritis22 and can present with bleeding.
  • Bleeding that is mistakenly reported to be vaginal bleeding e.g. rectal bleeding or haematuria23


Age cohort Potential causes of vaginal bleeding
Neonates Withdrawal from maternal oestrogen after delivery
Premenarchal Girls
  • Vaginitis
  • Foreign body
  • Trauma – sexual abuse should be considered but most vaginal trauma in this age group is an accidental injury
  • HMB caused by immaturity of the hypothalamic-pituitary-ovarian axis
  • Bleeding disorders may become apparent at this age if not diagnosed previously
  • Trauma including sexual assault
  • Sexually transmitted infections
Perimenopausal women

HMB caused by anovulatory cycles which become more common in this cohort

Postmenopausal women
  • Endometrial atrophy is the most common cause
  • Malignancy
    • All PMB should be considered a symptom of malignancy until proven otherwise

Learning bite

  • Vaginal bleeding can be uterine, or from elsewhere in the genital tract
  • Uterine bleeding has structural and non-structural causes
  • Differential diagnosis changes depending on the age cohort