Blood testing in the menopause: what FSH and oestradiol tell you

Your ovaries respond less well to the signal from the pituitary gland. Fewer ovulations take place and oestrogen production becomes irregular. The pituitary compensates by raising its signal, which is why FSH moves upwards.

The years in which this happens are called the perimenopause. The menopause itself is your final period, and you can only establish that in hindsight: once your periods have been absent for twelve months. The menopause usually takes place between the ages of forty and sixty; the average age of the final period is around 51. About 1 in 100 women enters the menopause before the age of forty. For most women the complaints gradually ease in the years after the final period.

The complaints in this phase are erratic, precisely because your hormones do not fade gradually but first become unpredictable.

For almost every woman the menopause begins with changes in the cycle: periods become more irregular, shorter or longer, and the bleeding becomes lighter or heavier. In addition, Thuisarts.nl names these complaints:

• hot flushes and night sweats; about 8 in 10 women experience them to a greater or lesser degree
• sleeping badly, often because of the hot flushes and sweating
• mood swings, irritability or low mood
• vaginal dryness, itching or pain during sex; in about 3 in 10 women
• weight gain, joint and muscle pain
• forgetfulness or trouble concentrating
• more frequent bladder infections

None of these complaints is unique to the menopause: fatigue, poor sleep and mood complaints belong just as much to a thyroid problem, low iron stores, prolonged stress or sleep apnoea. That is exactly why the combination of your age, your cycle pattern and your complaints guides the doctor, rather than any single symptom.

In practice the menopause is established from your age, your complaints and the pattern of your cycle. A blood result supports that picture rather than settling it. Thuisarts.nl is clear about this: the GP establishes the menopause from your story, and for establishing the menopause itself a blood test is, in the words of Thuisarts.nl, of no use. The laboratory specialists of the NVKC put it this way: although women have higher FSH values after the menopause than before, this test cannot predict when a woman is in, or will enter, the menopause.

That is because of the fluctuations: during the perimenopause, cycles with and without ovulation alternate, and FSH and oestradiol move with them from week to week. A measurement taken today can look very different two weeks later. One result is therefore rarely the whole story.

What a blood test can do: support the picture once your periods have been absent for some time, bring another explanation for your complaints to light, and, with complaints at a young age, give your GP a starting point. Testing is therefore mainly valuable where there is doubt: with complaints below the age of forty, with a cycle that stops without a clear reason, or when your complaints could just as easily have another cause.

In this life stage these values mainly come up:

• FSH (follicle-stimulating hormone): the pituitary's signal to the ovaries. As the ovaries respond less, the pituitary signals harder and FSH moves upwards. It is the test most associated with the menopause, but also the one that fluctuates most.
• Oestradiol: the most important female sex hormone, made in the maturing follicles. It fluctuates strongly during the perimenopause and is clearly lower after the menopause; the body then still makes a small amount in fatty tissue.
• LH and progesterone: complete the cycle picture. Progesterone shows whether ovulation took place in that cycle.
• Prolactin: a raised prolactin can be another explanation for absent periods.
• TSH: the thyroid causes complaints that closely resemble the menopause and is therefore included as standard.

If you still menstruate, preferably have blood drawn on day 3 to 5 of your cycle, counted from the first day of your period. If you use hormonal contraception, always mention it: you are then mainly measuring the effect of the medication rather than your own cycle.

Many women search for the FSH value that belongs to the menopause, or for a normal oestradiol value. We deliberately do not quote those numbers.

A reference value is the range within which roughly 95 percent of healthy people fall; roughly 5 percent of healthy people therefore fall outside it without anything being wrong. For FSH and oestradiol there is something more: the laboratory uses separate reference values for each phase of the cycle and for the period after the menopause. The same result can be ordinary in one phase and striking in another. Without knowing which phase you were in on the day of the draw, a single number therefore says little, and that also applies to a number you read online.

Moreover, both hormones fluctuate so strongly during the perimenopause that a value which seems to fit the menopause today can be different again a month later. That is why your report shows the reference value of the performing laboratory next to your own value, with an explanation from our doctor that weighs your age, your cycle and any medication. The laboratory leads, the doctor weighs.

A number of conditions produce almost the same pattern of complaints and are readily measurable:

• an underactive or overactive thyroid
• anaemia or low iron stores with heavy periods
• a deficiency of vitamin B12 or vitamin D
• a raised blood sugar, which can cause fatigue and night-time urination
• prolonged overload, sleep apnoea or low mood

SchildklierNL, the Dutch thyroid patient organisation, points out that menopausal complaints sometimes resemble those of an overactive thyroid and sometimes those of an underactive one, which means a thyroid condition is easily missed in this life stage. If TSH is slightly raised, it is customary to wait and repeat the measurement after some time, because the value often recovers by itself. Read more about the thyroid and your blood.

If such a cause is found, something can be done about it. If nothing is found, you know that too, and it makes the conversation with your GP about your menopausal complaints more focused.

A hormone test on your own initiative fits these situations:

• Around the menopause: you want insight into the hormonal changes around the perimenopause, with the caveat that a single measurement is rarely decisive.
• Doubt about the cause: your complaints could just as easily come from the thyroid, your iron stores or a vitamin deficiency and you want to check that in one draw.
• General hormone status: you want to record a baseline to compare later measurements with.
• Cycle stopped without a clear reason: you want to know whether there is another explanation, such as a raised prolactin.

In these situations your GP is the first step, not a blood test on your own initiative:

• You have menopausal complaints and are younger than 40. An early menopause needs assessment and guidance from your GP or gynaecologist.
• You have bleeding after your periods have been absent for a year or longer, bleeding between periods, or bleeding so heavy that it leaves you tired or anaemic.
• You are considering hormone therapy for your complaints. That choice is made together with your GP on the basis of your complaints and your medical history.

You can bring a Bloodworks result into any of those conversations.

• 1Choose your test. The female hormone test measures FSH, oestradiol, LH, progesterone and prolactin in one draw. If fatigue and sleep are in the foreground, there is a test that checks the thyroid, your iron stores and vitamins B12 and D.
• 2Pay and complete the short intake. Our doctor assesses your request. Mention hormonal contraception, hormone therapy and other medicines, and on which day of your cycle you want to have blood drawn; this is taken into account in the assessment. After approval you receive your lab form digitally.
• 3Have your blood drawn. You choose one of the affiliated collection sites across the Netherlands; at most of them you can walk in without an appointment. Fasting is not needed for hormones; preferably attend in the morning and, if you still menstruate, on day 3 to 5 of your cycle.
• 4The laboratory analyses your blood. Your blood goes to a certified Dutch laboratory, which sets your values against its own reference range, per cycle phase.
• 5You receive your report with a doctor's interpretation. Your personal report is usually ready within two working days of the draw. A BIG-registered doctor explains your values in your context and advises on any next step. If a value deviates strongly, we contact you.

A raised FSH or a low oestradiol does not prove the menopause, and a result within the reference values does not rule it out. During the perimenopause both outcomes can alternate within weeks. Our doctor therefore looks at the whole: does the pattern of FSH, oestradiol, LH and progesterone fit your age, your cycle and your complaints, and is there another explanation that deserves attention first?

Situations in which the result is weighed differently, and which you should therefore mention in the intake:

• Hormonal contraception or hormone therapy: the pill, a hormonal coil or hormone therapy suppress or replace your own hormones; the result then mainly shows the medication.
• Cycle day: FSH and oestradiol differ per cycle phase; a draw on a day other than day 3 to 5 is set against a different reference range.
• Pregnancy or breastfeeding: change the hormone picture and raise prolactin.
• Medication: among others, some antidepressants, stomach acid inhibitors and blood pressure medicines can raise prolactin.
• Time of day: a draw in the morning gives the most stable picture.

If a value is abnormal, repeating it after a few weeks to months is often more useful than drawing a conclusion straight away, certainly with a slightly raised TSH; our doctor indicates in the report whether that is worthwhile. Hormone therapy or stopping contraception are never a decision based on this report alone; you take that decision together with your GP.

Once the menopause is behind you, the question changes. The loss of oestrogen is associated with a less favourable cholesterol profile and with bone loss in the longer term.

Valuable tests are then more likely to be a cholesterol profile, glucose and HbA1c, vitamin D and calcium, and thyroid function.