(WASHINGTON) -- Many adolescent girls are confused about how easy it is to become pregnant, especially when contraceptives aren't used, according to a new report by the Centers for Disease Control and Prevention (CDC).
Data taken from the 2004 to 2008 Pregnancy Risk Assessment Monitoring System of females between 15 and 19 years old found that one in two teens who had an unwanted pregnancy reported that neither they nor their partner used birth control.
In the group that dispensed with contraceptives, a third of girls claimed that they didn't think they could pregnant at that time, 23 percent said their partner refused to use birth control and about the same number had no problem with getting pregnant.
Contraceptive use also didn't prevent teens from becoming pregnant, with 45 percent using either high effective or moderately effective birth control methods while five percent depended solely on the rhythm method.
The CDC says more needs to be done to educate teens about pregnancy and how to prevent it.
Copyright 2012 ABC News Radio