Teenage birth rate is not nearly the issue it was 20 years ago.

According to the US Centers for Disease Control and Prevention, teenage birth rates plummeted 57 percent over the last two decades.

The CDC estimated there were 4 million fewer births by teenagers over this time period. They found reductions in teenage births in almost all 50 states and all race and ethnic groups. However, the US still has one of the highest teenage birth rates among developed countries.

Bill Albert, chief program officer of The National Campaign to Prevent Teen and Unplanned Pregnancy, said that the numbers jumped out to him. He said because only 40 percent of teen mothers graduate from high school, 40 percent of 4 million is a large number.

Additionally, researchers estimate that the reduction in births by teenagers also saved taxpayers $12 million in 2010 alone. This figure comes from the increased likelihood that teen mothers will need food stamps and other government assistance. The study researchers estimate that each child born to a teen mother costs tax payers $1,700 a year from birth until he or she turns 15.

Stephanie Ventura, a senior demographer for the CDC's National Center for Health Statistics said the current teen birth rate, 26.6 of every 1,000 teen girls, is one-third of the historically highest rate of teenage births.

"In the old era, most teens who had a baby were married and you could support a family on the education you had from high school, so it was not as much of a concern," she said."

By the late 1980s, however, teenage pregnancy was seen as detrimental to career development and the mother's ability to contribute to a two-income family.

"These historic declines in teen pregnancy and births truly represent one of the nation's greatest success stories over the past two decades," Albert said.

This decline in teen birth rates could be attributed to less sex among teenagers and more contraception. Teenagers now also have more access to effective methods of contraception.

Albert said living in the era of HIV was also likely an issue since they knew sex had potential consequences for boys and girls.

He said TV shows such as "Teen Mom" and "16 and Pregnant" were also likely factors since they portray teenage motherhood as sobering and tough.

Ventura said one thing that was not a big factor was abortion, since abortion rates are declining faster than the birth rate.