A new survey from the Centers for Disease Control and Prevention has found a dramatic increase in the amount of teenage girls in the U.S. using the morning-after pill.

The emergency contraceptive contains high doses of the female hormone progestin and reduces the risk of pregnancy by 90 percent if taken within 72 hours of unprotected intercourse. The pill usually costs $35 to $50.

The CDC report found in spike in the pill's usage from 1 in 12 sexually active teen girls a decade ago to 1 in 5 girls now. The survey is based on interviews with about 2,000 people, ages 15 to 19 from 2011 to 2013.

The increase is a likely reflection of how easy it has become to buy these pills.

The FDA approved Plan B One-Step for sale in the U.S. in April 2013 to anyone 15 years of age and older, without a prescription, as long as they could show proof of age. But two months later, the Obama administration ended federal efforts to block over-the-counter availability. As a result, any girl could now purchase the pill without going through a pharmacist, according to Examiner.

Bill Albert, chief program officer for the National Campaign to Prevent Teen and Unplanned Pregnancy, said that the fact that more teenage girls have bought the pill since it became easier to buy is a sign that "teens, like adults, often are not very good at contraception," according to Fox News.

"In the battle between sex and sex with contraception, sex often wins," he added.

Another heartening fact that was revealed in the survey is that while the numbers of teen girls using the morning-after pill increased, the number of teens who do engage in sexual activity fell from 1988 to 2013. One possible reason for the decline could be greater awareness regarding STDS, including HIV/AIDS and greater efforts to improve sex education, according to Wall Street OTC.

Good news? Bad news? We'll have to educate our children while we wait and watch.