Heavy Menstrual Bleeding, Improving Knowledge, Improving Lives
In some cases, the causes of Heavy Menstrual Bleeding are not classified

Not otherwise classified


  • This includes cases where abnormal uterine bleeding is not related to pregnancy, structural pelvic alterations, hormonal imbalance, hormonal contraception or chronic disease1,5
  • Conditions might include myometrial hypertrophy and arteriovenous malformations, or uterine ischiocele related to the uterine scar from a previous cesarean section2,3,4



  • Abnormal uterine bleeding in a woman in whom other causes were excluded



  • Exclude other potential causes of abnormal uterine bleeding: detailed patient history, gynecological examination, blood tests, transvaginal ultrasound1
  • Endometrial biopsy can identify a previously non diagnosed structural cause (i.e. endometrial polyps or hyperplasia)1



  • Medical treatment should be considered as a first-line option in the absence of structural abnormalities5,6
  • Non-hormonal treatments: NSAIDs (like mefenamic acid) and tranexamic acid5
  • Hormonal treatments: cyclical progestins, combined oral

Not otherwise classified HMB Library

Find more information and download materials on not otherwise classified HMB in the teaching and resources library.


  1. Grzechocinska B, et al. J Womens Health Issues Care 2017;6:1.
  2. Munro MG, et al. Int J Gynaecol Obstet 2018; 143,393–406.
  3. Munro MG, et al. BJOG 2017;124:185–9.
  4. Munro MG, et al. Int J Gynaecol Obstet 2011;113:3–13.
  5. Singh S, et al. J Obstet Gynaecol Can 2013;35(5_eSuppl):S1–S28.
  6. Bradley LD & Gueye NA. Am J Obstet Gynecol 2016;214:31–44.

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