Sperm quality declines sharply when men reach mid-thirties

The ticking of the biological clock may be as much of an issue for men in their mid-thirties as it is for women.

The ticking of the biological clock may be as much of an issue for men in their mid-thirties as it is for women.

Men as young as 35 can begin experiencing a drop in fertility due to declining sperm quality, according to an American study released today.

A team of scientists from the University of Washington found that genetic damage to sperm routinely starts to cause infertility in men aged 35 and over. The researchers, led by Narendra Singh, examined the sperm of 60 men with healthy sperm counts whose ages ranged from 22 to 60.

They found that the genetic quality of the sperm was closely linked to age. The results, released to the American Society for Reproductive Med-icine's conference at Seattle, show that sperm of men who were in the older age bracket was able to swim less vigorously than that of their younger counterparts.

The older men were also found to have higher concentrations of sperm with broken strands of DNA and higher levels of genetic damage. Their immune systems were less robust at defending the body against faulty sperm by a process of programmed cell suicide called apoptosis.

Researchers distinguished a point at which serious damage to the quality of sperm began to take effect at around 35. But the findings do not suggest that most men who want to try for children after the age of 35 will have problems.

William Keye, president of the American Society for Reproductive Medicine, said men who want to become fathers later in life could help themselves by maintaining a healthy lifestyle and avoiding activities such as smoking, which may damage the sperm's DNA.

The British infertility charity, Child, hoped the findings would encourage scrutiny of male infertility, which accounts for around a third of all infertility problems.