Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (936 page)

   Diagnosis and management of infertility

   Interpretation

Increased In

   Primary hypogonadism (anorchia, testicular failure, menopause)

   Gonadotropin-secreting pituitary tumors

   Precocious puberty (secondary to a CNS lesion or idiopathic)

   Complete testicular feminization syndrome

   Luteal phase of menstrual cycle

Decreased In

   Secondary hypogonadism

   Kallmann syndrome (inherited X-linked or autosomal isolated deficiency of GnRH; occurs in both sexes) found in approximately 5% of patients with primary amenorrhea. Causes failure of both gametogenic function and sex steroid production (LH and FSH are “normal” or undetectable but rise in response to prolonged GnRH stimulation)

   Pituitary LH or FSH deficiency

   Gonadotropin deficiency

   Limitations

   Because of the episodic, circadian, and cyclic nature of its secretion, clinical evaluations may require determinations in pooled multiple serial specimens.