Study: Sperm Quality Gradually Declines as Men Get Older

[Soontir C'boath]

Study: sperm quality declines with age

By RANDOLPH E. SCHMID, AP Science WriterMon Jun 5, 5:04 PM ET

It isn't only women who face a ticking biological clock when planning parenthood.

New research has found that as men age, the quality of their sperm deteriorates, making it more likely they will have trouble becoming fathers and increasing the possibility of having a child with dwarfism.

The study, led by Andrew Wyrobek of Lawrence Livermore National Laboratory and Brenda Eskenazi of the University of California, Berkeley, School of Public Health, appears in this week's online edition of the Proceedings of the National Academy of Sciences.

Women's biological time clock has long been known, with older women having an increased risk of miscarriage and of producing children with genetic defects such as Down Syndrome.

"Our research suggests that men, too, have a biological time clock — only it is different," Eskenazi said in a statement. "Men seem to have a gradual rather than an abrupt change in fertility and in the potential ability to produce viable, healthy offspring."

Both men and women have been postponing parenthood in recent years. Since 1980, the researchers said, birth rates have increased 40 percent for men aged 35 to 49, while there has been a decline in births involving men under 30.

The same team had previously found that as men age their sperm count declines and their sperm becomes less active.

The new report looked at 97 men aged 22 to 80 and found increased fragmentation of the DNA in sperm as men age.

"This study shows that men who wait until they're older to have children are not only risking difficulties conceiving, they could also be increasing the risk of having children with genetic problems," said Wyrobek.

Unlike older women, the changes in sperm did not increase the chance of producing a child with Down Syndrome, they found. But some older fathers did have an increased risk of having children with dwarfism and "a small fraction of men are at increased risks for transmitting multiple genetic and chromosomal defects."

The study was primarily funded by several grants from the National Institute of Environmental Health Sciences, part of the National Institutes of Health, and the U.S. Environmental Protection Agency.

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On the Net:

Proceedings of the National Academy of Sciences: http://www.pnas.org

Well, this is certainly something to think about for the future.

[Darth Wong]

Since when is this news? I thought this was common knowledge.

[Ariphaos]

There's even a table somewhere about which generation of gametes a male has, how long they last, and where serious problems begin to occur (mid thirties, I think?)

Saw it years ago though, no idea where it is.

[felineki]

I would think this is common sense as well... I mean practically EVERY function of the body deteriorates to some extent as it ages, you can't keep it running perfectly forever.

[Ariphaos]

I would think this is common sense as well... I mean practically EVERY function of the body deteriorates to some extent as it ages, you can't keep it running perfectly forever.

Working on that one :lol:

[Vendetta]

The only reason they can make people think this is news is the contrast between the gradual decline in men (not news at all, it's been known about longer than I've been alive) and the sharp end to reproduction in women.

(The reason for this is likely to be that after a certain point in life, a woman's chances of raising a child successfully drop beyond a threshold at which it becomes more advantageous to her genes to invest the same energy she would use in bearing and rearing them in her grandchildren, who, after all, still carry a quarter of her genes. Male investment is lower simply by virtue of not having to bear the child, hence the lack of cutoff)

[GrandMasterTerwynn]

The interesting thing about this is that while the number of sperm which contain fragmented and damaged genes may go up with age, these defective sperm are every bit as active and competitive as undamaged sperm. Which is why it becomes harder for men to father children at a later age. Fortunately, though, fragmentation of the payload seems to be the worst damage a sperm can suffer, unlike eggs of older women, which tend to carry either too much payload, or too little of it (i.e. too many or too few chromosomes, leading to disorders such as Down's Syndrome.)

[Broomstick]

Fortunately, though, fragmentation of the payload seems to be the worst damage a sperm can suffer, unlike eggs of older women, which tend to carry either too much payload, or too little of it (i.e. too many or too few chromosomes, leading to disorders such as Down's Syndrome.)

Not sure where you're going with this, but approximately half of all individuals with Turner's Syndrome are from sperm lacking a sex chromosome, and whether a particular defect becomes Prader-Willi or Angelman's Syndrome depends entirely on whether the defect was inherited from the mother or the father.