Births fell from an all-time high in 2007 of 4,316,233 to 4,131,019 in 2009, a decline of 4 percent. . . . In 2007, there were 69.5 births per 1,000 women ages 15 to 44 compared with 66.7 in 2009. This is referred to by NCHS as the fertility rate, but is also often called the general fertility rate (GFR).
By age, the largest decline was among women ages 20 to 24. Childbearing fell from 106.3 births pr 1,000 women in that group in 2007 to 96.3 in 2009, a 9 percent decline. . . . Fertility among the 25-to-29 age group, the next older, fell by 6 percent. That group, which has had the highest rate in recent years, dropped from 117.5 in 2007 to 110.5 in 2009. The decline was far less, only 2 percent among women in their 30s and even rose among women in their 40s, although latter group has much lower rates. . . .
[F]ertility rates have fallen . . . : 3% for non-Hispanic whites between 2007 and 2009, 4% for non-Hispanic blacks, 9% for Hispanics, 3% for American Indians and Alaskan natives, and 4% for Asian and Pacific islanders.
The likely cause for the slump is the financial crisis and recession that followed. Birth rates are mildly cyclic. The U.S. has one of the highest fertility rates in the developed world, which was hovering at just over the replacement rate in 2007. The slump probably brings the U.S. to a bit below the replacement rate (which is about 2100 children per 1000 women per lifetime).
The shift accentuates the recent trend of fertility rates declining more for lower income, minority, and younger women, while declining less or increasingly among more affluent and older women, in substantial part due to fertility treatments (a trend that has also greatly increased the number of multiple births and parental age related congenital conditions). The last decade or so is the first time in almost a century in which affluent people have more children than less affluent people.
It is also a fit to the fact that the recession has dampened new household formation, and has pushed people into high school and college and out of the labor force.
While teen births are at near record lows, about 40% of all births are to unmarried mothers, including majorities of births to African-American and Native American women.
As an aside, fertility rates in some of the Baltic states are finally starting to recover after a profound post-communist era slump.