Partial gonadotrophin deficiency is infrequent in infertile men.

Hormone values and semen analyses were studied in 1761 men referred for evaluation of infertility to determine the frequency of isolated deficiency of either FSH, LH, or partial deficiency of both gonadotrophins. There were 17 men (1%) with oligospermia and FSH values at the lower end of the normal range. Without treatment, four pregnancies occurred in this group. Of the remainder, one was treated with gonadotrophin replacement therapy with no improvement in sperm concentration or motility. One man had possible isolated LH deficiency, but was subsequently found to have normal LH and testosterone values. No case of partial gonadotrophin deficiency was found. It was concluded that isolated deficiency of either FSH, LH, or partial deficiency of both gonadotrophins must be extremely rare as a cause of infertility.