Infertility is the inability to achieve pregnancy after a whole year of unprotected sexual intercourse and without the use of birth control measures. For a man to be fertile, his reproductive function must be intact. This means that he must be able to produce sufficient sperms, which should be well nourished, and move freely through tubes and other genital organs to reach the penis during ejaculation. This entire process also requires healthy function of his reproductive hormone, testosterone.
Male reproductive issues account for a third of infertility, female reproductive issues account for another third while combined male-female reproductive issues account for the remaining third. The take-home here is that male infertility is as common as female infertility.