Polycystic ovary syndrome (PCOS) — Frequently asked questions (FAQ)
1) What does this algorithm cover?
The algorithm guides the structured clinical approach to PCOS, from initial suspicion and application of the Rotterdam criteria to the exclusion of alternative diagnoses. It integrates screening for metabolic comorbidities — blood pressure, lipid profile and glucose assessment — and organises treatment according to reproductive goals — whether or not the patient wishes to become pregnant — and predominant manifestations, such as menstrual irregularity/anovulation, hyperandrogenism and cardiometabolic risk.
2) When should PCOS be suspected?
PCOS should be suspected in the presence of irregular cycles — oligomenorrhoea/amenorrhoea —, infertility due to probable anovulation and/or signs of hyperandrogenism — hirsutism, persistent acne, androgenetic alopecia. PCOS may also be considered when polycystic ovarian morphology is found on ultrasound, especially if gynaecological or dermatological symptoms coexist. Presentation is heterogeneous and assessment should be adapted to age and clinical context.
3) How is the diagnosis confirmed in adults?
In adults, diagnosis is based on the Rotterdam criteria, requiring 2 out of 3 after exclusion of other causes: ovulatory dysfunction — oligo/amenorrhoea —, hyperandrogenism — clinical and/or biochemical — and polycystic ovarian morphology — PCOM. In practice, when menstrual irregularity and hyperandrogenism are both present, ultrasound/AMH is not required to confirm the diagnosis, provided mandatory exclusions have been ensured.
4) Which diagnoses should be excluded before confirming PCOS?
Before confirming PCOS, common causes of ovulatory dysfunction/hyperandrogenism should be excluded: pregnancy, thyroid dysfunction — TSH —, hyperprolactinaemia and non-classic congenital adrenal hyperplasia — 17-OH-progesterone. If red flags are present — rapid onset, virilisation, marked amenorrhoea, systemic signs —, targeted assessment for androgen-secreting tumour, Cushing syndrome, acromegaly, functional hypothalamic amenorrhoea or premature ovarian insufficiency should be considered.
5) How should adolescents with suspected PCOS be approached?
In adolescents, diagnosis should be more cautious to avoid overdiagnosis. In general, PCOS is considered when there is hyperandrogenism — clinical and/or biochemical — and persistent ovulatory dysfunction after the early post-menarche phase. Ultrasound and AMH should not be used as diagnostic criteria at this stage because of low specificity. Whenever there is uncertainty, follow-up and longitudinal reassessment are preferable.
6) Which metabolic assessment should be performed and why?
PCOS is associated with increased risk of insulin resistance, dyslipidaemia, hypertension and type 2 diabetes. Assessment of blood pressure, lipid profile and glucose is recommended — with an OGTT when indicated by risk. This assessment allows cardiometabolic risk stratification, early intervention and definition of the need for pharmacological therapy — for example metformin in the context of impaired glucose tolerance/type 2 diabetes.
7) What is the role of lifestyle modification?
Lifestyle modification is the foundation of PCOS treatment. In patients with excess weight, dietary intervention combined with regular physical activity is first line, and may improve menstrual cycles, ovulation, manifestations of hyperandrogenism and reduce cardiometabolic risk. Even modest weight loss may be associated with clinically relevant benefit, and the approach should be individualised and sustainable.
8) What should be done if the patient wishes to become pregnant?
In PCOS with infertility due to probable anovulation, first-line pharmacological treatment for ovulation induction is letrozole. Response should be monitored, preferably by confirming ovulation with progesterone in the luteal phase or, when available, with ultrasound monitoring. If ovulation does not occur, dose escalation within usual limits and reassessment may be required. If treatment failure occurs or other infertility factors coexist, referral to secondary care / medically assisted reproduction should be considered.
9) Is metformin indicated for infertility in PCOS?
Metformin may be considered as adjunctive treatment in infertility associated with PCOS, with potentially greater benefit in patients with obesity and/or insulin resistance or impaired glucose tolerance. However, it does not replace ovulation induction with letrozole as first-line treatment. The decision should integrate metabolic profile, tolerability and reproductive goals, avoiding overtreatment in patients without a metabolic indication.
10) If the patient does not wish to become pregnant, what is the first-line approach?
In patients who do not wish to become pregnant, combined hormonal contraception is often the first-line option for cycle regulation and control of hyperandrogenic manifestations. Formulations with anti-androgenic effect may be preferred when hirsutism/acne are relevant. When combined contraceptives are contraindicated, cyclic progestogen may be used for endometrial protection, without significant benefit for hirsutism/acne.
11) How should hirsutism and acne in PCOS be treated?
First-line treatment for hirsutism and acne in PCOS, when there is no pregnancy wish, is combined hormonal contraception. If response is insufficient, anti-androgens — for example spironolactone — may be considered, but only with effective contraception because of potential teratogenicity. Assessment of psychosocial impact and coordination with dermatology may be useful in moderate to severe or refractory cases.
12) When should reassessment and/or referral be considered?
Reassessment is needed if there is diagnostic uncertainty, red flags, rapid worsening of hyperandrogenism, or persistent symptoms despite appropriate treatment. In infertility, referral is appropriate when there is failure of ovulation induction, advanced maternal age, long duration of infertility or suspected male/tubal factors. During follow-up, it is important to monitor metabolic risk and adherence to lifestyle measures, adjusting the strategy over time.
