On playgrounds across the country, it's getting tougher to tell who's watching the kids -- dad or granddad. Experts predict the trend of older fathers will continue creeping upward. Why the rise and, more importantly, at what cost?
"The women set the baby-making agenda," says Harry Fisch, MD, director of the Male Reproductive Center at Columbia-Presbyterian Medical Center in New York and author of The Male Biological Clock: the Startling News about Aging and Fertility in Men. As more and more women wait to have children, their spouses are forced to postpone parenthood, too. Back in 1970, less than 15% of all men fathering children were over 35. Today, that percentage has risen to almost one-quarter. Even among men in the 50 to 54 age group, there's been a notable increase in fatherhood.
If it takes just one sperm and one egg to create a baby, why must men make so many sperm? And how many sperm are considered normal? How long do sperm live? Can they survive outside the body? Do men stop making sperm as they age? Is there anything you can do to increase sperm production or improve the health of your sperm?
WebMD takes a look at the facts about sperm and answers these and other frequently asked questions.
While it has become more socially acceptable to put off fatherhood, experts caution that the decision is not without risks.
"The role of the male in infertility has been grossly overlooked by lay and professionals alike," says Peter Schlegel, MD, urologist-in-chief at New York-Presbyterian Hospital/ Weill Cornell Medical Center, and president of the Society for Male Reproduction and Urology.
Effects of Age on Male Fertility
Whereas most women realize that their biological clock ticks as they age, the same cannot be said for men. "Not only are men not aware of the impact their age has on infertility, they deny it. They walk around like they're 18 years old," Fisch tells WebMD. It's no wonder.
Until recently, popular belief held that men could father children as easily at 78 as they could at 18. But a mounting body of evidence is showing otherwise.
In one study of couples undergoing high-tech infertility treatments, researchers concluded that a man's chances of fathering a child decrease with each passing year. In the study, the odds of a successful pregnancy fell by 11% every year; their chances for obtaining a successful live birth declined even farther. The study was reported in a 2004 issue of the American Journal of Gynecology.
As sure as men age, so too do their sperm. German researchers compiling the most recent data on aging sperm reported that the volume, motility (ability to move toward its destination, an awaiting egg), and structure of sperm all decline with age. They published this update in a 2004 issue of Human Reproduction Update.