Births are due to increase in the U.S. thanks to the general demographics. The baby boomers had children from the late '70s to the early '90s and now the "echo boomers" (our generation) are beginning to have kids, so the number of child bearing young women is on the rise.
In my area, people tend to have kids about a year or two younger than in the rest of the state, so we see these trends earlier. The number of births peaked and plateaued from the baby boom from 1951-1962 or so before falling rapidly (by about 40%) by 1967 before slowly rising throughout the '70s and then rising rapidly in the late '70s, and plateauing again all through the '80s before falling rapidly in the early '90s... and the process started over... births slowly rose from 1995-2000 but have really begun to boom since about 2004.
Births will continue to rise and stay high here for another 10 years or so before falling again.
From 2000 to 2007 our county grew just under 10%, but the number of births jumped 22%. During the '90s, population grew 16% but births fell about 10%.
Indeed, remember that the mean age at first time birth is 25 years, therefore I´m awaiting another US baby-boom by 2020, when the women born around 1990-1995 will get their kids. That's because the absolute number of births in 1990-1995 was considerably higher than from 1975-80 (the women who are now getting their children).
