Detailed definition
Primary ovarian insufficiency (POI), formerly called premature ovarian failure (POF), is the loss of normal ovarian function before age 40. Diagnostic criteria are oligomenorrhea or amenorrhea for at least 4 months plus FSH in the postmenopausal range (>25–40 mIU/mL on two occasions at least 4 weeks apart). Prevalence is approximately 1% in women under 40 and 0.1% under 30. Causes include: chromosomal/genetic (Turner syndrome, fragile X premutation, FMR1-related, BRCA mutations); autoimmune (often associated with adrenal autoimmunity, autoimmune thyroid disease, type 1 diabetes); iatrogenic (chemotherapy, pelvic radiation, ovarian surgery); and idiopathic, which accounts for about 70% of cases. POI is distinct from menopause in that ovarian function may fluctuate — roughly 5–10% of women with POI conceive spontaneously after diagnosis, so contraception remains relevant if pregnancy is undesired. Long-term, women with POI face elevated risks of osteoporosis, cardiovascular disease, dementia, and earlier mortality if untreated.
Why it matters in menopause
For women with POI, HRT is not the same kind of decision as it is for women in their 50s. The body should still be producing ovarian estrogen, and replacement protects organ systems that are vulnerable to a 10–20 year head start of estrogen deprivation. Standard practice is to continue HRT at full physiologic doses until at least the average age of natural menopause (around 51), then re-evaluate.
Related terms
Sources
External references: Wikipedia.