These posts often highlight troubling symptoms of perimenopause. Then they flag blood tests as a way to help you understand what’s going on and to guide treatment.

Some women are now turning to wellness providers and online services seeking these types of tests, often at substantial expense.

But these tests don’t provide any benefits. An editorial in the British medical journal BMJ has raised an alert about these tests. The authors conclude they’re unnecessary and shouldn’t guide treatment decisions.

So what hormonal changes occur in the transition to menopause? And why is hormonal testing mostly unhelpful?

What do hormones do during menstrual cycles?

The key hormones the ovaries produce before menopause are oestrogens (mostly as oestradiol, but also as oestrone) together with progesterone and testosterone.

The amount of each hormone produced changes during the menstrual cycle.

Blood oestradiol levels double around the time of ovulation. This is followed by an increase in progesterone.

Testosterone blood levels also increase around ovulation, but the increase is less than about 10%.

What’s the difference between menopause and perimenopause?

Menopause happens when the ovaries have lost the capacity to produce an egg.
After menopause, oestrogen and progesterone blood levels are dramatically lower than before menopause.

Perimenopause is the time between being pre-menopausal, through to the first 12 months after having the last menstrual bleed. But the end of perimenopause is difficult to determine if you don’t menstruate, for example after a hysterectomy or when you have a hormonal intra-uterine device (IUD).

Testosterone blood levels don’t meaningfully change at natural menopause; they slowly decline with age.

What are the symptoms of perimenopause?

During the transition to menopause, the ovaries function haphazardly. So oestrogen and progesterone blood levels can be unpredictably very high or very low.

Hot flushes and night sweats, also known as vasomotor symptoms, commonly start in early perimenopause and may persist for many years. Vasomotor symptoms occur intermittently during perimenopause and persist after menopause.

Perimenopause is identified by irregular periods (cycles closer together or further apart) or changed bleeding patterns (bleeding becoming scant or heavy), together with the onset of vasomotor and other symptoms such as:

• increased abdominal fat
• low mood
• vaginal irritation and dryness
• urinary symptoms, such as bladder irritability
• memory difficulties, or “brain fog”. This seems to relate to the fluctuations in oestrogen levels and mostly resolves in the early postmenopausal years.

Our recent study shows the onset of vasomotor symptoms is the hallmark of perimenopause, and should also be used to diagnose perimenopause in women not menstruating (after hysterectomy or for other reasons).

Can a blood test tell you’re perimenopausal?

Blood oestradiol and progesterone levels are continually fluctuating during perimenopause. A blood test cannot be “timed” to any specific part of the cycle, as cycles vary in length and frequency.

So the results can’t generally be interpreted and are therefore not helpful.

However, it’s sensible to have blood tests to check for common causes of fatigue (under-active thyroid or iron deficiency) and palpitations and overheating (over-active thyroid).

How is perimenopause managed?

Treating perimenopause is not the same as treatment after menopause. Perimenopause is a time of hormonal chaos, rather than deficiency. So standard menopause hormone therapy (also called MHT) can make things worse.

Adding in an extra layer of hormones with the MHT that’s used after menopause will ease symptoms during the hormone lows, but often worsens symptoms during hormone highs (heavy bleeding, breast tenderness, fluid retention).

Instead, getting on top of perimenopause requires managing heavy and unscheduled bleeding, symptom relief, and, where needed, contraception, as the ovaries are still randomly producing eggs.

Can blood tests individualise hormone therapy?

No. Blood hormone tests can’t determine whether you might benefit from menopause hormone therapy or what dose you might need.

People’s oestrogen receptors have different levels of sensitivity and are turned up and down by other proteins and hormones in the cells. So even achieving the same blood oestradiol level with oestrogen therapy can have completely different effects in different people.

Individuals also respond differently to prescribed oestrogen, whether it’s tablet or through the skin. For transdermal patches or gels, the temperature of the skin, exercise, skin hydration and site of application affect absorption.

After absorption, oestradiol is metabolised rapidly to other oestrogens which are not measured in a standard blood test. So the total amount of oestrogen circulating is not determined by simply measuring blood oestradiol.

Do you need a blood test to check your dose?

No. There is no target blood oestradiol level that is right for everyone, and no established blood level that will prevent bone loss, heart disease or dementia.

Nor is there a perfect time of day to measure oestradiol, as the pattern of absorption of oestrogen over 24 hours varies, especially with transdermal oestradiol.

Plus, different commercial laboratories use different measurement systems so you cannot always directly compare test results between laboratories.

What about progestogen and testosterone?

Progestogens, including progesterone, are required to protect against thickening of the uterine lining by oestrogen.

The type and dose of progestogen needed can vary substantially and this cannot be predicted, or fine tuned, by a blood test.

For testosterone, there is no cut-off below which a woman can be diagnosed as having “insufficient testosterone”.

Whether hormone therapy involves oestrogen, progesterone or testosterone, for women who experience natural menopause after the age of 45, diagnosis and treatment is determined on symptoms, not blood hormone levels.

Susan Davis, Chair of Women’s Health, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Featured Image: Photo by Centre for Ageing Better on Unsplash