Endocrine testing

The endocrine assessment of a man with fertility problems or a low sperm count includes measurements of serum total testosterone, LH, and FSH and other tests as clinically indicated. Serum total testosterone should be measured on a blood sample obtained between 8 and 10 AM.

The results may indicate a number of different diagnoses such as:

  • Primary (hypergonadotropic) hypogonadism (affecting both spermatogenesis and Leydig cell function).
  • Primary (hypergonadotropic) hypogonadism (seminiferous tubule damage without Leydig cell dysfunction).
  • Secondary (hypogonadotropic) hypogonadism.
  • Partial androgen resistance.  

Medical therapies to increase circulating gonadotropin concentrations 

Therapies to increase circulating gonadotropins (and maximally stimulate spermatogenesis) include clomiphene citrate, aromatase inhibitors and recombinant human follicle-stimulating hormone (rhFSH).