CDC: Effective Birth Control Reduced Teen Birth Rate | More teenage girls are using the best types of birth control, according to a new study from the Centers for Disease Control and Prevent. About 60 percent of teen girls who are sexually active use the most effective methods, like birth control pills or the patch, up for less than half in the mid-1990s. Using only condoms was only moderately effective. Researchers say the increase is due to doctors being more comfortable prescribing hormonal birth control to teens. Between 1990 and 2010, the teen birth rate fell 44 percent, and 43 percent of girls in 2010 said they had sex, down from 51 percent in 1995. CDC researchers surveyed 2,300 girls between 2006 and 2010.