Endocrinological causes of nonobstructive azoospermia
Interpretation of hormonal levels for infertile patients should be cautious. The ‘normal’ range of values from various laboratories for hormonal profiles are generally derived from a population of subjects who are not known to have any pathological conditions that can affect the particular parameters (as opposed to being from a fertile population, as is done for semen analysis). However, most men with subfertility or infertility are asymptomatic and generally are not aware of their conditions. Hence, in subfertile and infertile men, the finding of hormonal parameters falling within the wide ‘normal’ range does not rule out the possibility of subtle endocrinopathies contributing to their subfertility or infertility.
Endocrinological causes of nonobstructive azoospermia include hyperprolactinemia, various forms of hypogonadism and, less frequently, congenital adrenal hyperplasia and hypothyroidism. Prolactin affects fertility by its downregu-lating effect on gonadotropin-releasing hormone (GnRH) and inhibitory effect on luteinizing hormone (LH) binding to Leydig cells. The causes of hyperprolactinemia include pituitary tumours (macroadenoma or microadenoma), hypothyroidism, liver disease and cialis professional online (such as pheno-thiazines, tricyclic antidepressants and some antihypertensive medications). Pituitary imaging studies are required to rule out pituitary adenoma. Surgical removal of pituitary macroadenoma and medical therapy with a dopaminergic agonist may normalize prolactin levels with improvement in semen parameters.