What laboratory tests are used to diagnose menopause?

Laboratory Tests for Diagnosing Menopause

Laboratory evaluation for diagnosing menopause should include estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin, as clinically indicated. 1

Definition of Menopause

Menopause is defined as the permanent cessation of menstruation resulting from the loss of ovarian follicular activity. Clinically, it is established by the absence of menstruation for 12 months or more.

Diagnostic Criteria

Several clinical and laboratory parameters help determine menopausal status:

Clinical Criteria:

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

Laboratory Tests:

1. Primary Laboratory Tests:

   • Follicle-stimulating hormone (FSH) - Elevated in menopause due to declining inhibin B levels
   • Estradiol - Decreased levels in menopause
   • Luteinizing hormone (LH) - Typically elevated in menopause
   • Prolactin - To rule out hyperprolactinemia as a cause of amenorrhea

2. Additional Tests in Specific Situations:

   • Anti-Müllerian hormone (AMH) - Provides information on ovarian reserve
   • Inhibin B - Reflects declining follicle numbers
   • Thyroid-stimulating hormone (TSH) - To rule out thyroid disease as a cause of symptoms

Important Considerations for Laboratory Testing

1. FSH Reliability Issues:

   • FSH is not a reliable marker of menopausal status in women with prior chemotherapy or pelvic radiation exposure 1
   • FSH is unreliable in women on tamoxifen 1
   • Single FSH measurements can be misleading as levels fluctuate significantly during perimenopause 2

2. Special Populations:

   • For women using hormonal contraceptives or hormone therapy, FSH and estradiol measurements may be affected
   • For women with therapy-induced amenorrhea, serial measurements of FSH and/or estradiol are needed 1
   • For DMPA (Depo-Provera) users over 40, at least two consecutive high FSH measurements are recommended to confirm menopause 3

3. Male Patients:

   • In male cancer survivors with suspected hypogonadism, morning total testosterone and free testosterone should be checked 1

Interpretation of Results

• Postmenopausal Range: FSH >35 mIU/mL is typically considered in the postmenopausal range 3
• Fluctuations: During perimenopause, hormone levels can vary markedly, making single measurements unreliable 4
• Serial Testing: For perimenopausal women who become amenorrheic and later develop bleeding, serial estradiol levels can help determine return of ovarian function 1

Limitations of Laboratory Testing

• An elevated serum FSH level alone cannot reliably determine when menopause has occurred 2
• Abrupt fluctuations in serum FSH and estradiol may occur during perimenopause, with levels returning to the normal reproductive range after being in the postmenopausal range 2
• The diagnosis of menopause is primarily clinical and should not rely solely on laboratory values 5

By following these laboratory testing guidelines while understanding their limitations, clinicians can more accurately assess menopausal status and provide appropriate management for symptoms that impact quality of life.