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Q1: Define PCOS and state how you diagnose it (2 min)
PCOS is a heterogeneous syndrome of reproductive and metabolic dysfunction — the commonest endocrine disorder of reproductive-age women (prevalence around 8 to 13 percent), driven by insulin resistance and hyperandrogenism.
Diagnosis uses the Rotterdam (2003) criteria — TWO OF THREE, after excluding mimics:
- Oligo- or anovulation (cycles over 35 days or fewer than 8 per year).
- Clinical or biochemical hyperandrogenism (hirsutism, acne, androgenic alopecia; elevated free testosterone / free androgen index).
- Polycystic ovarian morphology on ultrasound (adults: 20 or more follicles per ovary of 2 to 9 mm and/or ovarian volume over 10 mL on the modern AE-PCOS threshold).
Mimics to exclude: thyroid disease, hyperprolactinaemia, Cushing syndrome, non-classic CAH (17-OHP), androgen-secreting tumour, premature ovarian insufficiency.
Q2: Explain the pathophysiology — why a "vicious cycle"? (3 min)
- Increased GnRH pulse frequency raises LH relative to FSH.
- High LH stimulates ovarian theca cell hyperplasia, increasing androgen (testosterone, androstenedione) production.
- Insulin resistance → hyperinsulinaemia drives hyperandrogenism by THREE mechanisms: (1) augments LH action on theca cells; (2) lowers hepatic SHBG, raising FREE testosterone; (3) directly stimulates ovarian androgen synthesis.
- Relatively low FSH arrests follicular maturation → anovulation and accumulation of sub-capsular follicles (polycystic morphology).
- Anovulation → no luteal-phase progesterone → unopposed oestrogen (from peripheral aromatisation in adipose tissue) → endometrial hyperplasia.
- The insulin-resistance ↔ hyperandrogenism loop is self-reinforcing — hence "vicious cycle."
Q3: Outline management, symptom-driven and lifestyle-first (2 min)
- ALL patients — lifestyle first: 5 to 10 percent weight loss restores cycles and ovulation; diet, exercise, behaviour. The single most effective intervention.
- Cycle control / endometrial protection (not trying to conceive): combined OCP first-line (cycle regularity, raises SHBG, endometrial protection); cyclical progestogen if OCP contraindicated.
- Metabolic: metformin 1500 to 2000 mg/day for insulin resistance; screen and treat T2DM, dyslipidaemia, hypertension.
- Hirsutism/acne: combined OCP first-line; add cosmetic measures; anti-androgens (spironolactone 50 to 200 mg/day) ONLY with reliable contraception (teratogenic).
- Infertility: letrozole first-line (2.5 to 7.5 mg days 2 to 6; PPCOS II, NEJM 2014 — superior live-birth vs clomiphene); clomiphene second-line; gonadotrophins / laparoscopic ovarian drilling third-line; IVF for additional factors.
Q4: Long-term complications and what you must screen for (2 min)
- Metabolic: type 2 diabetes (around 4-fold), impaired glucose tolerance, dyslipidaemia, metabolic syndrome, non-alcoholic fatty liver disease, obstructive sleep apnoea, hypertension.
- Reproductive: anovulatory infertility, recurrent early pregnancy loss, gestational diabetes, pre-eclampsia, preterm delivery.
- Endometrial: hyperplasia and endometrial cancer (around 3-fold) from chronic unopposed oestrogen — protect the endometrium.
- Psychological: anxiety, depression, eating disorders, reduced quality of life — screen actively.
Screen: fasting glucose / HbA1c (with 2-hour OGTT in overweight/high-risk), lipid profile, blood pressure, sleep apnoea symptoms, mood — repeat periodically.
Q5: Red flags and pitfalls (1 min)
- Sudden severe virilisation (clitoromegaly, voice deepening) + very high testosterone → NOT PCOS; image for androgen-secreting tumour.
- Prolonged amenorrhoea without endometrial protection → endometrial hyperplasia risk; induce withdrawal bleeds.
- Spironolactone without contraception → teratogenic (feminises male fetus).
- Over-diagnosing adolescents — irregular cycles for up to 2 to 3 years post-menarche are normal; do not apply adult PCOM criteria.
- Treating hirsutism for less than six months and declaring failure — hair cycles are slow; reassess at six months.