Premature Ovarian Insufficiency (POI)

POI (formerly called premature ovarian failure) occurs when the ovaries stop functioning normally before age 40. It is characterized by menstrual irregularity or cessation, elevated FSH (>25 IU/L), low estradiol, and very low AMH. It affects roughly 1% of women under 40.

Causes include autoimmune conditions, chromosomal abnormalities (Turner syndrome, fragile X premutation), prior chemotherapy or radiation, or are idiopathic. Unlike natural menopause, intermittent ovarian function and even spontaneous pregnancy (5–10% lifetime rate) are possible.

Hormone replacement therapy is recommended for symptom management and bone/cardiovascular protection. Fertility options include donor eggs, which offer high success rates.