Teenage birth rates in America have fallen to historic lows, according to 2010 data released Tuesday in a report by the National Center for Health Statistics.

The year 2010 saw the fewest babies born to teenagers since 1946.

The birth rate for teenage girls between 15 and 19 years old fell 9 percent from 2009 to 2010, reaching a low of 34.3 births per 1,000 women.

The reported data confirms the declining long-term trend in teenage childbearing over the last 20 years. The report cites an increase in contraception use, such as condoms and hormonal birth control, in addition to less sex among teenagers, as a potential reason for the decline in teenage birth rates.

It's a combination of less sex and more contraception. Both sides should declare victory, Bill Albert, chief program officer for the National Campaign to Prevent Teen and Unplanned Pregnancy, told CNN, referring to groups supporting contraception and those supporting abstinence. I would resist the temptation for a magic bullet to explain the declines in teen pregnancies. I suspect it's a rich brew of reasons why the rates are going down.

Although the NCHS does not assign a specific cause for the significantly low birth rates, it appears to be that teenagers are delaying sex and increasingly using effective contraception.

With teens, there are a lot of factors. The economy is cited for an overall downturn in the number of births. With teens, there are public policy programs directly addressing this teen pregnancy issue. It's a mixture of things involved. We cannot tease that out with the data set that we have, Brady Hamilton, co-author of the NCHS report, told CNN.

In 1991, teen birth rates peaked with a rate of 61.8 percent for every 1,000 women.

If the 1991 rate had continued, teenage girls from 1992 through 2010 would have added 3.4 million births to the American population.

Although progress is being made, the United States still has the highest teenage birth rate among industrialized countries.

In comparison, Lithuania ranks at 17 teenage births per 1,000 women aged between 15 and 19 years old, less than half of the American rate. Poland is recorded at 16 per 1,000 while Canada is at 14 per 1,000, according to the UN Demographic Yearbook.

The figure below, taken from the study published online, highlights the teen birth rates in each state.