Primary ovarian insufficiency: menopause before 40

Why the name changed from premature menopause

The term primary ovarian insufficiency replaced premature ovarian failure for a reason that matters clinically. Menopause is permanent. Primary ovarian insufficiency is often not: ovarian activity can fluctuate, periods can return after months of absence, and ovulation occurs intermittently in a significant minority.

Spontaneous pregnancy occurs in roughly 5 to 10% of women with the diagnosis. That figure carries two practical consequences in opposite directions. Contraception is still needed by anyone not seeking pregnancy. And the diagnosis is not the absolute end of fertility that the old name implied, though it should not be presented as grounds for optimism either.

How it is diagnosed

The standard criteria are four or more months of absent or markedly irregular periods before the age of 40, together with a raised FSH in the menopausal range measured on two separate occasions at least four weeks apart.

The repeat test is not bureaucracy. A single raised FSH in a fluctuating system is not sufficient evidence for a diagnosis with lifelong implications.

Once confirmed, further investigation usually includes thyroid and adrenal autoantibodies, a karyotype and Fragile X premutation testing, because these change what else needs monitoring and what it means for female relatives.

Causes, and the honest answer about them

In most cases no cause is found. Of those where one is, the main categories are genetic, including Fragile X premutation and Turner syndrome and its variants; autoimmune, most often alongside thyroid or adrenal disease; and iatrogenic, from chemotherapy, pelvic radiotherapy or ovarian surgery.

Not finding a cause is the common outcome and is not a failure of investigation. It does not change the management.

Why hormone therapy is framed differently

For a woman of 32 with primary ovarian insufficiency, hormone therapy is not a treatment added on top of normal physiology. It replaces what her body would otherwise be producing for the next twenty years.

Guidance recommends hormone therapy, or the combined oral contraceptive as an alternative, at least until the average age of natural menopause, for bone and cardiovascular protection as much as for symptoms. The risk profile from trials conducted in women in their sixties simply does not transfer to this group, and being offered a short course and a discussion of breast cancer risk is a misapplication of that evidence.

Important caveat often missed: standard hormone therapy is not reliable contraception. Anyone who needs contraception needs it addressed separately.

When to see someone

Four months or more of absent or very irregular periods before 40, once pregnancy is excluded, warrants FSH testing rather than reassurance.

Ask for referral to someone who manages this specifically. It sits between gynaecology, endocrinology and fertility medicine, and general reassurance from any one of them tends to be inadequate. Bone density monitoring and a long-term plan should both be part of the conversation.