FSH alone can't diagnose menopause

A single determination of follicle-stimulating hormone (FSH) is neither sufficiently sensitive nor specific to predict the final menstrual period, according to data from the National Health and Nutrition Examination Survey (NHANES 1999–2000).

Researchers looked at a nationally representative sample of 576 women between 35 and 60 years of age. They found that while levels of FSH and luteinizing hormone (LH) increased significantly with reproductive age, considerable overlap existed among FSH readings by reproductive stage, most likely reflecting the wide fluctuations in ovarian hormones and FSH and LH levels that occur with increasing menstrual irregularity.

As a result, a FSH cutoff of 13 mIU/mL has a sensitivity to determine whether a woman is in the reproductive versus menopause transition stage of only 67.4% (95% CI; 50.0–81.1) and a specificity of only 88.1% (95% CI; 81.1–92.8). Between the menopause transition and postmenopausal stages, a FSH cutoff of 45 mIU/mL has a sensitivity of 73.6% (95% CI; 60.1–83.7) and a specificity of 70.6% (95% CI; 52.4–84.0).

Dr. Santoro went on to say that detailed menstrual cycle data combined with some hormonal confirmation are the best determinant of reproductive status, and that "a running range of almost 2 months between menstrual periods is highly predictive of the final menstrual period within the next 18 months." For most women, amenorrhea of 3 to 11 months predicts menopause within 4 years.

Henrich JB, Hughes JP, Kaufman SC, et al. Limitations of follicle-stimulating hormone in assessing menopause status: findings from the National Health and Nutrition Examination Survey (NHANES 1999–2000). Menopause. 2006;13:171-177.

Santoro N. Doctor, can you order that menopause test? Menopause. 2006;13:158-159.