The birth rate among teens in the United States–34.3 per 1,000 girls–is at a record low, according to a new Centers for Disease Control report. And all racial and ethnic groups saw dramatic decreases:

Teenage birth rates for ages 15-19, 15-17, and 18-19 declined significantly for all race and Hispanic origin groups. Declines for ages 15-19 ranged from 9 percent each for non-Hispanic white (to 23.5 per 1,000 in 2010) and non-Hispanic black teenagers (51.5); to 12 percent for [American Indian and Alaska Native] (38.7) and Hispanic teenagers (55.7); and 13 percent for [Asian and Pacific Islander] teenagers (10.9).

The report, which compares 2009 and 2010 birth records from all 50 states, shows that across race, the 15-to-19-year-old birth rate dropped 9 percent. It’s the largest single-year decline since 1946-1947–a period marked by widespread bread and beef shortages, skyrocketing inflation and postwar uncertainty.

The data also show the lowest birth levels ever reported for women in their early 20s: Those ages 20 to 24 had 90 births per 1,000 women, down 6 percent from 2009. Women in their mid-to-late 20s, their 30s and, interestingly, those who were unmarried also had fewer babies in 2010.

In fact, the only group to have a higher birth rate last year were women in their 40s. At 10.2 births per 1,000 women, those in the 40-plus set enjoyed the highest rate since 1967.

The CDC report, which comprises preliminary numbers from 2010, doesn’t cite a cause for declining birth rates among teen girls and young women. But some experts point to the ever-tanking U.S. economy. "I don’t think there’s any doubt now that it was the recession," Carl Haub, a demographer with the Washington, D.C.-based Population Reference Bureau, was quoted as saying by CBS News. "It could not be anything else."

In an upbeat statement released yesterday, Sarah Brown, CEO of The National Campaign to Prevent Teen and Unplanned Pregnancy, attributed the decline in teen births to "the magic formula of less sex and more contraception":

"I am aware of no other social problem that has improved so dramatically over so many years. Progress in reducing teen pregnancy has been nothing short of remarkable — the teen birth rate has declined a stunning 44 percent between 1991 and 2010. There have been impressive declines in all 50 states and among all racial/ethnic groups. Not so long ago, teen pregnancy was viewed as intractable and inevitable. This report shows that too early pregnancy and child-bearing are 100 percent preventable. The magic formula of less sex and more contraception is responsible for this great good news."

In addition to the recession, "evidence-based" sexuality education programs, and "teens themselves," Brown tipped her hat to glamour-deficient reality shows such as MTV’s "16 and Pregnant" and the channel’s "Teen Mom."

"Teens are being more careful for a number of reasons, including the recession, more media attention to this issue–including the ’16 and Pregnant/Teen Mom effect’–and more attention to and investment in evidence-based programs. But at the end of the day, the thanks and admiration go to teens themselves."

Get the full CDC report, National Vital Statistics Report, Volume 60, Number 2 here.

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