IT HAPPENS all the time - the perfectly put-together and otherwise suitable, 40-something divorced woman gets overlooked as the men in her age group elbow past her to pursue the younger gal at the end of the singles bar.

This is a common scenario repeated night after night at clubs around the country. A local matchmaker once told me she doesn't accept potential female clients of a certain age, regardless of their ability to pay her hefty fees, because of how hard it is to find men willing to date them.

The usual excuse some geezers, uh, I mean older men, give for ignoring mature women and going after females young enough to be their daughters, is that they want to start families and that a woman's risk of having a child with a birth defect increases substantially with age.

But some baby-mamas-in-waiting would be wise to pause and consider the age of the guys they're with as well. There continues to be mounting evidence that it's not just the woman's age that counts. An - ahem - maturing female may well be running out of healthy eggs, but her partner's sperm quality may be on the wane as well.

The latest study to bear this out was published in the European Journal of Epidemiology, which reported that offspring born to male study participants age 45 and older were almost twice as likely to die before reaching adulthood than those born to younger men. Children born to men between 25 and 30 not only lived longer, but were less likely to be diagnosed with congenital defects or diseases such as autism, schizophrenia and epilepsy.

Researchers who studied 100,000 children born from 1980 through 1996 also discovered higher rates of accidental deaths, possibly caused from existing medical conditions. The British newspaper The Telegraph quoted one of the study's researchers: "The risks of older fatherhood can be very profound, and it is not something that people are always aware of."

But word is spreading. Just last year, the American Society of Reproductive Medicine's Fertility & Sterility reported that it takes a man 45 and older five times longer to impregnate his partner than it would if he were in his 20s.

Traditionally, guys have always had the luxury of exploring their romantic options even as women their age scrambled to find The One before their sell-by date. Males had only to look at celebrity role models such as actor Tony Randall, who at 75 married a woman 50 years his junior and then went on to bear two healthy children, as well as other older dads such as Paul McCartney , Michael Douglas and Larry King. Meanwhile, women in their 40s who wanted to give birth could hear the ticking of their biological clocks. Now, it's turning out that men have biological clocks, too.

Maybe one day we'll begin seeing more older women turn into cougars like Kim Cattrall's lusty character in "Sex and the City." Instead of dating older men, maybe women will begin pursuing 30something or younger mates to increase their odds of having a healthy baby. And women who want to have family may come to view even attractive guys in their 40s as too old to bother with. In this new world order, couples such as Demi Moore and her younger hubby, Ashton Kutcher, will be the desired ideal and the boytoy will become the ultimate status symbol. *

Have you peeped a hot trend that hasn't been reported? E-mail and let me know what you know.