What is the initial workup for a patient suspected of having Polycystic Ovary Syndrome (PCOS)?

Initial Workup for Polycystic Ovary Syndrome (PCOS)

The initial workup for PCOS should include assessment of menstrual history, clinical signs of hyperandrogenism, laboratory testing for hormonal abnormalities, and transvaginal ultrasound to evaluate ovarian morphology, following the Rotterdam criteria requiring at least two of three key features: oligo/anovulation, hyperandrogenism, and polycystic ovarian morphology. 1

Clinical Assessment

History

• Menstrual history: Document cycle length (>35 days suggests chronic anovulation) 1
• Symptoms of hyperandrogenism: Onset and progression of hirsutism, acne, alopecia 1
• Family history: Cardiovascular disease, diabetes 2
• Lifestyle factors: Alcohol use, smoking 2

Physical Examination

• Signs of hyperandrogenism:
  • Hirsutism (excessive hair growth in male pattern distribution)
  • Acne
  • Androgenic alopecia (male pattern balding)
  • Clitoromegaly (rare) 2
• Metabolic assessment:
  • Body Mass Index (BMI)
  • Waist-hip ratio 2, 1
  • Acanthosis nigricans (velvety, hyperpigmented skin in body folds - sign of insulin resistance) 2
• Pelvic examination to assess ovarian enlargement 2

Laboratory Testing

First-line Tests

• Total testosterone and free testosterone (preferably using liquid chromatography-tandem mass spectrometry) 1
  • Free testosterone can be measured by equilibrium dialysis or calculated using free androgen index (FAI) 1
• Thyroid-stimulating hormone (TSH) to exclude thyroid disorders 2, 1
• Prolactin level to exclude hyperprolactinemia 2, 1
• Two-hour oral glucose tolerance test with 75g glucose load (to assess for diabetes/insulin resistance) 2, 1
• Fasting lipid profile (total cholesterol, LDL, HDL, triglycerides) 2, 1

Additional Tests (as indicated)

• DHEAS and androstenedione (if androgen-secreting tumor suspected) 1
• 17-hydroxyprogesterone (to rule out non-classic congenital adrenal hyperplasia) 1, 3
• Anti-Müllerian hormone (can be useful for diagnosis) 1
• Screening for Cushing's syndrome if clinical signs present (buffalo hump, moon facies, abdominal striae, etc.) 2

Imaging

• Transvaginal ultrasound (preferred method for women who are sexually active) 1
  • Diagnostic criteria for polycystic ovarian morphology (PCOM):
    • ≥20 follicles per ovary measuring 2-9mm and/or
    • Ovarian volume ≥10ml 1
  • Should be performed with ≥8MHz transducer 1
• MRI of the pelvis without contrast (alternative for patients who cannot tolerate transvaginal ultrasound, particularly useful in obese patients) 1

Diagnostic Criteria

PCOS diagnosis requires at least two of the following three Rotterdam criteria:

1. Oligo/anovulation
2. Clinical or biochemical hyperandrogenism
3. Polycystic ovarian morphology on ultrasound 1, 4

Differential Diagnosis

Rule out other causes of hyperandrogenism and menstrual irregularities:

• Cushing's syndrome
• Androgen-secreting tumors (ovarian or adrenal)
• Non-classic congenital adrenal hyperplasia
• Exogenous androgens
• Acromegaly
• Thyroid disorders
• Primary ovarian failure
• Hyperprolactinemia 2, 1

Important Considerations

• Clearly document the patient's PCOS phenotype (there are four recognized phenotypes with different long-term health implications) 4
• Recognize that PCOS is associated with increased risk for:
  • Type 2 diabetes and glucose intolerance
  • Cardiovascular disease (hypertension, dyslipidemia)
  • Endometrial cancer
  • Psychological disorders (anxiety, depression) 1, 4
• In adolescents, diagnosis is particularly challenging as many PCOS features overlap with normal puberty 3
  • Persistent oligomenorrhea 2-3 years post-menarche suggests underlying ovarian or adrenal dysfunction
  • Ultrasound is not recommended as first-line investigation in girls <17 years 3

Following this systematic approach ensures comprehensive evaluation of patients with suspected PCOS, allowing for appropriate diagnosis and management of this common endocrine disorder.