As a result, in 2011, the American birthrate hit a record low, with 63 births per 1,000 women ages 15 to 44, led by the decline in births to immigrant women. The national birthrate is now about half what it was during the baby boom years, when it peaked in 1957 at 122.7 births per 1,000 women of childbearing age.
The decline in birthrates was steepest among Mexican-American women and women who immigrated from Mexico, at 25.7 percent. This has reversed a trend in which immigrant mothers accounted for a rising share of births in the United States, according to a recent report by the Pew Research Center. In 2010, birthrates among all Hispanics reached their lowest level in 20 years, the center found.