Abstract
The thyroid is the largest endocrine gland in the body. The thyroid hormones play an important role in many metabolic processes. Thyroid diseaseis the most common endocrine disease affecting women of reproductive age. Change sinthyroidfunction adversely affect female reproductive healthbefore, during and after conception. In addition, thyroid disease has long been considered a risk factor for miscarriage and may adversely affect perinatal outcome and mortality. Therefore, the author recently mentioned screening for thyroid disease in women with reproductive problems, recurrent miscarriages at the onset ofpregnancy. Incontrast to that, the effects of thyroid hormones on male reproductive function are largely unknown andrarely mentioned. The relationship between thyroid function and spermatogenesis in adult men and the way thyroid hormones affect testicular function remains controversial. There have been a few studies showing negative effects of hyperthyroidism and hypothyroidism on semen parameters. Hyperthyroidism has been found to be inversely related to sperm count and motility. Hypothyroidism has a negative effect on sperm motility, sperm morphology and semenvolume.