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Guys: We understand that when you're in the early stages of a relationship, it's tempting to bring up the baby issue, especially if the big 30 isn't too far off. Some of your friends may even suggest making it clear on the first date that you need to start trying to have kids soon, because why waste time with someone who isn't serious about settling down? Just bear in mind that you might very well scare the girl off, since she can always put her eggs on ice and then marry some virile 25-year-old once she's established her career.

Okay, that was just our little fantasy of what the future may hold for relationships given the mounting evidence that sperm, once its manufacturer is out of his twenties, is of decreasing quality and likely to be "damaged."

The damage can be caused by glitches in the process of replicating DNA millions of times over, reduced efficiency of the DNA repair mechanism, or attributed to environmental factors like stress, smoking or heavy drinking.

The outcome? Children born to older fathers are at risk of autism, schizophrenia, and lower IQs. So women may want to date older men for the expensive dinners and stimulating conversation, but when it comes to baby-making, they ought to go for a dewy-skinned youth. Which, Hollywood scriptwriters, is also your pitch for a cougar-cub comedy starring Zack Ephron and Anna Faris.

For Whom The Clock Ticks [Newsweek]