Aetiology

The following causes should be considered in assessment of intermenstrual bleeding:

• hormonal imbalance
  • during perimnopausal period
    • however bleeding in this group should be investigated since it can be a symptom of underlying endometrial cancer
  • as a result of progesterone-only or low-dose oestrogen contraceptive pills
    • underdosing with the combined contraceptive pill causing breakthrough bleeding. Causes include:
      • too low a prescription
      • concurrent antiepileptic treatment
      • diarrhoea
  • contraceptive injection e.g. depoprovera
  • intrauterine contraceptive device
  • anovulatory uterine bleeding
    
    
• non hormonal
  • an ectropion which bleeds spontaneously or after intercourse
  • cervical polyps or cancer
  • fibroids
    • submucosal or pedunculated fibroids lead to irregular or heavy bleeding
  • endometrial polyps or cancer
  • inflammatory endometrial response to a copper intrauterine device
    • a malpositioned device (low lying or abnormally rotated in the uterine cavity) has a higher risk of irregular bleeding and pain
  • infection
    • endometritis caused by Chlamydia
    • gonorrhoea - less prevalent than Chlamydia
  • drugs which alter clotting parameters
    • antipsychotics, corticosteroids and anticoagulants
  • pregnancy related e.g. – ectopic pregnancy (1,2)

Reference:

• (1) Lumsden MA, Gebbie A, Holland C. Managing unscheduled bleeding in non-pregnant premenopausal women. BMJ. 2013;346:f3251.
• (2) Phadnis SV, Walker PG. Modern management of postcoital and intermenstrual bleeding. Trends in Urology Gynaecology & Sexual Health 2008;13(4)