The ticking male timebomb

It's known that women who postpone childbirth into their 30s and 40s place their offspring at risk for countless disorders and diseases. Why that is so might surprise you.

Writing in The Wall Street Journal, Jennifer Vanderbes suggests that it's because women in their 30s tend to couple off with older men. And when it comes to fathering healthy children, older men, it turns out, are just as much at the mercy of their biological clocks as women.

Several years ago researchers at the Mount Sinai School of Medicine reported that a man over 40 is almost six times as likely as a man under 30 to father an autistic child. Since then, research has shown that a man's chances of fathering offspring with schizophrenia double when he hits 40 and triple at age 50. The incidence of bipolarity, epilepsy, prostate cancer and breast cancer also increases in children born to men approaching 40.

After each ejaculation, a man regenerates millions of new sperm cells, and with each cellular replication, the chances rise of an error in genetic coding. 

These "new" sperm might still be able to fertilize an egg, but they can contain dangerous mutations. "As men get older, maybe there is some sperm available, but a lot of that DNA may be abnormal," says Harry Fisch, author of the pioneering 2004 book The Male Biological Clock.

Here's a chart showing the rising age at which men get married.

That's the average, meaning half get married at a later age. And here's a chart showing the rising diagnoses of autism.

This may be one piece of the puzzle of the apparent epidemic of autism.