NCHS has released a report that presents 2011 data on U.S. births according to a wide variety of characteristics. The vast majority of these findings were previously published in October 2012 in “Births: Preliminary Data for 2011.”
Findings that were not in the preliminary report:
The 2011 twin birth rate was 33 per 1,000 total births, essentially unchanged from 2009 and 2010. The rate of twin births rose 76 percent from 1980 to 2009-2011. The triplet and higher order multiple birth rate was also essentially unchanged from 2010, but has declined 29 percent since 1998.
The mean age of mother at first birth rose slightly to 25.6 years in 2011, up from
21 years in 1970. The increase in the mean age in 2011 reflects, in part, the relatively large decline in births to women in their teens and twenties.
Mean age at first birth varied by race and Hispanic origin in 2011, from 22 years for American Indian or Alaska Native (AIAN) women to 29 years for Asian or Pacific Islander (API) women. For the three largest race and Hispanic origin groups, average ages at first birth were 23 years for non-Hispanic black, 24 years for Hispanic, and 26 years for non-Hispanic white women. Among the specified Hispanic groups, average ages ranged from 23 years for Mexican women to 26 years for Cuban women. Average age at first birth increased for women in the three largest race and Hispanic origin groups in 2011, but decreased for AIAN and API women.