Primary amenorrhea

• Facts:
  Either from hypothalamic/pituitary abnormalities (central) or gonadal (peripheral) abnormalities
  
  Distinguish by measuring FSH
• Diagnosis:
  Increased FSH (peripheral cause)
  Karyotyping
  
  Decreased FSH (central cause)
  Order GnRH stimulation test
  
  Normal FSH
  Diagnosis of ovarian dysgenesis/agenesis
  
• Notes:
  Measurement of LH has no diagnostic value
• Associated With:
  Turner's syndrome (most common cause)