Premature Ovarian Insufficiency

Premature Ovarian Insufficiency (POI) – previously known as premature ovarian failure or premature menopause – is a condition where the ovaries stop working normally before the age of 40.

A normal menopause occurs at around age 51. A menopause under 45 is considered early, and a menopause under 40 is premature. POI affects approximately 1 in 100 women under 40 and 1 in 1,000 women under 30.

It is important to understand that women with POI do not always stop menstruating completely, and their ovaries do not always stop working entirely. This is why the term “insufficiency” is now preferred over “failure” – some ovarian function may still remain.

Symptoms

The most common symptom is the absence of menstrual periods (amenorrhoea) or having infrequent periods (oligomenorrhoea).

You may also experience:

• Hot flushes and night sweats.
• Palpitations or heart racing.
• Headaches and fatigue.
• Mood changes, irritability, anxiety, or depression.
• Difficulty concentrating or memory problems.
• Sleep disturbance (insomnia).
• Reduced sex drive (libido).
• Vaginal dryness and pain during intercourse.
• Changes to skin and hair.
• Urinary symptoms (frequency, urgency, or recurrent infections).

Causes

• Genetic conditions – such as Turner’s syndrome or Fragile X premutation.
• Autoimmune disorders – where the body mistakenly attacks its own ovarian tissue.
• Surgical removal of the ovaries (oophorectomy).
• Radiotherapy or chemotherapy – cancer treatments that can damage ovarian function.
• Toxins – including cigarette smoke, chemicals, and some viruses.

In approximately 90% of spontaneous cases, the reason remains unknown.

Why Does POI Matter?

Oestrogen – the main hormone produced by the ovaries – is essential for:

• Bone health – keeping bones strong and preventing osteoporosis.
• Heart and blood vessel health – protecting against cardiovascular disease.
• Fertility and egg production.
• General wellbeing – including mood, skin, and vaginal health.
• Cognitive health – preventing memory and concentration difficulties.

Diagnosis

POI is diagnosed if you meet the following criteria:

• Age under 40 at time of diagnosis.
• Absent or infrequent periods for at least 4 months.
• Elevated FSH (follicle-stimulating hormone) level above 25–30 IU/L on two separate occasions, measured at least 4–6 weeks apart.
• Karyotype (chromosome analysis) – to check for genetic abnormalities such as Turner’s syndrome.
• Fragile X premutation testing – as this is found in 0.8–7.5% of women with POI.
• Thyroid peroxidase (TPO) antibodies – to check for autoimmune thyroid disease.

Treatment Options

The current recommendation is that all women with POI should be offered hormone replacement therapy (HRT), unless there is a specific medical reason not to take it.

• HRT reduces the risk of cardiovascular disease and osteoporosis.
• HRT relieves menopausal symptoms such as hot flushes, night sweats, mood changes, and vaginal dryness.
• HRT does not increase breast cancer risk above the baseline risk of a woman of the same age with normal ovarian function.
• HRT should be continued until at least the average age of natural menopause (around 51).
• Combined Oral Contraceptive (COC) pill can be used as an alternative, but HRT may offer better bone and heart protection.

Fertility and Pregnancy

POI usually results in infertility, as the ovaries stop releasing eggs regularly.

However, spontaneous ovulation and pregnancy can occur rarely – around 5–10% of women with unexplained POI may still ovulate occasionally and become pregnant.

Options if you wish to have children:

• IVF with donor eggs – the most common route.
• Using your own eggs – if you had eggs frozen before ovarian failure.
• Surrogacy or adoption – alternative family-building options.