Male Biological Clock Is Very Real

Tuesday, 15 October, 2002, 07:44 GMT 08:44 UK
Male biological clock is ticking

Sperm cells accumulate damage over time
The chances of a man having children dip past his 35th birthday, researchers have found.
The researchers, from the University of Washington in Seattle, found that damage to the genetic material containing sperm cells increases with age.
We found there is a significant change by the age of 35
Dr Narendra SinghUnlike most other cells in the body, sperm cells are unable to repair this damage.
In addition, the researchers found that as a man gets older he loses his natural ability to weed out unhealthy sperm cells through a process known as apoptosis.
This means that there is a greater chance that a damaged sperm cell will successfully fertilise the female egg.
This could mean that the risk of miscarriage is increased or, at the other end of the scale, that children have a greater chance of developing mild abnormalities such as uneven teeth, or asymmetrical limbs.
Lead researcher Dr Narendra Singh told the BBC: "We found there is a significant change by the age of 35."
Sperm quality
Dr Singh's team examined sperm quality in 60 men aged between 22 and 60. All had healthy sperm counts.
The researchers found that men aged 35 and older had higher concentrations of sperm with broken strands of DNA, and that the damage was greater.