Prolactin is a hormone that is secreted by both men and women. It is released by your pituitary gland, an organ responsible for regulating many of your body's functions, including reproduction. The pituitary gland is a small, bean-shaped organ located in the middle of your brain. Your pituitary gland releases prolactin on a daily basis, both in the morning and throughout the night. Certain activities like sexual intercourse and exercise also cause your pituitary gland to release prolactin Effects on Male Fertility Like prolactin infertility in women, prolactin can also affect male fertility....

Over their lifetimes, approximately one in every five couples in the United States seeks infertility care. Surprisingly, only half of couples who are trying to become pregnant achieve pregnancy easily and about one in ten American couples of reproductive age are involuntary infertile; male infertility accounts for half of these cases. Despite the relative importance of infertility due to the male, infertility evaluations have traditionally focused on women, because women tend to seek gynecological care and because men often are reluctant to seek advice."