Primary Ovarian Insufficiency

Primary ovarian insufficiency is loss of normal ovarian function before the age of forty. It causes amenorrhoea, or in a proportion irregular, declining menstrual function before complete amenorrhoea, together with hypergonadotropic hypogonadism.

It is an important, distinct cause of premature ovarian failure. It warrants careful, full evaluation because of its substantial implications for fertility, bone health, cardiovascular risk, and quality of life.

There is a range of underlying causes:

• genetic conditions (particularly Turner syndrome and fragile X premutation)
• autoimmune ovarian destruction
• iatrogenic causes (including chemotherapy, radiotherapy, or bilateral oophorectomy)
• in a substantial proportion of cases, no clearly identifiable cause (idiopathic disease)

Pathophysiology and classification

• Primary ovarian insufficiency reflects premature depletion or dysfunction of the ovarian follicular reserve. Oestrogen production falls.
• Loss of the normal negative feedback of oestrogen on the hypothalamic-pituitary axis characteristically elevates gonadotropins (follicle-stimulating hormone and luteinising hormone).
• This distinguishes the condition biochemically from hypothalamic or pituitary causes of amenorrhoea, where gonadotropin levels are characteristically low or inappropriately normal.
• Genetic causes include Turner syndrome, an important cause particularly in primary amenorrhoea presentations, and fragile X premutation carrier status.
• Female fragile X premutation carriers have a substantially increased risk of primary ovarian insufficiency. Test in appropriately selected cases. The result also matters for family reproductive counselling, because of the fragile X syndrome association in male offspring.
• Autoimmune ovarian destruction is an identifiable cause in a proportion of cases. It sometimes occurs in isolation and sometimes as part of a broader autoimmune polyendocrine syndrome, with a recognised association with autoimmune thyroid disease and, less commonly, adrenal insufficiency. Screen specifically where relevant.
• Iatrogenic causes include gonadotoxic chemotherapy (particularly alkylating agents) or pelvic radiotherapy given for malignancy or another condition, and bilateral oophorectomy for a gynaecological indication.
• Counsel proactively before the causative treatment and, where relevant and feasible, discuss fertility preservation.

• Secondary amenorrhoea is the core, defining presenting feature. Primary amenorrhoea is less common and occurs where the condition develops before menarche.
• Amenorrhoea is often preceded by irregular, increasingly infrequent menstruation, reflecting declining, fluctuating ovarian function before complete cessation.
• Symptoms of oestrogen deficiency closely resemble those of natural menopause and frequently accompany the menstrual disturbance. They include vasomotor symptoms (hot flushes and night sweats), vaginal dryness, and reduced libido.
• These symptoms develop at a substantially younger age than in natural, age-appropriate menopause.
• Infertility reflects the loss of normal ovarian follicular function. Its impact is often profound, given the young age of the affected woman and the substantial implications for her family planning and life circumstances.
• Where an underlying cause is identifiable, features specific to that cause may be present. Examples are the characteristic features of Turner syndrome, or symptoms of an associated autoimmune condition.
• A substantial proportion of affected women have no additional feature beyond the menstrual and oestrogen deficiency symptoms.

• Diagnosis requires amenorrhoea (or significant menstrual irregularity) persisting for at least four months, with an elevated follicle-stimulating hormone level in a woman under the age of forty.
• Measure follicle-stimulating hormone on two occasions at least four to six weeks apart, because gonadotropin levels can fluctuate, particularly in the earlier stages.
• Once the diagnosis is confirmed, assess fully for an underlying cause. This includes karyotype analysis (screening for Turner syndrome or other chromosomal abnormality), fragile X premutation testing, and screening for autoimmune conditions (thyroid function testing and, where clinically relevant, adrenal antibody testing).
• Review any previous chemotherapy, radiotherapy, or pelvic surgery.
• Anti-Müllerian hormone measurement reflects the ovarian follicular reserve and may give additional, supportive information. The diagnosis rests on the clinical presentation with the characteristic biochemical pattern of amenorrhoea with elevated gonadotropins.
• Bone density assessment (dual energy x-ray absorptiometry) is a standard component of evaluation, given the direct relevance of oestrogen deficiency to bone health.

• Hormone replacement therapy is standard, essential treatment. It comprises oestrogen with, in women with an intact uterus, progestogen. Generally continue it until at least the average age of natural menopause.
• It treats the symptomatic consequences of oestrogen deficiency. It also protects bone health and, based on accumulating evidence, cardiovascular health.
• This protection matters because these women would otherwise have a substantial, prolonged duration of oestrogen deficiency compared with women reaching natural menopause at the typical, later age.
• Fertility counselling is an essential component of care, given the profound significance of infertility for many affected women.
• Oocyte donation is the primary route to biological pregnancy for the substantial majority of affected women who wish to pursue it.
• A small minority of women with intermittent, residual ovarian function have a recognised, though low, possibility of spontaneous pregnancy even after diagnosis. Counsel on ongoing contraceptive needs where pregnancy is not currently desired.
• Manage bone health with adequate calcium and vitamin D intake alongside hormone replacement therapy, and regular bone density monitoring. Prolonged oestrogen deficiency has direct consequences for bone health in this population.
• Manage any identified underlying cause, including appropriate treatment of an associated autoimmune condition.
• Offer genetic counselling where a genetic cause is identified. It addresses implications for the individual, family members and future reproductive planning.
• Provide psychological support. The diagnosis often has a profound emotional impact, given its implications for fertility and its frequently unexpected, premature timing relative to the woman's expected life stage.
• Connect women with specialist services and patient support organisations as part of compassionate, holistic management.