Teen pregnancy down thanks to shows like '16 and Pregnant?'

A new study suggests shows like MTV's "16 and Pregnant," are leading to fewer teen pregnancies.

The study, just released by the National Bureau of Economic Research, says "16 and Pregnant" ultimately led to a 5.7% reduction in teen births in the 18 months after its premiere on TV, which equates to about 20,000.

In 2011, a total of 329,797 babies were born in the United States to girls between the ages of 15 and 19; that's a rate of 31.3 births per every 1,000 girls, according to the Centers for Disease Control and Prevention.

In the past four years, the teen pregnancy rate has dropped even more dramatically at a rate of about 7.5% per year.

When the researchers learned that Sarah Brown, CEO of the National Campaign to Prevent Teen and Unplanned Pregnancy, thought MTV's shows may have something to do with it, they thought: "Could that really be true?"

"16 and Pregnant" premiered in June 2009 and has been on for five seasons, with a total of 47 episodes through October 2013.

The show features one teen every episode and follows her through several months during and after pregnancy.

The documentary-style show inspired several spin offs, including the popular "Teen Mom."

But they are often criticized for glamorizing teen pregnancy.

The study's authors, Kearney and Levine, looked at Nielsen ratings as well as search data from Google Trends and Twitter to determine the show's potential impact on teen birth rates.

They recorded spikes in Google searches and Twitter mentions about the show when new episodes aired and looked specifically for searches on terms such as "birth control" and "abortion."

They then analyzed geographic data to see whether locations with higher search activity and tweets about "16 and Pregnant" showed higher levels of searches and tweets about birth control and abortion. They did.

The researchers also looked to see whether high viewership in certain areas corresponded with a bigger drop in teen births. It did.

They concluded, "The results of our analysis indicate that exposure to '16 and Pregnant' was high and that it had an influence on teens' thinking regarding birth control and abortion."

The researchers did note that they are not saying that MTV is solely responsible for the declining teen birth rate.

But that about half of the recent dramatic decline can be attributed to the recession, Kearney says.

Kearney believes TV shows like "16 and Pregnant" work to deter teens in a similar way.

Making the immediate cost clear seems to get through to teens more than statistics that show what happens to teen parents when they're 25, Kearney says.