Menopausal hormone therapy (also known as hormone replacement therapy or HRT) is the terminology used for prescription medications containing female hormones. The purpose of MHT is to relieve symptoms relating to oestrogen (female hormone) deficiency.
MHT is prescribed as oestrogen alone therapy (in women who have undergone hysterectomy), oestrogen and progesterone therapy (in women who have a uterus) and in special circumstances, testosterone may also be included.
Southern Cross gratefully acknowledges this article's authors: Drs Megan Ogilvie and Stella Milsom of Fertility Associates, Auckland.
During menopause, levels of oestrogen and progesterone production gradually decrease. As a woman’s body adjusts to these changing hormone levels, menopausal symptoms -commonly hot flushes, increasingly erratic periods, night sweats and disturbed sleep, and vaginal dryness and discomfort - can occur. Other symptoms may include joint aching, mood change, anxiety and fatigue. During and after the menopausal transition women also lose bone density and the risk of osteoporosis increases.
The duration and intensity of menopausal symptoms varies considerably between women. The average duration of symptoms is seven and a half years after the last menstrual period. Some women are symptomatic even before periods become irregular. For a small percentage of women (about 20%) symptoms persist into later life. Some women pass through the menopause without noticing any symptoms; other women report severe symptoms.
How MHT is prescribed
The hormone that alleviates unpleasant menopause symptoms is oestrogen. New Zealand has natural, “body-identical” oestrogen (oestradiol) available which can be prescribed in tablet, patch or vaginal pessary or cream formulation. Progesterone is needed in all women with a uterus (unless only vaginal oestrogen is prescribed) to balance the oestrogen and is usually prescribed as a tablet or as an intrauterine device (Mirena and Jaydess IUD).
Some formulations are fully funded and some involve a part charge. Not all delivery methods are appropriate for all women. Some regimens mimic the menstrual cycle, so that monthly bleeding occurs. Continuous combined oestrogen and progesterone leads to an absence of periods in most women. Your doctor will be able to discuss the pros and cons of various formulations.
Oestrogen gel, oestrogen implants and a combined oestrogen and progesterone patch have limited availability in New Zealand and are not funded.
MHT benefits and risks/side effects
Benefits of MHT include:
- Relief from menopausal symptoms - oestrogen is the most effective treatment for menopausal symptoms
- Treatment of vaginal dryness, discomfort, urinary frequency and urgency associated with menopause
- Protection and treatment for lowered bone density (osteoporosis).
Risks of adverse events are very small in healthy women, and vary depending on whether oestrogen is given alone or in combination with progesterone:
- 4-7/additional venous clots per 10,000 women treated per year (oestrogen delivered by a patch or gel has not been associated with any venous clot risk)
- Oestrogen and progesterone MHT may possibly increase breast cancer risk in some women by 1 additional event per 1200 women per year after 5 years of treatment after the age of 50 years. Risk returns to baseline a few years after stopping MHT
- Oestrogen only MHT does not increase breast cancer risk
- For women over the age of 60 years there may be a small increased risk of a heart attack or a stroke. This small risk is likely even less if estrogen is delivered via low dose patch (< 50 ug per day)
- There can be breast tenderness and some dysfunctional bleeding. Dose adjustments can usually minimise or alleviate these side effects.
How to use MHT
Oestrogen treats the menopausal symptoms and protects bone density. The progesterone component controls menstrual bleeding and protects from cancer of the endometrium (lining of the womb). Women who have had a hysterectomy are most often prescribed oestrogen alone. Women who have a uterus need progesterone as well as the oestrogen. MHT is not contraceptive.
Before prescribing MHT the doctor will take a full medical history. The following are relative contraindications for MHT and a woman should advise her doctor if there is any history of the following:
- Breast Cancer
- Endometrial cancer
- Previous clots in the legs or the lungs (deep vein thrombosis or pulmonary embolus)
- Previous heart attack or stroke
If any of these conditions are present, consideration should be given to prescribing non hormone alternatives.
Continuing on MHT
Once the appropriate dose and route of MHT has been established (sufficient to provided symptom relief without side effects), it is recommended that a woman has an annual check up with her doctor. At each follow up, the doctor will monitor weight, blood pressure and perform a breast examination.
There is no set duration of treatment; each year a woman and her doctor will assess benefits of treatment versus any small risks based on the woman’s individual health and medical history. It is suggested that women consider a wean off MHT from time to time to see if MHT continues to be required.
Many women will only require treatment for a few years and most will come off MHT by their late 50s or early 60s. However, age alone will not dictate the discontinuation of treatment. If longer term therapy is considered necessary for adequate symptom relief, ie into the 7th decade of life, then it is recommended that consideration is given to forms of MHT associated with the least risks.
When women discontinue systemic MHT, discussion around the continuation or initiation of vaginal oestrogen is suggested as vaginal dryness and urinary irregularities are persistent in later menopause in at least 50% of women.
Treatment of Symptoms of the Menopause: An Endocrine Society Clinical Practice Guideline. American Endocrine Society, 2017 https://academic.oup.com/jcem/article/100/11/3975/2836060
The North American Menopause Society Guideline, 2017: http://www.menopause.org/docs/default-source/2017/nams-2017-hormone-therapy-position-statement.pdf
The Australasian College of Obstetrics and Gynaecology guideline, 2015 https://www.ranzcog.edu.au/RANZCOG_SITE/media/RANZCOG-MEDIA/Women%27s%20Health/Statement%20and%20guidelines/Clinical%20-%20Gynaecology/Menopausal-Hormone-Therapy-Advice-(C-Gyn-16)-Re-write-July-2015.pdf?ext=.pdf
Last Reviewed – November 2018