Three is the new two. And in some towns -- especially affluent ones -- four or more is the new three.

Full House

National birth statistics show a small but steady uptick in the number of American women having three children in recent years, leading parents and pediatricians alike to talk about how "three is the new two." In 2004, 28 percent of all American births were to mothers who already had at least two children, up from 26 percent in 1995, according to the National Center for Health Statistics. Specifically for women having their third child, the rate was nearly 10 percent higher in 2004 than it was in 1995. More surprising, in many affluent towns teeming with families managed by highly educated stay-at-home moms, three is far from the end point. Around Wellesley these days, four feels like the new three.