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Lab test update - FSH (Menopause)

NEW SERIES Each week a consultant in laboratory medicine will take one lab test and answer questions about how to interpret it using a case study. The series kicks off with FSH, discussed by chemical pathologist Dr Stuart Smellie

NEW SERIES Each week a consultant in laboratory medicine will take one lab test and answer questions about how to interpret it using a case study. The series kicks off with FSH, discussed by chemical pathologist Dr Stuart Smellie

The case

A 48-year-old lady attends the surgery. She has no relevant past medical history, but for the last six months has felt tense, tearful and out of sorts.

Over the same length of time, her menstrual cycle has been lengthening and erratic, with her periods coming every six to eight weeks. She is on no prescribed medication but has been taking St John's wort.

Further inquiry reveals some significant stresses in her life, but she's sceptical that these are relevant to her symptoms. ‘I'm sure it must be the change, doctor,' she says. ‘So I'd like you to do some hormone tests.'

Is measurement of FSH useful in this type of situation?

I don't think it is. Menopause is a clinical diagnosis and also a normal physiological process. In the same way as puberty, testing is not needed unless the symptoms, signs or age of onset are unusual.

Provided she doesn't have symptoms, such as features of hyperthyroidism, other illness or a family history of thyroid disease, it would be perfectly reasonable to agree with her that her own diagnosis is very likely to be right, that time will tell, and to tell her that testing is not of any real benefit and won't change what you do.

If she is concerned, try directing her to a web resource or reading material for more information and reassurance.
I would also point out to her that any contraceptive decisions must not be based on laboratory measurements. She should continue her contraception for another two years after her periods have stopped. If she were over 50 we would say one year.

The only thing I might consider is opportunistic thyroid screening as the British Thyroid Association/Association of Clinical Biochemistry and British Thyroid Association guideline in 2006 suggested this group of women might merit screening.

What about the use of these tests in women under 40 to diagnose a premature menopause?

This is the main group where testing may be useful as it may be important to identify early menopause or premature ovarian failure. This would be even more important if she were coming to see you because of failure to conceive rather than menopausal symptoms. If so, there is a separate protocol – see by searching on ‘subfertility'.
If used to diagnose premature menopause, is a one-off test enough, or should it be repeated?

There is no absolute diagnostic threshold but:

• a single FSH value over 100IU/l is very likely to indicate established menopause in a patient with no periods
• two FSH samples over 30- 40IU/l, four to eight weeks apart, suggest ovarian failure
• LH and other sex hormones are of no benefit: persistently elevated FSH is the best and most reliable biochemical indicator of ovarian failure.


• FSH values fluctuate greatly both during the normal cycle and in the perimenopause
• lower FSH values do not exclude the perimenopause and the woman can still have potentially fertile cycles even if her FSH values are in the menopausal range.

How are FSH/LH levels influenced by OTC and prescribed treatments?

The most likely culprits are exogenous oestrogens, which are found in some herbal treatments. They can suppress FSH and LH, and also suppress or lengthen periods. Similarly, the main prescribed drugs that influence gonadotrophins are the sex steroids and drugs that influence them.

Drugs that can influence FSH results:

• Combined oral contraceptives

• High-dose progesterone-only preparations such as Depo-Provera

• HRT (including OTC preparations)

• Hormone antagonists such as tamoxifen

• Androgens including danazol and preparations containing dehydroepiandrosterone (DHEA)

What do ‘menopause home testing kits' measure, and how accurate and useful are they?

The same principles should apply to FSH home testing as to lab testing. I'm very unsure what the point is of a woman of menopausal age with typical symptoms spending money on these tests.

As I said earlier, values fluctuate so a test could be positive one week and negative the next. There's also a risk that someone who is home testing could decide to stop contraception because she thinks she can't become pregnant – no matter how exhaustively this is explained on the kits.

Two reviews of these tests in 2007 concluded that there was insufficient evidence to recommend using them.

Dr Stuart Smellie is consultant chemical pathologist for the County Durham and Darlington Acute Hospitals NHS Trust, and associate director of the specialist interests section of the Association for Clinical Biochemistry

Competing interests None declared

Lab test tubes Menopause testing Inappropriate tests

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