Menopausal Hormone Therapy

Hormone Replacement Therapy (HRT) or menopausal hormone therapy (MHT), is  composed of hormones normally produced by the ovary. The aim of MHT is to give back a little bit of the hormones that are fluctuating, declining, and lost during the perimenopause and menopause respectively.  The changes in these hormones cause the symptoms outlined previously.

There are different forms of MHT:

  • Combined MHTin the form of oestrogen and progesterone
  • Oestrogen-only MHT
  • Testosterone
  • Other medications with similar effects such as Tibolone and SERMs

Some of these products are synthetic versions of the hormones naturally produced by the ovary, whereas other products are identical in structure to the hormones naturally produced by the ovary (bioidentical or body-identical).

MHT can be taken via the mouth as a tablet; via the skin as a patch, gel or spray; and vaginally as a tablet, cream, gel or ring. The most common form of MHT is a version of oestrogen and progesterone in combination as progesterone is necessary to protect the lining of the womb from continuous exposure to oestrogen which could lead to a build-up of the lining of the womb (endometrium), which could eventually lead to endometrial cancer. Women who have had a previous hysterectomy usually have oestrogen-only MHT as progesterone is no longer required for womb protection.

There are further subcategories of combination MHT depending on whether you are perimenopausal or postmenopausal.

The last decade has seen significant changes in MHT prescribing, taking into consideration the cardiovascular “timing hypothesis”, “window of opportunity” and transdermal oestrogen (oestrogen via the skin).

The “timing hypothesis” and “window of opportunity” relate to results from studies which show that when MHT is started within 10 years of the menopause, or before the age of 60, the benefits of MHT generally outweigh the risks of treatment for most people, particularly in reducing the risk of cardiovascular disease.

In addition, studies have shown that oestrogen via the skin does not increase the risk of blood clots at standard doses..

There is no definite time-limit on the duration of treatment with MHT. It is entirely an individual decision which will depend on the presence of ongoing symptoms, personal choice, and an understanding of the risks and benefits which can change over time.

Benefits of MHT:

  • Improves symptoms of peri/menopause – its main indication of use
  • Improves bone mineral density
  • Lowers the risk of cardiovascular disease if started either within 10 years of the menopause or under the age of 60 years
  • Reduces the risk of endometrial cancer  (continuous combined MHT only)
  • Reduces the risk of colorectal cancer (combined MHT only)

Disadvantages of MHT:

  • Spotting or irregular vaginal bleeding. This usually settles with time or a change in regimen, but on occasions might warrant further investigations which can be associated with complications
  • Small increased risk of blood clots and stroke with oral oestrogen
  • Small increased risk of breast cancer which is duration dependent. This varies with different types of MHT.
  • Individual hormonal side-effects such as tender breasts, nausea, headaches, mood changes, bloating. These usually settle with time or changes.

Contraindications to MHT

  • Recent heart attack or poorly controlled angina
  • Recent VTE event (for example, stroke, blood clot or clot in the lung)
  • Suspected or active breast cancer, endometrial cancer, or a hormone-sensitive cancer
  • Severe or active liver disease
  • Irregular non-investigated vaginal bleeding