What are the diagnostic criteria for Polycystic Ovary Syndrome (PCOS)?

Diagnostic Criteria for Polycystic Ovary Syndrome (PCOS)

According to the Rotterdam criteria, PCOS is diagnosed when at least two of the following three features are present: oligo- or anovulation, clinical and/or biochemical signs of hyperandrogenism, and polycystic ovaries on ultrasound, after exclusion of other relevant disorders. 1

Core Diagnostic Criteria

1. Oligo- or Anovulation

   • Manifests as menstrual cycle anomalies
   • Includes amenorrhea, oligomenorrhea (cycles >35 days), or long cycles
   • Can be assessed through menstrual history

2. Hyperandrogenism

   • Clinical signs:
     • Hirsutism (excessive hair growth in male pattern distribution)
     • Acne
     • Male pattern hair loss
   • Biochemical signs:
     • Elevated total or free testosterone
     • Elevated androstenedione
     • Elevated DHEAS

3. Polycystic Ovarian Morphology (PCOM) on Ultrasound

   • Presence of at least 12 follicles in each ovary measuring 2-9 mm in diameter, and/or
   • Increased ovarian volume >10 ml 2
   • FNPO (follicle number per ovary) has the highest diagnostic accuracy with sensitivity of 84.32% and specificity of 91.06% 1

Important Exclusions

Before confirming PCOS diagnosis, other disorders with similar presentations must be ruled out:

• Thyroid dysfunction
• Hyperprolactinemia
• Congenital adrenal hyperplasia
• Cushing's syndrome
• Androgen-secreting tumors
• Idiopathic hirsutism

Special Considerations

Adolescents

• Ultrasound is not recommended for PCOS diagnosis within 8 years of menarche 1
• Diagnosis should rely more on clinical and biochemical hyperandrogenism and menstrual irregularities
• Multi-follicular appearance on ultrasound can overlap with PCOM diagnostic cutoffs in adolescents 1

Older Women

• PCOM cutoff values might be considerably lower in older women with PCOS 1
• Age-specific criteria may be needed for accurate diagnosis

Diagnostic Challenges and Pitfalls

1. Ultrasound Limitations

   • Operator and equipment dependent
   • Transabdominal vs. transvaginal approach affects accuracy
   • Equipment advances increase sensitivity and follicle counts 1
   • Consider ovarian volume (OV) as an alternative when accurate follicle counts are not possible 1

2. Anti-Müllerian Hormone (AMH)

   • Proposed as a potential alternative to ultrasound for PCOM detection
   • Higher in women with PCOS compared to normal ovulatory women
   • Currently lacks standardized cutoffs and validation for routine clinical use 1
   • May replace ultrasound in PCOS diagnosis once standardization issues are addressed

3. Phenotypic Variations

   • The Rotterdam criteria create additional phenotypes compared to older NIH criteria:
     • Women with hyperandrogenism and polycystic ovaries but normal ovulation
     • Women with ovulatory dysfunction and polycystic ovaries but no hyperandrogenism
   • These phenotypes may have different metabolic and reproductive risks 3, 4

Recommended Metabolic Screening

Once PCOS is diagnosed, systematic screening for metabolic abnormalities should include:

• Weight, height, BMI calculation
• Waist circumference measurement
• Blood pressure
• Laboratory parameters:
  • Fasting plasma glucose
  • Triglycerides
  • HDL cholesterol 2
• Oral glucose tolerance test (OGTT) for patients with BMI >30 kg/m² and normal fasting glucose 2

Diagnostic Algorithm

1. Initial Assessment:

   • Document menstrual pattern (frequency, regularity)
   • Assess for clinical signs of hyperandrogenism
   • Measure serum androgens (total/free testosterone)

2. If one criterion is present:

   • Proceed to transvaginal ultrasound (if >8 years post-menarche)
   • Assess ovarian morphology using standardized criteria

3. If two criteria are present:

   • Proceed to exclusion of other disorders
   • Thyroid function tests, prolactin, 17-hydroxyprogesterone

4. If other disorders excluded and two criteria confirmed:

   • Diagnose PCOS
   • Proceed to metabolic screening
   • Initiate appropriate management

By following these diagnostic criteria systematically, clinicians can accurately diagnose PCOS and initiate appropriate management to address both reproductive and metabolic aspects of the syndrome.