CLINICAL ACTIONS:

Abnormal uterine bleeding in the setting of anovulation or oligoovulation (AUB-O) results from chronic estrogen stimulation of the endometrium. In the setting of irregular, prolonged bleeding (menorrhagia)

• Perform an age appropriate history and physical exam
• Appropriate lab tests include
  • Pregnancy test
  • Thyroid function tests
  • Prolactin level
  • PT/aPTT
  • Sexually transmitted disease testing
  • Complete blood count if bleeding is prolonged and heavy
• Endometrial biopsy should be performed in women over age 45 or those of any age with risk factors for endometrial hyperplasia or malignancy
  • Nulliparity, hypertension, obesity, irregular menses and family history of endometrial cancer
• Saline infusion sonohysterography (SIS), hysteroscopy or transvaginal ultrasound may be used to rule out an anatomic abnormality
• ACOG states that

Failure of medical management requires further investigation, including imaging or hysteroscopy

SYNOPSIS:

Ovulatory menstrual cycles generally occur between 21 and 45 days, are predictable, and last about 5 days reflecting sequential stimulation of the endometrium first by estrogen alone, then by a combination of estrogen and progesterone and finally by withdrawal of both hormones. The cause of AUB-O can be an abnormality at any level of the hypothalamic-pituitary-ovarian axis.  Consequences can include blood loss anemia due to heavy bleeding, as well as endometrial hyperplasia and endometrial cancer.

FIGO Subclassification System

The 4 types can be referred to by the acronym ‘HyPO-P’ | Last ‘P’ separated because it does not track to a single anatomic location

• Type 1: Hypothalamic
  • Genetic
  • Autoimmune
  • Iatrogenic
  • Neoplasm
• Type II: Pituitary
  • Functional
  • Infectious/Inflammatory
  • Trauma & Vascular
• Type III: Ovarian
  • Physiologic
  • Idiopathic
  • Endocrine
• Type IV: PCOS
  • Diagnosis and categorization and recommended by the International PCOS network

Note: According to FIGO, “The new system provides practical utility and a second layer, or sub-classification, for each of the three anatomically defined entities, including discrete pathophysiological categories. These can be remembered using the acronym ‘GAIN-FIT-PIE'”

KEY POINTS:

• The levonorgestrel IUD is effective in treating AUB-O and can be offered to all age groups
• Progestin and combination birth control pills are common medical options
• Weight loss and exercise should be strongly recommended for overweight anovulatory women
• Surgical therapy, such as hysterectomy, is rarely indicated but can be considered in women who have failed medical therapy or in whom medical therapy is contraindicated
• Hysterectomy with removal of the cervix can be offered to women who meet above criteria and have completed childbearing, or who have significant intracavitary pathology
• Endometrial ablation is not recommended as a first line therapy for AUB-O as traditional methods of endometrial surveillance may not be possible after the procedure
• ICD 10 code: N93.9

Learn More – Primary Sources:

ACOG Practice Bulletin 136: Management of Abnormal Uterine Bleeding Associated with Ovulatory Dysfunction

AAFP: Review of ACOG Practice Bulletin No. 136

FIGO: Ovulatory Disorders Classification System

Evaluation of Amenorrhea, Anovulation, and Abnormal Bleeding

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