Premature Ovarian Insufficiency (POI)

Definition

• Incidence: approximately 1-3.5% of women (recent 2024 ESHRE guideline revises the prevalence upward to 3.5%)
• Over 75% of women with POI have at least intermittent vasomotor and other symptoms

Pathophysiology

1. Decreased follicular endowment - fewer primordial follicles from the outset
2. Accelerated follicular atresia - faster-than-normal depletion (e.g., Turner syndrome)
3. Follicle dysfunction - follicles present but non-functional (e.g., FSH receptor mutations - "Savage syndrome")

Etiology

FMR1 Premutation - Key Points

• CGG repeat 55-200 (full mutation >200 is NOT associated with POI)
• POI risk: 13-26% of premutation carriers
• Risk increases with repeat size between 59-99, then plateaus at ~100
• Premutation is unstable and can expand to full mutation in offspring (fragile X syndrome), especially if >100 repeats
• Prevalence in sporadic POI: 0.8-7.5%; in familial POI: up to 13%

Clinical Features

• Vasomotor symptoms: hot flushes, night sweats (>75% of cases)
• Menstrual disturbance: oligomenorrhea, amenorrhea (secondary if after normal puberty; primary if before)
• Emotional lability, depression (psychological support is critical at diagnosis)
• Infertility
• Dyspareunia, vaginal dryness (hypoestrogenism)
• If onset before puberty: absence of secondary sexual characteristics (requires exogenous HRT to develop normally)
• If onset after puberty: secondary sexual characteristics are present

Diagnosis

Workup after POI is confirmed:

• Karyotype (to detect Turner syndrome, mosaicism, Y-chromosome material)
• FMR1 CGG repeat analysis (in all cases)
• Adrenal antibodies by indirect immunofluorescence - identifies the ~4% with steroidogenic cell autoimmunity at risk for Addison disease
• Thyroid antibodies / TSH (thyroiditis is most common autoimmune association)
• AMH - may assist in diagnosis and quantifying residual ovarian reserve
• DEXA scan - bone density at baseline

Consequences and Long-Term Health Risks

Management

Hormone Therapy (HT) - Cornerstone of Treatment

• Indicated in all women with POI (unless contraindicated) until at least the natural age of menopause (~51 years)
• Restores estrogen to physiological levels; protects bone and cardiovascular health
• Standard combined OCP can be used; dedicated HRT regimens may be more cardioprotective
• Transdermal estrogen preferred (avoids first-pass hepatic effects, more physiological)
• Progestogen required for uterine protection (for women with a uterus)
• Testosterone therapy - updated guidance from 2024 ESHRE includes specific recommendations for low libido in POI
• Surprisingly, women with POI may still conceive while taking exogenous hormones - do not rely on HRT for contraception

Fertility

• Oocyte donation / embryo donation are the only proven effective fertility treatments
• No convincing evidence that adjuvant therapies (gonadotropins, etc.) successfully induce ovulation once POI is established
• In vitro activation of primordial follicles is experimental
• Women with Turner syndrome considering donor oocyte pregnancy must be counseled about markedly increased risk of aortic rupture during pregnancy

Bone Health

• HRT is the primary intervention
• DEXA at diagnosis and monitoring thereafter
• Calcium and vitamin D supplementation as needed

Psychological Support

• Depression is common; counseling and support groups are important
• Peer support (women with lived experience informing care) is now specifically included in the 2024 guideline

Iatrogenic POI Prevention

• GnRH agonist (e.g., leuprolide) co-administration with cyclophosphamide lowers risk of POI in women receiving alkylating agents (conditionally recommended in rheumatology/oncology guidelines)
• Fertility preservation (oocyte/embryo cryopreservation) before gonadotoxic therapy

Key Points Summary

• POI ≠ absolute ovarian "failure" - function can resume; 5-10% spontaneous pregnancy rate
• Always screen for FMR1 premutation (affects offspring counseling) and adrenal autoimmunity
• HRT is the most important treatment and should continue until natural menopause age
• Oocyte donation is the only proven fertility option

• Berek & Novak's Gynecology, pp. 1880-1882
• Goldman-Cecil Medicine, pp. 2558-2559
• The 2024 ESHRE/ASRM/IMS evidence-based POI guideline (Panay et al., Climacteric 2024, PMID: 39647506) - 145 recommendations, updates diagnosis threshold and expands guidance on testosterone and AMH

1. What Is POI? - Plain-language definition, key statistics including the 3.5% revised prevalence
2. Symptoms - Colour-coded table covering vasomotor, psychological, sexual, and reproductive symptoms
3. How Is It Diagnosed? - Diagnostic criteria table (aligned to 2024 ESHRE guideline - one FSH >25 IU/L), plus full list of additional workup tests
4. Causes - Structured table covering chromosomal, genetic, autoimmune, iatrogenic, and idiopathic categories
5. Long-Term Health Risks - Bone, cardiovascular, cognitive, and sexual health
6. Hormone Therapy - Detailed table of all oestrogen routes and forms, progestogen, testosterone; includes the key message that HT in POI is replacement, not treatment of ageing
7. Fertility & Family Planning - Spontaneous pregnancy, oocyte donation, embryo donation, fertility preservation; Turner syndrome pregnancy warning
8. Monitoring & Follow-Up - Annual review checklist items
9. Questions to Ask Your Doctor - Ready-to-use checklist
10. Support & Resources - Daisy Network, ESHRE, IMS, BMS, Fragile X Society
11. Glossary - Plain-English definitions of all clinical terms