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 a patient suspected of having PCOS should include a comprehensive history, physical examination, laboratory testing, and appropriate imaging to confirm the diagnosis based on Rotterdam criteria (at least two of three: oligo/anovulation, hyperandrogenism, and polycystic ovaries) while excluding other causes of androgen excess.

Clinical History Assessment

• Obtain detailed information about menstrual history, including cycle length, regularity, and amenorrhea (cycle length >35 days suggests chronic anovulation) 1
• Document onset and duration of signs of androgen excess (gradual onset suggests PCOS; rapid onset suggests androgen-secreting tumor) 1, 2
• Review medication use, particularly exogenous androgens 1
• Assess lifestyle factors including diet, exercise, alcohol use, and smoking 1
• Obtain family history of cardiovascular disease and diabetes 1

Physical Examination

• Evaluate for clinical signs of hyperandrogenism:
  • Hirsutism (distribution of body hair) 1
  • Acne (severe or treatment-resistant acne may indicate PCOS) 1, 2
  • Alopecia (typically vertex, crown, or diffuse pattern) 1, 2
  • Clitoromegaly (suggests more severe hyperandrogenism) 1
• Assess for signs of insulin resistance:
  • Obesity (calculate BMI and waist-hip ratio) 1
  • Acanthosis nigricans (dark, velvety skin in body folds) 1
• Perform pelvic examination to evaluate for ovarian enlargement 1
• Screen for signs of Cushing's syndrome (buffalo hump, moon facies, abdominal striae, etc.) 1

Laboratory Testing

• Hormonal evaluation:

  • Total testosterone or bioavailable/free testosterone (preferably using equilibrium dialysis techniques) 1, 2
  • Sex hormone-binding globulin (SHBG) 1
  • Thyroid-stimulating hormone (TSH) to rule out thyroid disease 1
  • Prolactin level to exclude hyperprolactinemia 1, 3
  • 17-hydroxyprogesterone to rule out non-classic congenital adrenal hyperplasia 1, 3

• Metabolic evaluation:

  • Two-hour oral glucose tolerance test with 75g glucose load (all women with PCOS should be screened for diabetes) 1
  • Fasting lipid profile (total cholesterol, LDL, HDL, triglycerides) 1

Imaging Studies

• Transvaginal ultrasound (preferred approach if sexually active and acceptable to the patient) 1:

  • Using 8MHz or higher transducer, look for ≥20 follicles (2-9mm) per ovary 1
  • Measure ovarian volume (≥10mL suggests PCOM) 1
  • Document three dimensions of each ovary 1
  • Note: Ultrasound is not recommended for diagnosis in adolescents <8 years post-menarche due to high incidence of multi-follicular ovaries 1

• Transabdominal ultrasound (alternative if transvaginal approach not possible):

  • Focus on ovarian volume with threshold of ≥10mL 1
  • Less reliable for accurate follicle counting 1

• MRI pelvis (without contrast):

  • Consider only when ovaries cannot be adequately visualized by ultrasound 1
  • Particularly useful in obese adolescents 1

Differential Diagnosis Considerations

• Rule out other causes of androgen excess 1:
  • Cushing's syndrome (consider overnight dexamethasone suppression test) 1, 3
  • Androgen-secreting tumors (ovarian or adrenal) 1
  • Non-classic congenital adrenal hyperplasia 1, 3
  • Acromegaly 1
  • Primary ovarian failure 1
  • Hyperprolactinemia 1, 3

Important Clinical Pitfalls

• Serum AMH levels should not yet be used as a single test for PCOS diagnosis despite emerging evidence 1
• Diagnosis in adolescents requires special consideration - should meet all three Rotterdam criteria and be at least 2 years post-menarche 2, 4
• Rapid onset of virilization symptoms requires immediate evaluation for androgen-secreting tumors 4
• Ultrasound findings alone are insufficient for diagnosis as PCOM may be present in up to one-third of reproductive-aged women 1
• Increased risk of endometrial cancer with chronic anovulation requires appropriate follow-up 1, 5