12/06/02 - Male Biological Clock

We've known for years that a woman's advancing age can adversely affect her fertility and her chances of having a healthy baby. But now researchers say there's new evidence that men may also have a so-called "biological clock." Researchers found the DNA in sperm decline after age 35, proving that women aren't the only ones who's clocks are ticking.
In recent years, experts have been trying to warn women that their fertility drops off dramatically starting in their 30's. But now there's growing evidence that a man's age may also affect his ability to have a healthy child.
Researchers in Washington recently reported that sperm cells of men over 35 show more DNA damage than the sperm of younger males. But they're still not sure whether or not that damaged DNA could be transmitted to a baby and if so, what health consequences it could have. Dr. Joan Stoler at Massachusetts General Hospital says, "One can presume there could be new mutations or changes in the genes that could cause various diseases, but it's a big step to go from abnormal DNA in sperm to what actually gets fertilized." But as more and more couples wait to have children later in life, experts hope that more men will consider how these new findings could affect the health of their children. "It's just a step toward collaborating what we've suspected or known for a long time that there are risks associated with advanced paternal age," Dr. Stoler says. "It's something fathers who are getting on in years should note also." Researchers say further studies need to be done to determine exactly what effects a man's damaged sperm may have on his offspring.
In the meantime, there are other factors within a man's control that can affect his fertility, like smoking and heavy drinking, which research has already shown can be damaging to sperm.