عنوان مقاله [English]
نویسنده [English]چکیده [English]
Reproduction is the biological process by which a new individual organism is produced from their parents (sexual method) or parent (asexual method), and is essential for the survival of species. Nowadays, global trends in total fertility rate (TFR) show 2-fold decrease compared to 1950-1955. The average number of children per woman over her reproductive life subject for ages 15-49 was estimated to be 4.96 in 1950-1955 and 2.52 in 2010-2015. The present paper reviews hormonal regulation of spermatogenesis and sperm maturation in men, and investigates the roles of men in global rate of couple infertility. This study shows that decrease in TFR is associated with an increase in number of men that produce semen under the World Health Organization reference values, and considered as infertile men. Comprehensive analyses of world map on TFR, poverty (percentage of population living on less than $1.25 per day), and hunger (percentage of population suffering from hunger) show that TFR has highly decreased in populations inhabiting the area under poverty and hunger; associated with an increase in number of infertile men. Considering a cross-talk between reproduction and metabolism, the present study suggests that suffering from hunger is a key determinant to decrease TFR due to disruption of hormonal regulation of spermatogenesis and sperm maturation in men.