Men may also have a biological clock, according to a new study. Groundbreaking new research shows that sperm quality apparently declines as males get older.
“We thought that men make sperm every 80 days, or every three months, no matter what their chronological age, the sperm were just brand new — hot off the press, if you will,” said Dr. William Schoolcraft, medical director of the Colorado Center for Reproductive Medicine, where the study was conducted. “Now it’s looking like at middle age, around 40 or 50, that the capacity for men to make sperm declines, at least in terms of quality.”
The study profiled male mice in different stages of their life cycle as they were mated with young female mice. When the male mice reached the human equivalent of 50 years of age, fertility issues began to arise with both natural conception and in vitro fertilization.
“When we took the sperm and made embryos, like a test-tube baby, we saw the embryos weren’t as healthy. They grew slower (and) they had fewer cells,” Schoolcraft said. “Then we found when we put those embryos in and there was a pregnancy, the miscarriage rate was much higher.”
Only 50 percent of the female mice mated with the older male mice became pregnant within a year’s time. Results of the research give credence to the theory that both men and women’s biological clocks are ticking.
“The eggs and the sperm still have their biological clock and if you wait, you can miss it,” Schoolcraft said. “It tells us to take our blinders off and not to think just about the female.”
The study should cause men to consider freezing their sperm if they think they may want to father children in their older years, said Dr. Schoolcraft.
"In a perfect world it would be nice for men to conceive before age 40, but I think after 50 their concern about age becomes more significant," he said.