Male biological clock

In recent years, experts have been trying to warn women that their fertility drops off dramatically starting in their 30's.  But now there is 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 doctor Joan Stoler at Massachusetts general hospital say  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.

"One can presume there could be new mutations or changes in the geners that could cause various diseases  but it's a big step to go from abnormal dna in sperm to what actually gets fertilized."

As more and more couples wait to have children later in life, experts hope that more men will consider how these new findings could effect the health of their children.

"It's just a step toward cooroborating what we've suspected or known for a long time that there are risks associated with advanced paternal age.  It is 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 and d octors say smoking and heavy drinking can also affect a man's fertility.