Annual summary of vital statistics: 2006.

US births increased 3% between 2005 and 2006 to 4,265,996, the largest number since 1961. The crude birth rate rose 1%, to 14.2 per 1000 population, and the general fertility rate increased 3%, to 68.5 per 1000 women 15 to 44 years. Births and birth rates increased among all race and Hispanic-origin groups. Teen childbearing rose 3% in 2006, to 41.9 per 1000 females aged 15 to 19 years, the first increase after 14 years of steady decline. Birth rates rose 2% to 4% for women aged 20 to 44; rates for the youngest (10-14 years) and oldest (45-49) women were unchanged. Childbearing by unmarried women increased steeply in 2006 and set new historic highs. The cesarean-delivery rate rose by 3% in 2006 to 31.1% of all births; this figure has been up 50% over the last decade. Preterm and low birth weight rates also increased for 2006 to 12.8% and 8.3%, respectively. The 2005 infant mortality rate was 6.89 infant deaths per 1000 live births, not statistically higher than the 2004 level. Non-Hispanic black newborns continued to be more than twice as likely as non-Hispanic white and Hispanic infants to die in the first year of life in 2004. For all gender and race groups combined, expectation of life at birth reached a record high of 77.9 years in 2005. Age-adjusted death rates in the United States continue to decline. The crude death rate for children aged 1 to 19 years decreased significantly between 2000 and 2005. Of the 10 leading causes of death for children in 2005, only the death rate for cerebrovascular disease was up slightly from 2000, whereas accident and chronic lower respiratory disease death rates decreased. A large proportion of childhood deaths, however, continue to occur as a result of preventable injuries.