The vagaries of FSH as a "test" for menopause

QUESTION: I'm shocked because I went to the doctor and he did a blood test called FSH which showed I'm menopausal even though I'm having regular periods. How can this be?

ANSWER: Hormonal blood tests are notoriously unreliable as hormone levels vary widely from day to day and even during the day. The FSH test is basically useless for determining what stage of the perimenopausal transition anybody is in. Here are statements from the abstracts of three studies you can find on Medline. You might like to print out the whole abstracts and show them to your doctor if you want to convince him. Of course he *could* simply mean "perimenopausal" - the two words are often used interchangeably (and confusingly!) - Pat

http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=6790204&form=6&db=m&Dopt=b
Clin Endocrinol (Oxf) 1981 Mar;14(3):245-255
Pituitary-ovarian function in normal women during the menopausal transition.

It is concluded that the appearance of high levels of FSH and LH is characteristic of the perimenopause and often precedes the sustained loss of sex hormone secretion by the ageing ovary. Postmenopausal biochemical parameters are no guarantee of the postmenopausal state.

http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=8107620&form=6&db=m&Dopt=b
Maturitas 1993 Dec;18(1):9-20
Perimenopausal patterns of gonadotrophins, immunoreactive inhibin, oestradiol and progesterone.

It was concluded that typical postmenopausal hormone patterns may occur at the time of entry into the normal menopausal transition, and in some women with anovulatory infertility, but may be completely and relatively abruptly reversible. Elevation of serum FSH into the postmenopausal range, with undetectable INH concentrations, does not provide reliable evidence that the menopause (or permanent ovarian failure) has occurred. INH contributes to elevations of serum FSH during the menopausal transition.

http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=8124478&form=6&db=m&Dopt=b
Eur J Endocrinol 1994 Jan;130(1):38-42
Diagnostic role of follicle-stimulating hormone (FSH) measurements during the menopausal transition -- an analysis of FSH, oestradiol and inhibin.

It is concluded that FSH measurement is of little value, if any in the assessment of women during the menopausal transition because it cannot be interpreted reliably and because, apparently, ovulatory (and, presumably, potentially fertile) cycles may occur subsequent to the observation of postmenopausal FSH levels. Both oestradiol and inhibin are important negative feedback regulators of circulating FSH.

extract from Menopause 1999;6:29­35. © 1999, The North American Menopause Society
http://www.menopause.org/abstract/6129.htm

Among U.S. women aged 35­60 years, median FSH and LH levels began to increase for women in their late 40's and reached a plateau for women in their early 50's.This study supports the previously reported association between serum FSH and age (i.e., serum FSH and LH levels increase with age) and smoking (i.e., current smoking was associated with an increased level of serum FSH). At FSH levels of = or >15 IU/L or = or >20 IU/L, 70 and 73% of women, respectively, were postmenopausal. Our study also found an interaction between age and oophorectomy. In addition, the present data suggest that women with only one ovary may have higher FSH levels than women with both of their ovaries.

Full article: http://www.geocities.com/menobeyond/fsh.html

Category: FSH, menopause, perimenopause