Whenever I take the kids to the park, I feel a little younger because I see plenty of parents in their late 30s and early 40s pushing their kids in baby joggers or Maclaren strollers. But, I also know few parents can afford houses in my hood until they are well along their salary evolution, and I wonder if it's an urban illusion.

Then I saw a report today at the National Center for Health Statistics blog and I realized new parents are graying. In 2004, 579,000 U.S. women between the ages of 35 and 44 gave birth, according to the Centers for Disease Control agency. Ten years earlier 435,000 mothers in the same age group gave birth.

If you go back even further, you discover far fewer, only 178,000 moms, in that age bracket giving birth, though I'm still checking to ensure those two data sets are exactly the same.

We all know the obvious reasons for older moms and dads. We are marrying later, have better fertility treatments etc... But, you have to wonder how far this trend will go. In 1994, there were only 2,507 moms age 45 to 49 who gave birth in 1994 - the report didn't even offer a number for women 50 and older.

Ten years later the number more than doubled to 5,748.

(The NCHS blog is a nerdy but cool site, with lots of interesting family stats, such as the age of mothers when they have their first child.)