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Hormone Test

Estradiol Test

A detailed guide to the Estradiol (E2) test, explaining its vital role in developing eggs, regulating the menstrual cycle, and preparing the uterus for pregnancy.

Test Overview

Estradiol (E2) is produced by the ovaries. It signals the uterus to thicken its lining and, when it peaks, triggers the ovulation surge.

Key Timing

For fertility baselines, the test is preferably done on Day 3 of the menstrual cycle (Day 2-4 is acceptable), usually alongside FSH.

1. Purpose and Uses of the E2 Test

The Estradiol test checks the functioning of the ovaries and the overall reproductive system.

For Women

  • Evaluate ovarian reserve (with FSH).
  • Investigate irregular or absent periods.
  • Monitor follicle development during IVF stimulation.
  • Diagnose menopause symptoms.
  • Detect ovarian tumors or hormonal disorders.

For Men

  • Evaluate gynecomastia.
  • Check infertility causes / low sperm production.
  • Investigate delayed puberty.

2. Procedure and Timing

This is a standard blood test drawn from a vein in the arm. Estradiol levels change quickly, so timing is very important.

When to Test?

For baseline fertility checks, the standard is Day 3 of the menstrual cycle.

Medication Warning

Birth control pills, DHEA, and corticosteroids may alter E2 results. Doctors may advise stopping them temporarily before testing.

3. Role in Fertility

Estradiol is a key hormone that prepares the body for ovulation and pregnancy.

  • Follicular Phase: Produced by growing follicles.
  • Ovulation Trigger: Peak E2 causes an LH surge.
  • Uterine Lining: Supports implantation.
  • Pregnancy: Placenta takes over E2 production.

4. Normal Levels

Patient Group / PhaseRange (pg/mL)
Follicular Phase (Day 3 baseline)20 – 160
Ovulation Peak110 – 410
Post-Menopause< 20
Men10 – 60

5. Estradiol and IVF

  • Baseline: Should be under 60 pg/mL before stimulation.
  • During IVF: Each mature follicle produces ~200–300 pg/mL.
  • Monitoring: Used to determine trigger timing.

6. Interpreting Results

Low Estradiol

  • Menopause or perimenopause.
  • PCOS-related imbalance.
  • Low body fat / excessive exercise.
  • Turner Syndrome.

High Estradiol

  • Functional ovarian cysts.
  • Rare ovarian tumors.
  • Diminished ovarian reserve — high E2 can mask a high FSH level.

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