What blood workup and management are recommended for a patient diagnosed with Polycystic Ovary Syndrome (PCOS) on ultrasound?

Blood Workup and Management for PCOS Diagnosed on Ultrasound

For patients with PCOS identified on ultrasound, a comprehensive laboratory workup should include total testosterone, free testosterone, TSH, prolactin, fasting glucose/insulin ratio, 2-hour 75g OGTT, and lipid profile, with management focused on combined oral contraceptives and metformin regardless of BMI. 1

Diagnostic Considerations

It's important to note that ultrasound findings alone are insufficient for PCOS diagnosis. The Rotterdam criteria require at least two of three features:

• Chronic anovulation (irregular menstrual cycles)
• Hyperandrogenism (clinical or biochemical)
• Polycystic ovaries on ultrasound 1, 2

Ultrasound Criteria for PCOS

• ≥20 follicles (2-9mm) per ovary or ovarian volume ≥10ml 1
• Transvaginal approach is preferred if sexually active and acceptable to the patient 3
• For older ultrasound technology, ovarian volume ≥10ml is the threshold 3

Recommended Blood Workup

First-Line Laboratory Tests

• Androgen Assessment:
  • Total testosterone and free testosterone using mass spectrometry (highest diagnostic accuracy) 1
  • Free Androgen Index (FAI) - 78% sensitivity, 85% specificity 1
  • Androstenedione - 75% sensitivity, 71% specificity 1
  • DHEAS - 75% sensitivity, 67% specificity 1

Exclusion of Other Disorders

• TSH (thyroid disorders)
• Prolactin (hyperprolactinemia)
• 17-hydroxyprogesterone (congenital adrenal hyperplasia)
• Consider overnight dexamethasone suppression test or 24-hour urinary free cortisol (Cushing's syndrome) 1

Metabolic Assessment

• Fasting glucose/insulin ratio
• 2-hour 75g oral glucose tolerance test (OGTT) - especially for BMI >25 kg/m²
• Fasting lipid profile 1
• HbA1c (marker of cardiovascular risk) 4

Management Approach

First-Line Treatments

1. Oral Contraceptives:

   • Primary treatment for menstrual irregularities and hyperandrogenism
   • Regulates cycles, prevents endometrial hyperplasia
   • Lowers androgens and increases sex hormone-binding globulin 1
   • Note: May be associated with minor weight gain 4

2. Metformin:

   • Improves insulin sensitivity and reduces androgen levels
   • Associated with minor but significant weight loss regardless of BMI 4
   • Consider for all PCOS patients, including normal weight 4

3. Combined Approach:

   • Consider combined metformin and oral contraceptives for optimal management 4

4. Lifestyle Modifications:

   • Low glycemic index diet
   • Regular physical activity
   • Weight loss if overweight/obese 1

Special Considerations

Pitfalls to Avoid

• Using inappropriate testosterone assays (direct immunoassays) instead of mass spectrometry 1
• Relying solely on ultrasound for diagnosis 1
• Using LH/FSH ratio as diagnostic criterion (low sensitivity at 41-44%) 5
• Failing to screen for metabolic complications 1

Age-Specific Considerations

• Ultrasound should not be used for PCOS diagnosis in those <8 years after menarche due to high incidence of multi-follicular ovaries 3
• Diagnostic thresholds should be revised regularly with advancing ultrasound technology 3

Monitoring and Follow-up

• Regular assessment of metabolic parameters (glucose, lipids, blood pressure)
• Monitoring for endometrial hyperplasia in untreated patients with irregular cycles
• Evaluation of treatment efficacy for symptom control
• Screening for cardiovascular risk factors

By following this evidence-based approach to blood workup and management, clinicians can effectively diagnose and treat patients with PCOS identified on ultrasound, potentially improving both short-term symptoms and long-term health outcomes.