Abnormal Uterine Bleeding (AUB)

Overview

• Abnormal uterine bleeding (AUB) is defined as any significant deviation from normal menstrual bleeding in terms of frequency, regularity, heaviness, and duration.
• It encompasses various conditions, including heavy menstrual bleeding (HMB).
• AUB is a common issue, requiring referral to gynecologists for investigation and treatment.
• Hysterectomy, previously a frequent treatment for HMB in women under 60, is now less common due to improved treatment options.

Physiology of Normal Menstruation

• Normal menstruation involves controlled release of hormones (FSH, LH, estradiol, progesterone) from hypothalamus and pituitary gland.
• The cycle has predictable duration and amount of bleeding.
• Characteristics of normal menstruation: Average cycle length 28 days ± 7 days (24 to 35 days); Average duration 4-7 days (average 6 days); Average blood loss <80 ml (average 30 ml).
• Factors affect normal menstruation: Individual differences; Cycle-to-cycle variation.

Demography

• A large percentage of women seek treatment for heavy menstrual bleeding (HMB), making it a significant concern.
• HMB is a relatively common issue and is one of the top 4 reasons for referral to a gynecologist.
• Treatment for HMB, in previous years, was predominantly hysterectomy, but this practice has been declining with the development and availability of other treatments.

Documentation

• Important to precisely document menstrual periods.
• Using a menstrual cycle record can improve the correlation between patient complaints and measured blood loss.
• Measurement of menstrual blood loss (MBL) is cumbersome and there are simpler methods to estimate/qualify it.
• Mobile apps or pictorial charts may offer more convenient ways to track and document MBL.

Defining Events

• Menstruation is complex and involves both endometrial and vascular processes.
• It is a combination of enzymatic degradation and even hypoxia.

Pathology

• Abnormal uterine bleeding (AUB) encompasses any deviation from regular menstrual cycles.
• This can include variations in the frequency, regularity, heaviness, or duration of flow.
• Heavy Menstrual Bleeding (HMB) is a significant concern.
• AUB can be categorized as primary (occurring secondary to other conditions).
• Some AUB causes are Structural (e.g., polyps, fibroids, adenomyosis, malignancy) and Non-Structural (e.g., ovulatory issues, coagulopathy).

FIGO Classification

• FIGO (International Federation of Gynecology and Obstetrics) classifies AUB into categories based on the underlying cause.
• The PALM-COEIN system categorizes AUB based on structural (PALM) or non-structural (COEIN) factors.

Proper Diagnosis

• Thorough history taking, clinical exam, and appropriate investigations (laboratory and imaging) are crucial to identifying the cause of AUB.
• Diagnoses focus on excluding other, more common causes before considering rare or less likely diagnoses.
• Determining whether the AUB is related to pregnancy or not.

Practice Updates

• Medical management is the first-line approach, especially if the patient desires to retain her uterus.
• Medical therapies target reducing bleeding and include hormone therapies (e.g., estrogen, progestin) and other medication such as NSAIDs and antifibrinolytics.
• Surgical options (e.g., endometrial ablation, hysterectomy) are considered when medical management fails or is unsuitable.

Review Questions

• Review questions are provided to test understanding of the various aspects of AUB such as frequency, duration, volume, causes, and diagnostics.

This lesson covers abnormal uterine bleeding (AUB), including heavy menstrual bleeding (HMB), its prevalence, and the shift away from hysterectomy as a primary treatment. It also explains the physiology of normal menstruation, including hormonal control and cycle characteristics.