Three months ago, I took an abrupt vacation from these pages when my baby son arrived early. Alas, I never got to write the "what I've learned about marketing to pregnant women" column that was meant to be my swan song into maternity leave.

Now I am part of the demographic I dreaded most, "Moms like Me," instantly identified by the mere extension of my gene pool. Overnight, in the view of some marketers at any rate, I ...