What blood tests are used to check for menopause?

Blood Tests for Diagnosing Menopause

The diagnosis of menopause should be based primarily on clinical criteria (12 months of amenorrhea) with FSH testing as supportive evidence, not as the sole diagnostic criterion. 1

Diagnostic Blood Tests for Menopause

Primary Test:

• Follicle Stimulating Hormone (FSH)
  • FSH levels > 40 IU/L suggest postmenopausal status 1
  • However, FSH alone is not an effective predictor of transition into perimenopause or postmenopause 2
  • Single FSH measurements can be misleading as levels may fluctuate significantly during perimenopause 3

Supporting Tests:

• Estradiol
  • Levels < 30 pg/mL are consistent with menopause 1
  • Estradiol levels decline with age, particularly after approximately 38 years 4

Limitations of Blood Testing

• FSH levels show considerable overlap between premenopausal, perimenopausal, and postmenopausal states 2
• During perimenopause, FSH levels can fluctuate dramatically, rising into postmenopausal range and falling back to premenopausal range 3
• The commonly used FSH cutoff of 40 IU/L is not reliable by itself for determining postmenopausal status 2
• A single elevated FSH measurement is insufficient; approximately 40% of women with one high FSH reading will have normal levels in subsequent testing 5

Recommended Approach

1. Primary Diagnostic Criteria:

   • Age ≥ 60 years, or
   • Amenorrhea for ≥ 12 consecutive months 1

2. Laboratory Testing:

   • FSH > 40 IU/L
   • Estradiol < 30 pg/mL 1
   • If testing during perimenopause, consider multiple FSH measurements as a single test may be misleading 5, 3

3. Rule Out Other Conditions:

   • Thyroid disease
   • Diabetes
   • Other conditions that may mimic menopausal symptoms 1

Special Considerations

• For women using hormonal contraception (especially depot medroxyprogesterone acetate), FSH measurements may be unreliable 5
• For women over 50 years using hormonal contraception, at least two consecutive high FSH evaluations are recommended before confirming menopause 5
• Ovulatory cycles can still occur even after FSH levels reach postmenopausal range, so women should be counseled about possible continued fertility during perimenopause 1

Clinical Pearls

• Clinicians should diagnose perimenopause based primarily on menstrual history and age, without relying solely on laboratory testing 6
• There is a significant negative correlation between serum immunoreactive inhibin and FSH levels, suggesting inhibin's role in FSH regulation during the menopausal transition 4
• FSH levels typically begin to increase significantly after approximately 43 years of age 4