What is the best blood marker for diagnosing menopause?

Follicle-Stimulating Hormone (FSH) is the Best Blood Marker for Diagnosing Menopause

The monotropic rise in FSH is the hallmark of the menopausal transition, making FSH the most important blood marker for diagnosing menopause. 1

Diagnostic Blood Markers for Menopause

Primary Marker: FSH

• FSH levels rise significantly during the menopausal transition due to decreased ovarian function
• Should be measured alongside estradiol for confirmation
• Most established and clinically validated marker for diagnosing menopause

Important Limitations of FSH Testing

• FSH is not a reliable marker in women with:
  • Prior chemotherapy exposure
  • Pelvic radiation exposure
  • Current tamoxifen use 1
  • Fluctuations may occur during perimenopause

Secondary Markers

Estradiol

• Low levels (<20 pg/mL) support menopausal diagnosis
• Should be measured concurrently with FSH
• For perimenopausal women with amenorrhea who later develop bleeding, serial estradiol measurements can help determine return of ovarian function 1

Anti-Müllerian Hormone (AMH)

• Produced by granulosa cells in preantral and small antral follicles
• Decreases with age and becomes undetectable several years before menopause
• May provide additional information on ovarian status but is not part of the clinical criteria for diagnosing menopause 1
• Better at predicting time to menopause than diagnosing current menopausal status 2, 3
• Not recommended for routine testing to predict time to menopause 3

Luteinizing Hormone (LH)

• Rises during menopause but less specific than FSH
• Can be measured alongside FSH but adds limited additional diagnostic value

Diagnostic Approach

1. Measure FSH and estradiol:

   • Postmenopausal range: FSH >40 IU/L and estradiol <20 pg/mL
   • Timing: If oligomenorrheic, measure during early follicular phase (days 2-5)
   • If amenorrheic, random measurement is acceptable 1

2. Consider clinical criteria:

   • Age ≥60 years
   • Age <60 years with amenorrhea for ≥12 months (in absence of chemotherapy, tamoxifen, or ovarian suppression)
   • Prior bilateral oophorectomy 1

3. For uncertain cases:

   • Serial measurements of FSH and estradiol
   • Consider AMH as supplementary information, not as primary diagnostic tool

Special Considerations

Cancer Survivors

• FSH is unreliable in cancer survivors with prior chemotherapy or pelvic radiation
• AMH may provide additional information but alone is not reliable 1
• Serial estradiol measurements may be more useful in this population

Women on Hormone Therapy

• Discontinue hormone therapy for at least 2 months before testing if possible
• Cannot determine menopausal status in women on LHRH agonists/antagonists 1

Young Women (<40 years)

• For suspected premature ovarian insufficiency, FSH remains the primary diagnostic marker
• AMH may help assess ovarian reserve but not diagnose menopause 1

Common Pitfalls to Avoid

• Relying solely on age or symptoms without laboratory confirmation
• Using AMH as the primary diagnostic marker for current menopausal status
• Measuring FSH only once (values can fluctuate during perimenopause)
• Interpreting FSH in isolation without estradiol levels
• Failing to consider medication effects on hormone levels

While AMH shows promise as a predictor of future menopause and ovarian reserve, FSH remains the most established and clinically validated blood marker for diagnosing current menopausal status.