Premature Ovarian Insufficiency (POI)

What happens in POI

The ovaries contain a reserve of egg-containing follicles that produce estrogen and release eggs each cycle. In POI, the follicles are depleted early or do not respond to the brain's hormonal signals (FSH and LH). As a result:

• estrogen levels fall
• FSH rises as the brain tries to stimulate the ovaries
• ovulation becomes infrequent or stops

Function can come and go: about half of women with POI have occasional ovarian activity, and some ovulate.

POI vs menopause

Early menopause describes menopause between 40 and 45.

Causes

• unknown (idiopathic): the majority of cases
• genetic: - Turner syndrome and other X chromosome changes - fragile X premutation (FMR1), present in a notable minority of women with POI, important for family testing - other gene variants
• autoimmune: the immune system attacks the ovaries; often with autoimmune thyroid disease, Addison's disease or type 1 diabetes
• medical treatment: chemotherapy, pelvic radiation, ovarian surgery
• infections such as mumps (rare)
• metabolic disorders such as galactosemia

Symptoms

• irregular, infrequent or absent periods
• hot flashes and night sweats
• vaginal dryness and pain with sex
• sleep problems
• low mood, anxiety, irritability, poor concentration
• reduced sex drive
• infertility

Some women have few symptoms, and POI is found during fertility investigations.

Diagnosis

According to the 2024 ESHRE/ASRM guideline, POI is diagnosed with:

1. disordered periods (missed or infrequent periods) for at least 4 months, and
2. raised FSH (above 25 IU/L) on one test (a second test is not mandatory in the updated guideline but may be done)

Additional tests:

• pregnancy test, prolactin and thyroid function (to rule out other causes)
• estradiol and anti-Müllerian hormone (AMH)
• chromosome analysis (karyotype) and fragile X (FMR1) testing
• autoimmune screening: thyroid antibodies, adrenal antibodies
• bone density scan (DEXA)
• pelvic ultrasound

Treatment

Hormone replacement

Estrogen replacement, with progestogen to protect the uterus, is recommended for women with POI until around the average age of natural menopause (about 51). It:

• relieves hot flashes, vaginal dryness and mood symptoms
• protects bone density, reducing osteoporosis risk
• likely reduces cardiovascular risk associated with early estrogen loss

Options include standard menopausal hormone therapy or combined birth control pills. The risks of hormone therapy in women over 50 (such as breast cancer) do not apply in the same way to younger women replacing hormones they would naturally have.

Bone and heart health

• weight-bearing exercise
• calcium and vitamin D
• not smoking, and managing blood pressure and cholesterol

Fertility

• a small chance of spontaneous pregnancy remains, so contraception is needed if pregnancy is not wanted
• IVF with donor eggs has high success rates
• fertility preservation (egg or embryo freezing, ovarian tissue freezing) before cancer treatment or in women with known genetic risk, while ovarian function remains
• adoption and other paths

Emotional support

A POI diagnosis can be devastating. Counseling, support groups and clear information help women adjust.

Long-term health

Without estrogen replacement, POI increases the risk of osteoporosis, heart disease and possibly cognitive decline. With treatment and monitoring, these risks are reduced.

Frequently asked questions

What is premature ovarian insufficiency?

It is when the ovaries stop functioning normally before age 40, causing low estrogen, irregular or absent periods and reduced fertility. Unlike menopause, ovarian function may come and go.

Can you get pregnant with POI?

Yes, about 5% to 10% of women with POI conceive naturally because the ovaries sometimes still release eggs. IVF with donor eggs gives much higher pregnancy rates. Use contraception if you do not want to become pregnant.

What causes premature ovarian insufficiency?

Often no cause is found. Known causes include genetic conditions such as Turner syndrome and fragile X premutation, autoimmune disease, and chemotherapy or radiation. Rarely, infections or metabolic conditions are responsible.

Do I need hormone therapy for POI?

Hormone therapy is recommended until about age 51 for most women with POI. It replaces missing estrogen, relieves symptoms and protects bones and heart. Your doctor will tailor the type and dose to you.