Downs Syndrome and maternal age

Just last week, I was chiding a young friend that he ought to marry his girlfriend (with whom I'd set him up last year) so they could start having babies. Playing matchmaker with young folks is an amusing hobby, partly because urging 20-somethings to wed and procreate is so politically incorrect in an era when societal pressure is almost entirely in the other direction.

Young people nowadays are told they should concentrate on establishing their careers rather than starting families while they're young. But the careerist/materialist path, however sensible, strikes me as far less romantic than the impulsive let's-go-see-the-preacher approach. And as a Southerner, I can't resist the old-fashioned appeal of "Paint the shotgun white, Pa -- it's going to be a formal wedding!"

However, while I was researching my last post (about those idiotic left-wing Trig Palin rumors), I noticed that a commenter at Michelle Malkin's blog had linked something that puts the weight of science behind my old-fashioned romantic ideas of young love. It's a chart correlating the frequency of Downs Syndrome with maternal age, and it is a powerful argument against postponing motherhood.

For women ages 20-24, the frequency of Downs Syndrome is 1 in every 1,400 live births. By age 35, however, the frequency is 1 in every 350 births -- a quadrupling of risk. At age 39, the frequency is 1/140 -- 10 times the risk at age 20-24.

Risk is not certainty, of course. My wife and I have six children, the three youngest of whom are all healthy, even though they were born when my wife was 35, 37 and 39. Downs Syndrome, however, is only one of the serious complications associated with advanced maternal age. Indeed, waiting to have a baby increases the likelihood that you'll never have babies at all.

The American Society for Reproductive Medicine reports that infertility affects 7% of women ages 20-24, but 15% of women ages 30-34 and 22% of women ages 35-39. In other words, a delaying motherhood by 10 years doubles a woman's risk of infertility, while a delay of 15 years triples the risk.

Clearly, nature favors the young when it comes to motherhood. Thus, I claim scientific support for my advocacy of that wild-and-crazy romantic notion that young folks ought to get married and make babies. So ladies, next time that fellow starts lovin' up on you, just whisper in his ear, "Let's do something scientific!"