📋 Key Information Summary
- PCOS affects approximately 8–13% of reproductive-age women in Australia, depending on the diagnostic criteria applied; prevalence rises to 20–30% when ultrasonography alone is used to define polycystic ovarian morphology.
- Diagnosis requires ≥2 of the following Rotterdam Criteria: clinical/biochemical hyperandrogenism, oligo-anovulation (≤9 menses/year or cycles >35 days), and polycystic ovarian morphology on ultrasound (≥20 follicles per ovary or ovarian volume >10 mL).
- Exclusion of mimicking conditions (thyroid disease, hyperprolactinaemia, Cushing syndrome, late-onset congenital adrenal hyperplasia, androgen-secreting tumours) is mandatory before diagnosing PCOS.
- Insulin resistance and compensatory hyperinsulinaemia are central to PCOS pathophysiology and drive ovarian androgen excess.
- Clinical features include menstrual irregularity, hirsutism, acne, alopecia, and subfertility; metabolic complications include type 2 diabetes, dyslipidaemia, and cardiovascular risk.
- Screening for dysglycaemia (OGTT) is recommended every 1–3 years from age 30 (or at diagnosis if BMI >25) and annually if impaired glucose tolerance is present.
- Weight management with lifestyle modification is the first-line treatment regardless of presenting complaint; even 5–10% weight loss significantly improves metabolic and reproductive outcomes.
- Combined oral contraceptive pill (COCP) is first-line pharmacotherapy for menstrual irregularity and hyperandrogenism; levonorgestrel-ethinylestradiol preparations (such as Lenette-30ED®) are commonly used in Australia.
- Metformin (PBS-Listed) is considered second-line for metabolic features or when COCP is contraindicated; standard dose 500–2000 mg daily.
- Counselling regarding long-term metabolic and endometrial health is essential; unopposed oestrogen in oligomenorrhoeic women increases endometrial hyperplasia risk.
- Clomiphene citrate or letrozole are first-line ovulation induction agents for women with PCOS-related anovulatory subfertility; letrozole has superior live-birth rates per the NICE and ASRM guidelines.
- PCOS prevalence is higher in Aboriginal and Torres Strait Islander women, with greater metabolic complications and limited access to specialist care in remote settings.
🎧 Audio Brief
Introduction & Australian Epidemiology
Polycystic Ovarian Syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, characterised by a triad of hyperandrogenism, oligo-anovulation, and polycystic ovarian morphology. The disorder is now recognised as a lifelong condition with metabolic, reproductive, and psychological implications that extend well beyond the reproductive years.
In Australia, prevalence estimates vary with the diagnostic criteria applied. Using the Rotterdam criteria, prevalence is approximately 8–13%, while the NIH 1990 criteria (which require both hyperandrogenism and oligo-anovulation) yield a lower prevalence of 6–8%. When ultrasonographic criteria alone are applied, prevalence may reach 20–30%, though many of these women may be asymptomatic. The Australian Longitudinal Study on Women's Health identified PCOS as a significant contributor to quality-of-life impairment, with affected women reporting higher rates of depression, anxiety, and body-image dissatisfaction.
PCOS carries substantial public-health significance: affected women have a 2–3-fold increased risk of type 2 diabetes mellitus (T2DM), up to 7-fold increased risk of impaired glucose tolerance, and elevated cardiovascular risk markers. Endometrial hyperplasia and endometrial carcinoma risk is increased 2.7–4-fold due to chronic unopposed oestrogen exposure in anovulatory women. PCOS is also the leading cause of anovulatory subfertility in Australia, accounting for approximately 70% of cases of ovulatory dysfunction.
This guideline follows the 2023 International Evidence-Based Guideline for the Assessment and Management of PCOS, adapted for Australian primary-care practice, and aligns with RACGP Red Book screening recommendations, Therapeutic Guidelines (eTG) pharmacological management, and PBS-listed medications.
Pathophysiology & Diagnosis (Rotterdam Criteria)
Pathophysiology
PCOS is a polygenic, multifactorial disorder with a complex interplay of genetic predisposition, epigenetic modifications, and environmental influences. The central pathophysiological driver is insulin resistance, present in 50–80% of women with PCOS (lean and overweight), leading to compensatory hyperinsulinaemia.
- Ovarian steroidogenesis: Hyperinsulinaemia acts synergistically with luteinising hormone (LH) to stimulate theca-cell production of androgens (androstenedione and testosterone). Insulin also suppresses hepatic sex hormone–binding globulin (SHBG), increasing bioavailable free testosterone.
- Hypothalamic–pituitary axis: Increased GnRH pulse frequency favours LH over FSH secretion (elevated LH:FSH ratio), perpetuating androgen excess and impairing folliculogenesis.
- Adipose tissue dysfunction: Visceral adiposity amplifies insulin resistance through adipokine dysregulation (increased TNF-α, IL-6; decreased adiponectin), contributing to chronic low-grade inflammation.
- Genetic & epigenetic factors: Twin studies demonstrate heritability of 50–70%. Candidate genes involve steroidogenesis (CYP11A1, CYP17), insulin signalling (INSR, IRS1), and androgen metabolism. In-utero androgen exposure may programme offspring to develop PCOS features through epigenetic mechanisms.
- Gut microbiome: Emerging evidence suggests reduced microbial diversity in PCOS, with altered bile-acid metabolism contributing to insulin resistance and inflammation.
Diagnostic Criteria — 2003 Rotterdam Consensus
Diagnosis requires the presence of at least 2 of 3 criteria, after excluding other causes of androgen excess or oligomenorrhoea:
| Rotterdam Criterion | Definition | Diagnostic Threshold |
|---|---|---|
| 1. Oligo-anovulation | Infrequent or absent ovulation | ≤9 menstrual cycles/year, or cycles >35 days |
| 2. Clinical and/or biochemical hyperandrogenism | Excess androgen signs or levels | Hirsutism (Ferriman–Gallwey ≥6), acne, alopecia; or total testosterone >2.0 nmol/L, free testosterone >35 pmol/L (lab-specific) |
| 3. Polycystic ovarian morphology (PCOM) | Characteristic ultrasound findings | ≥20 follicles per ovary (2–9 mm), or ovarian volume >10 mL (transvaginal ultrasound preferred) |
Exclusion diagnoses required before diagnosing PCOS: Thyroid dysfunction (TSH), hyperprolactinaemia (prolactin), non-classical congenital adrenal hyperplasia (17-OH progesterone), Cushing syndrome (if clinical suspicion), androgen-secreting tumours (if rapid-onset virilisation). Pregnancy must be excluded in all reproductive-age women.
PCOS Phenotypes (AE-PCOS Society)
| Phenotype | Hyperandrogenism | Oligo-anovulation | PCOM | Metabolic Severity |
|---|---|---|---|---|
| A (Classic) | ✔ | ✔ | ✔ | Most severe |
| B (Classic) | ✔ | ✔ | – | Severe |
| C (Ovulatory) | ✔ | – | ✔ | Moderate |
| D (Non-hyperandrogenic) | – | ✔ | ✔ | Mildest |
Clinical Features & Complications
Reproductive Features
- Menstrual irregularity: Presenting symptom in 70–80% of adolescents and adults. Oligomenorrhoea (cycles >35 days) is most common; primary amenorrhoea may occur in severe phenotypes.
- Subfertility: Anovulation is the principal cause; cumulative fecundity per cycle without treatment is ~2% vs 15–20% in ovulatory women.
- Pregnancy complications: Increased rates of gestational diabetes (3-fold), pre-eclampsia, preterm birth, small- and large-for-gestational-age infants. Preconception counselling is essential.
Dermatological Features
- Hirsutism: Terminal hair growth in androgen-dependent areas (upper lip, chin, chest, abdomen, back, thighs). Assessed using the Ferriman–Gallwey modified score; ≥6 is abnormal. Affects 60–80% of women with PCOS.
- Acne: Inflammatory or comedonal acne, particularly adult-onset or treatment-resistant. Present in 20–35%.
- Androgenic alopecia: Female-pattern hair loss (frontal/vertex thinning); less common (5–15%) but psychologically impactful.
- Acanthosis nigricans: Hyperpigmented velvety plaques at neck, axillae, groin — a clinical marker of insulin resistance.
Metabolic Complications
Early
Dyslipidaemia
Elevated triglycerides, low HDL-cholesterol. Present in 70% of overweight women with PCOS.
Setting: GP screening with fasting lipids
Intermediate
Impaired Glucose Tolerance
IGT present in 30–40% of overweight PCOS women; 2–3-fold increased T2DM risk over 5–10 years.
Setting: GP with OGTT every 1–3 years
Severe
Type 2 Diabetes & CVD
T2DM risk 5–10× general population; increased carotid intima-media thickness, coronary artery calcification.
Setting: GP + Endocrinologist shared care
Psychosocial & Psychological
- Depression (OR 3.8) and anxiety (OR 5.6) significantly more prevalent than age-matched controls.
- Body image disturbance, disordered eating (binge eating disorder prevalence ~10%), and sexual dysfunction.
- Routine psychological screening using PHQ-9 and GAD-7 is recommended at diagnosis and periodically thereafter.
Endometrial Hyperplasia & Carcinoma
Chronic anovulation leads to unopposed oestrogen stimulation of the endometrium, increasing risk of endometrial hyperplasia (up to 4-fold) and endometrial carcinoma (2.7-fold). Young women (<40 years) with endometrial cancer are disproportionately represented by PCOS. Progesterone withdrawal bleeds (e.g., cyclic medroxyprogesterone acetate 10 mg for 10–14 days each cycle) or COCP use is recommended to achieve at least 4 withdrawal bleeds per year.
Investigations
Investigations serve dual purposes: excluding differential diagnoses and assessing metabolic/complication burden. The following workup is recommended for all women with suspected PCOS.
Baseline Diagnostic Workup
Essential
Serum total testosterone
MBS Item 66673. Free testosterone (calculated or equilibrium dialysis) if total is high-normal. Elevated in 60–80% of PCOS. Markedly elevated >5 nmol/L warrants ovarian/adrenal imaging to exclude tumour.
Essential
SHBG (sex hormone–binding globulin)
MBS Item 66673. Low in insulin-resistant PCOS. Used to calculate free androgen index (FAI = total testosterone ÷ SHBG × 100). FAI >5% indicates hyperandrogenism.
Essential
TSH
MBS Item 66708. Exclude hypothyroidism as a cause of oligomenorrhoea.
Essential
Prolactin
MBS Item 66686. Exclude hyperprolactinaemia.
Recommended
17-OH Progesterone
MBS Item 66673. Exclude non-classical congenital adrenal hyperplasia (NCCAH). Basal level <5 nmol/L effectively excludes NCCAH; if elevated, confirm with ACTH stimulation test.
Essential
Fasting glucose & fasting insulin (or OGTT)
MBS Item 66550 (glucose), 66544 (OGTT). HOMA-IR can be calculated. OGTT is preferred — more sensitive for IGT detection than fasting glucose alone.
Essential
Fasting lipid profile
MBS Item 66508. Assess dyslipidaemia (↑TG, ↓HDL).
Essential
Transvaginal ultrasound (TVS)
MBS Item 55041. Preferred modality; follicle count ≥20 per ovary or ovarian volume >10 mL defines PCOM. Note: PCOM alone does not diagnose PCOS — must be combined with another criterion.
Metabolic Surveillance Schedule
| Test | Frequency | When to Start |
|---|---|---|
| OGTT | Every 1–3 years | At diagnosis if BMI >25; otherwise from age 30 |
| Fasting lipids | Every 1–2 years | At diagnosis |
| HbA1c | Every 1–2 years | If OGTT impractical; not a substitute for OGTT if IGT screening is needed |
| BP & weight/BMI/waist | Annually | At every consultation |
| Liver function (NAFLD screening) | Every 1–2 years | If BMI >25 |
| Psychological screening (PHQ-9, GAD-7) | At diagnosis, then PRN | All patients at diagnosis |
Anti-Müllerian hormone (AMH): AMH is elevated in PCOS but is NOT recommended as a diagnostic test for PCOS in adults, as cut-offs lack standardisation. AMH is useful for assessing ovarian reserve in fertility contexts but should not replace follicle count on ultrasound for diagnostic purposes.
Management
Management of PCOS is individualised based on the patient's presenting concerns, phenotype, metabolic risk, and fertility goals. A holistic, multidisciplinary approach addressing lifestyle, pharmacotherapy, and psychological wellbeing is recommended.
1. Lifestyle Modification (First-Line for All)
Cornerstone of PCOS management: Lifestyle intervention is recommended as first-line therapy for all women with PCOS, regardless of BMI or presenting complaint. Even modest weight loss of 5–10% improves ovulation rates, reduces androgens, and improves insulin sensitivity.
- Physical activity: ≥150 minutes moderate-intensity or ≥75 minutes vigorous-intensity activity per week, with muscle-strengthening activities on ≥2 days (aligns with Australian Physical Activity Guidelines).
- Dietary intervention: No single optimal diet is superior. Emphasis on sustainable caloric deficit if overweight/obese, Mediterranean-style dietary pattern, glycaemic index awareness, and dietary quality improvement. Referral to an Accredited Practising Dietitian is recommended.
- Behavioural strategies: Motivational interviewing, cognitive-behavioural approaches, and multidisciplinary team support improve adherence.
2. Pharmacotherapy for Menstrual Irregularity & Hyperandrogenism
First-Line: Combined Oral Contraceptive Pill (COCP)
Ethinyloestradiol 30 µg + Levonorgestrel 150 µg
Lenette-30ED® · Generic · Monophasic COCP
Adult dose
1 tablet PO daily for 21 days, then 7 placebo/sugar-free days
Mechanism
Suppresses LH, reduces ovarian androgen production, increases SHBG, provides endometrial protection
Key precautions
Avoid if BMI >35 with additional VTE risk factors (smoking, age >40, FHx VTE). Monitor BP. Not suitable if actively seeking pregnancy.
PBS status
✔ PBS General Benefit
Cyproterone acetate 2 mg + Ethinyloestradiol 35 µg
Brend® · Generic · Anti-androgenic COCP
Adult dose
1 tablet PO daily for 21 days, then 7 days off
Indication
Preferred for moderate–severe hirsutism or acne not responding to levonorgestrel COCP
Key precautions
Higher VTE risk than levonorgestrel COCP. Contraindicated in active liver disease, meningioma risk. Avoid high-dose cyproterone (Diane-35® ≥2 mg CPA equivalent).
PBS status
✔ PBS General Benefit
Second-Line: Metformin
Metformin hydrochloride
Diabex® · Diaformin® · Glucophage® · Biguanide
Adult dose
500 mg PO BD with meals, titrate over 2–4 weeks to 850–1000 mg BD (max 2000 mg/day)
Indication in PCOS
Adjunct to lifestyle for metabolic features; if COCP contraindicated; BMI >25 with IGT
Renal adjustment
eGFR <30: contraindicated; eGFR 30–45: max 500 mg BD; eGFR <45: do not initiate
Side effects
GI (nausea, diarrhoea) — minimise with gradual titration and taking with food. Consider XR formulation.
PBS status
✔ PBS General Benefit (for T2DM); Not PBS-listed for PCOS indication specifically
Adjunctive Anti-Androgen Therapy
Spironolactone
Aldactone® · Spiractin® · Aldosterone antagonist
Adult dose
25 mg PO daily, titrate to 100–200 mg/day in 1–2 divided doses
Indication
Hirsutism not responding to 6–12 months of COCP alone. Must use reliable contraception (teratogenic).
Monitoring
U&E at baseline, 4 weeks, then 6-monthly. Hyperkalaemia risk, especially with renal impairment or ACE-I/ARB use.
PBS status
✔ PBS General Benefit
Cyproterone acetate (high-dose, off-label)
Androcur® · Anti-androgen
Adult dose
50–100 mg PO daily for days 1–10 of cycle, combined with ethinyloestradiol days 1–21 (Diane-35® equivalent approach)
Key precaution
Increased risk of meningioma with cumulative doses >60 g lifetime. Use only if spironolactone contraindicated/ineffective. TGA warning applies.
PBS status
✔ PBS General Benefit
3. Management of Hirsutism & Acne (Non-Hormonal)
- Eflornithine 13.9% cream (Vaniqa®): Topical application to face twice daily; reduces facial hair growth within 4–8 weeks. PBS Not Listed.
- Physical hair removal: Laser hair removal (alexandrite 755 nm or diode 810 nm) or IPL effective for terminal hair. 6–8 sessions required. Not PBS-listed.
- Topical retinoids & benzoyl peroxide: First-line for PCOS-related comedonal/inflammatory acne.
- Oral antibiotics: Doxycycline 50–100 mg PO daily or minocycline 50–100 mg PO daily for 3–6 months as bridge therapy for inflammatory acne while awaiting COCP effect.
4. Fertility & Ovulation Induction
Preconception optimisation (BMI <30 if possible, folic acid 5 mg daily, glycaemic control) should precede ovulation induction.
Letrozole
Femara® · Aromatase inhibitor
Adult dose
2.5 mg PO daily for days 2–6 of cycle. Titrate to 5–7.5 mg if no ovulation after 3 cycles.
Efficacy
Superior to clomiphene for live-birth rate (27.5% vs 19.1%; P=0.007). Recommended as first-line per NICE 2013, ASRM 2017, and International PCOS Guideline 2023.
Monitoring
Cycle-day-12 ultrasound monitoring recommended to assess follicle response, reduce multiple pregnancy risk.
PBS status
✘ Not PBS-listed (off-label for ovulation induction)
Clomiphene citrate
Clomid® · Serophene® · Selective oestrogen receptor modulator
Adult dose
50 mg PO daily for days 2–6 of cycle. Titrate to 100–150 mg if no ovulation.
Efficacy
Ovulation rate 70–80%; cumulative pregnancy rate 50% over 6 cycles. Live-birth rate lower than letrozole.
Side effects
Hot flushes, visual disturbances (discontinue immediately), mood changes, multiple pregnancy ~8%, anti-oestrogenic endometrial thinning with prolonged use (>6 cycles).
PBS status
⚠ PBS Restricted Benefit (for anovulatory subfertility)
Referral for IVF: If 6 cycles of letrozole or clomiphene (with documented ovulation) are unsuccessful, or if there are additional fertility factors (tubal disease, male factor, age >35), referral to a fertility specialist for gonadotrophin ovulation induction or IVF is recommended.
5. Endometrial Protection
Women with oligomenorrhoea or amenorrhoea not using COCP should achieve at least 4 withdrawal bleeds per year to reduce endometrial hyperplasia risk:
Medroxyprogesterone acetate
Provera® · Progesterone
Adult dose
10 mg PO daily for 10–14 days every 1–3 months (aim ≥4 bleeds/year)
PBS status
✔ PBS General Benefit
6. Intrauterine Device Option
Levonorgestrel intrauterine system (Mirena®) provides excellent endometrial protection and contraception without the systemic oestrogen exposure of COCP. Suitable for women with contraindications to oestrogen, obesity, or those who have completed fertility. Not recommended as first-line for hirsutism/acne management.
Special Populations
Pregnancy
COCP — contraindicated in pregnancy; must be ceased preconception.
Spironolactone — Category B3; teratogenic (feminisation of male fetus). Discontinue prior to conception or use reliable contraception.
Metformin — Category C. Some evidence supports continuation through pregnancy to reduce GDM and pre-eclampsia risk (PROBABLY trial data). Discuss with obstetric team.
Folic acid 5 mg daily (high-dose) recommended preconception and for first 12 weeks, given higher NTD risk in PCOS.
Screening: OGTT early in pregnancy (first trimester) and repeat at 24–28 weeks if initial normal.
Adolescents
Diagnosis: In adolescents, only 1 of 2 criteria required (oligomenorrhoea >2 years post-menarche + hyperandrogenism). PCOM on ultrasound is unreliable in adolescents due to physiologically high follicle counts.
COCP is first-line for menstrual regulation and hyperandrogenism.
Lifestyle counselling is critical, as adolescent behaviours set long-term trajectories.
Avoid metformin as first-line in adolescents unless significant IGT/T2DM or contraindication to COCP.
Perimenopause & Menopause
PCOS does not resolve at menopause. Metabolic risk persists and may worsen.
Continue OGTT and lipid screening. Cardiovascular risk monitoring becomes even more important.
Hormone replacement therapy (HRT) with oestradiol + progesterone may be considered for vasomotor symptoms; continuous combined HRT provides endometrial protection.
Co-morbid metabolic syndrome management (metformin, statins, antihypertensives) should follow standard guidelines.
Renal Impairment
Metformin: Contraindicated if eGFR <30; dose reduction at eGFR 30–45 (max 500 mg BD); do not initiate if eGFR <45.
Spironolactone: Increased hyperkalaemia risk. Monitor U&E closely. Avoid if eGFR <30.
Hepatic Impairment
COCP contraindicated in active liver disease, hepatic adenoma, or severe cirrhosis.
Metformin: Generally avoided in significant hepatic impairment due to lactic acidosis risk.
NAFLD screening (LFTs, hepatic ultrasound) recommended as PCOS is an independent risk factor.
Obesity & Bariatric Considerations
BMI >35 with significant metabolic comorbidity: Consider bariatric surgery referral. Weight loss of 15–25% post-bariatric surgery normalises ovulation in 50–80% and may resolve PCOS features.
BMI >40: COCP efficacy may be reduced; consider higher-dose preparations or alternative contraception (IUD).
GLP-1 receptor agonists (e.g., semaglutide — not PBS-listed for PCOS) show emerging efficacy in PCOS for weight loss and metabolic improvement. Off-label use requires specialist supervision.
Aboriginal and Torres Strait Islander Health Considerations
Aboriginal and Torres Strait Islander Health
📚 References
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