What are the causes of Abnormal Uterine Bleeding (AUB) related to menstrual disorders?

From the Guidelines

Abnormal Uterine Bleeding (AUB) related to menstrual disorders is primarily caused by structural and nonstructural etiologies.

Causes of AUB

• Structural causes include:
  • Endometrial polyps
  • Adenomyosis
  • Leiomyoma (uterine fibroids)
  • Malignancy (endometrial or myometrial)
  • Endometrial hyperplasia
• Nonstructural causes include:
  • Coagulopathies
  • Ovulatory dysfunction
  • Primary endometrial disorders
  • Iatrogenic etiologies (such as exogenous gonadal steroids and intrauterine devices) As noted in the study by 1, the workup of a woman with abnormal bleeding begins with a thorough history, physical examination, and appropriate laboratory tests and may include imaging to primarily assess for structural abnormalities. In premenopausal women, polyps, adenomyosis, and leiomyoma are the common structural sources of AUB 1. Uterine fibroids, also called leiomyomas or myomas, are the most common benign tumor in patients of reproductive age and can cause heavy and prolonged uterine bleeding 1. The diagnosis of uterine fibroids is made with pelvic ultrasound (US) or MRI, which further characterizes fibroid location, size, and number 1. Medical therapy with oral contraceptive medication or gonadotropin-releasing hormone (GnRH) agonists or antagonists can manage bleeding symptoms effectively, especially in women with small fibroids 1. Tranexamic acid is a nonhormonal agent that has been used previously for the treatment of dysfunctional uterine bleeding and may help reduce the menorrhagia associated with fibroids 1. Selective progesterone receptor modulators (SPRMs), such as ulipristal acetate (UPA), have shown promising results in the management of uterine fibroids and can reduce fibroid-related bleeding and improve quality of life 1.

From the Research

Causes of Abnormal Uterine Bleeding (AUB)

The causes of Abnormal Uterine Bleeding (AUB) can be categorized into structural and non-structural conditions.

• Structural causes include:
  • Polyp 2, 3, 4
  • Adenomyosis 2, 5, 3, 4
  • Leiomyoma (fibroids) 2, 5, 3, 4
  • Malignancy and hyperplasia 2, 3, 4
• Non-structural causes include:
  • Coagulopathy 2, 3, 4
  • Ovulatory dysfunction 2, 5, 3, 4
  • Endometrial causes 2, 3, 4
  • Iatrogenic causes 2, 3, 4
  • Not yet classified causes 3, 4
  • Extragenital disorders, such as diseases of the thyroid gland, uncorrected diabetes, obesity, blood coagulation disorders, infectious diseases, and certain drugs 6
  • Psychological stress, climate change, and diet 6

Classification of AUB

AUB can be classified using the PALM-COEIN system, which stands for:

• PALM: Polyp, Adenomyosis, Leiomyoma, Malignancy and hyperplasia
• COEIN: Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not yet classified 3, 4

Symptoms of AUB

AUB can manifest as:

• Heavy menstrual bleeding (HMB) 5, 3
• Irregular menstrual bleeding 5, 3
• Intermenstrual bleeding (IMB) 5, 3
• A combination of heavy and prolonged menstrual bleeding 3