Polycystic ovary syndrome in adolescents — formative SAQs

SAQ 1 — Diagnostic approach to suspected PCOS (10 marks)

A 16-year-old presents with irregular periods (cycles 40–60 days), moderate acne, and a Ferriman-Gallwey score of 8. Menarche was at age 12. Her mother has type 2 diabetes. A pelvic ultrasound reports "polycystic ovaries." The GP has told the family she has PCOS. [2] [4]

Questions

1. State the Rotterdam diagnostic criteria and explain why adolescent-specific modification is required. (4 marks) [4] [2]
2. List the investigations needed to confirm the diagnosis and exclude mimics, with one sentence of justification for each. (4 marks) [3] [1]
3. Explain whether the ultrasound finding alone establishes the diagnosis in this adolescent. (2 marks) [2] [1]

Model answer

Rotterdam criteria and adolescent modification (4). Rotterdam requires two of three: oligo-/anovulation, clinical or biochemical hyperandrogenism, and polycystic ovarian morphology on ultrasound, after exclusion of mimics. Adolescent modification: do not diagnose on ultrasound alone because multifollicular ovaries are physiologically normal in teens; require persistence of ovulatory dysfunction beyond two years post-menarche and objective hyperandrogenism before applying the label. This patient is four years post-menarche, so persistence is met. [4] [2]

Investigations (4). Total and calculated free testosterone or free androgen index to document biochemical hyperandrogenism (SHBG is suppressed by insulin, so free testosterone is more sensitive than total). TSH to exclude thyroid dysfunction as a cause of menstrual irregularity. Prolactin to exclude hyperprolactinaemia. 17-hydroxyprogesterone to exclude non-classic congenital adrenal hyperplasia — the most important mimic. Fasting glucose or HbA1c and a lipid panel for metabolic screening; consider OGTT if BMI is elevated. [3] [1]

Ultrasound alone (2). The ultrasound finding does not establish the diagnosis. Up to 30–40% of healthy adolescent ovaries meet adult PCOM criteria. The Pena 2025 adolescent recommendations and Rosenfield 2015 statement both caution against ultrasound-based diagnosis in this age group. The diagnosis requires persistent menstrual dysfunction and objective hyperandrogenism, both of which this patient may have, but the ultrasound is supportive rather than diagnostic. [2] [1]

SAQ 2 — Management and long-term care (10 marks)

A 15-year-old is diagnosed with PCOS (phenotype A: oligo-ovulation, biochemical hyperandrogenism, PCOM). BMI is 31. She has moderate acne and irregular cycles. She discloses low mood and body image distress in private. [5] [7]

Questions

1. Outline the stepwise management plan, starting with the foundation treatment. (5 marks) [5] [3]
2. Justify the role of metformin versus the combined oral contraceptive pill in this patient, citing evidence. (3 marks) [6] [3]
3. Describe the metabolic and mental health screening plan for follow-up. (2 marks) [8] [7]

Model answer

Stepwise management (5). Step 1: Lifestyle modification is first-line for every patient — exercise 150+ minutes per week, sleep optimisation, healthy eating pattern targeting 5–10% weight reduction, framed around health behaviours not weight to avoid triggering disordered eating. Step 2: Combined oral contraceptive pill for menstrual regulation, endometrial protection, and mild antiandrogen effect to address acne. Step 3: If hirsutism or acne persist after six months of COCP, add spironolactone with reliable contraception counselling due to teratogenicity. Step 4: Screen and address mental health — the patient has disclosed low mood and body image distress; a PHQ-9 or equivalent screen and a clear pathway to psychology are part of core management, not optional add-on. Step 5: Follow-up every 3–6 months initially with menstrual, metabolic and mental health review. [5] [3] [7]

Metformin versus COCP (3). The COCP is first-line for menstrual regulation and endometrial protection in this patient; it also raises SHBG and reduces free testosterone, addressing her acne. Metformin is an adjunct, not a substitute. The Hoeger randomised trial in obese adolescent women showed metformin plus lifestyle modestly improved menstrual cyclicity and insulin sensitivity beyond lifestyle alone, but the effect is adjunctive. Metformin is most useful for metabolic dysfunction (impaired glucose tolerance, significant insulin resistance), which this obese patient may have. It does not reliably treat hirsutism or provide endometrial protection. [6] [3]

Follow-up screening (2). Metabolic: annual fasting glucose or HbA1c, lipid panel, blood pressure, and ALT for NAFLD screening; OGTT if BMI remains elevated or risk factors progress. Mental health: screen for anxiety and depression at every visit using PHQ-9 or equivalent, because up to 50% of women with PCOS experience these and untreated mental health worsens every other outcome. [8] [7]