Women who put off motherhood until later in life often face decreased fertility with age. But now a bioethicist in Scotland is saying that men, too, who father children late in life might be putting the health of their kids at risk.

Dr. Kevin Smith of Abertay University in Dundee believes that sperm-freezing for all 18-year-olds should become a norm under Britain's National Health Service. The bioethicist argues that as men become older, their sperm are at a greater risk of resulting in disorders among offspring, including autism and schizophrenia.

Smith believes sperm-freezing will allow men to have children later in life with less risk of such disorders. Even though there is no fixed age for a man to become an "older father," there should be an option to turn to in a man's 40s, says Smith.

Smith's argument has received mixed reviews from the other experts. Allan Pace, an andrology professor at the University of Sheffield in England, believes this is one of the worst suggestions he's ever heard.

"We know that the sperm from the majority of men won't freeze very well, which is one of the reasons why sperm donors are in short supply," he explained. "Therefore, men who froze their sperm at 18, and returned to use it later in life, would essentially be asking their wives to undergo one or more IVF procedures in order to start a family."

Nevertheless, most scientists agree that age affects the quality of sperm, if not quantity. In addition, they believe that the quality has decreased significantly in the past 50 years. According to Niels Jorgensen from the University of Copenhagen, only 25 percent of men in Europe have good-quality sperm.

Jorgensen believes that the continuous decline in the quality of sperm may result in smaller families and difficulty in natural conception. In addition, he estimates that nearly 15 percent of men will have to resort to fertility treatments in future while planning to start a family.