Treatments for Abnormal Uterine Bleeding (AUB) - Detailed Explanation

First, the Basics: How Estrogen and Progesterone Work (MOA)

• Estrogen (E) is the first worker. It builds up the uterine lining and also puts up "P receptors" (doors) on the endometrium so that progesterone can enter and do its job later.
• Progesterone (P) is the second worker. It can only act if estrogen has already prepared the lining (estrogen-primed endometrium). Once progesterone enters through those doors, it removes the estrogen receptors (locks out estrogen), stopping further buildup.

How We Decide Which Drug to Use (Decision Flowchart)

CASE 1: Thick Endometrium (Too much buildup)

Option A: OCP (Oral Contraceptive Pill - Combined E+P Pill)

• Contains both estrogen and progesterone.
• Works by stabilizing the lining and stopping further growth.
• Estrogen provides a stable base; progesterone then sheds it in a controlled way.
• Easy to take, good compliance, widely used.

Option B: Progesterone Only (P only pill)

• Since the lining already has enough estrogen and plenty of P receptors, giving progesterone alone is enough.
• Progesterone stabilizes the lining, reduces shedding, and stops the bleeding.
• Simpler than OCP, preferred when you don't want to add more estrogen.

CASE 2: Thin Endometrium OR Prolonged/Severe Bleeding

Option A: Estrogen first, then Progesterone (E f/b P)

• Give estrogen first to:
  1. Thicken the fragile lining (stop the bleeding by building it up)
  2. Create progesterone receptors ("doors")
• Then give progesterone to stabilize and support the lining.
• Think of it like: first you build the house (estrogen), then you furnish it (progesterone).
• This is used when the lining is too thin to sustain progesterone action alone.

Option B: Combined E+P OCP (Estrogen + Progesterone Oral Contraceptive Pill)

• Both hormones given together.
• The estrogen component repairs the thinned lining while the progesterone component stabilizes it simultaneously.
• Convenient as a single pill.

Progesterone in Detail

MOA (How it works):

1. Supports the endometrium - prevents it from shedding randomly.
2. Downregulates estrogen receptors when given continuously - this leads to endometrial atrophy (the lining becomes thin and inactive). This is actually the desired goal in AUB treatment.

• Reduced blood loss
• Amenorrhea (periods stop completely)
• Protection against endometrial cancer (no overgrowth from unopposed estrogen)

How to Give Progesterone (Supplementation Methods):

Method 1: Oral Progesterone - Given Continuously (3-6 months, no break)

• What it does: When given every single day without stopping, progesterone keeps downregulating estrogen receptors until the lining becomes atrophic (thin and inactive).
• Result: Endometrial atrophy = reduced or no bleeding.
• This is the PREFERRED mode of treatment in AUB.
• Why preferred? Because it directly causes atrophy, which is exactly what we want - a stable, non-bleeding lining.

Method 2: Oral Progesterone - Given Cyclically (Day 14 to Day 25 of the cycle)

• Given only during the second half of the cycle (days 14-25), mimicking the natural luteal phase.
• What it does: Supports the endometrium during this window and allows a controlled, predictable shedding (period) afterward.
• Used specifically in anovulatory DUB (when the patient doesn't ovulate and the cycle is irregular).
• Less preferred because:
  • Compliance is poorer (harder to remember a specific window of days)
  • Gives no contraceptive benefit (does not prevent pregnancy)
  • Does not produce atrophy, so bleeding control is less complete.

Method 3: Mirena (Progesterone-releasing IUCD)

• A small T-shaped device placed inside the uterus that releases progesterone locally, directly into the uterine lining.
• What it does: Causes local endometrial atrophy (same mechanism as continuous oral progesterone, but right at the site of action).
• Key points:
  • Provides relief of AUB in 30-40% of cases
  • Acts locally, so very few systemic side effects
  • Also provides contraception
  • Preferred for women who want long-term AUB management without taking daily pills

Who Gets Which Treatment? (Preferred Indications)

• Reproductive age females with AUB
• Perimenopausal females (approaching menopause) - especially to protect the endometrium from estrogen-driven overgrowth

• Good compliance (easy daily pill)
• Reduces the need for hysterectomy
• Minimum 12 days per month of progesterone is needed to get the protective/anti-proliferative effect on the endometrium

Specific Management Based on Cause

Structural Lesion (e.g., fibroid, polyp, cancer)

• Treat the cause directly (surgery, removal of polyp, etc.)
• Hormonal drugs alone won't fix a structural problem.

Non-Structural Lesion (hormonal cause)

• Give oral iron (to replenish iron lost from blood loss)
• Continue maintenance drugs (the hormones that controlled the bleeding)

• Blood transfusion if hemoglobin is critically low
• Switch to 2nd line medical management (stronger or different drugs)

Indication for Blood Transfusion

• In young girls with heavy menstrual bleeding at puberty, if their hemoglobin drops below 7 g/dL, they need a blood transfusion to stabilize them first, before hormone treatment can take effect.

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