Researchers from the University of Washington found that adolescents who receive comprehensive sex education are significantly less likely to become pregnant than adolescents who receive abstinence-only-until-marriage or no formal sex education. The study, based on a national survey of 1,719 teens ages 15 to 19, is the first population-level evaluation of the effectiveness of both abstinence-only and comprehensive sex education programs. The results are very promising for comprehensive sex education.According to Pamela Kohler, the study's lead author, "It is not harmful to teach teens about birth control in addition to abstinence."This study joins a host of others that prove that abstinence-only does little and comprehensive sex education does much for our teens. The dangers of abstinence-only are nothing new – one well-known study by Mathematica found that students who participated in abstinence-only programs are just as likely to have sex as their peers who did not participate.Yet in the face of this overwhelming evidence, 1 in 4 teens receive only abstinence-only instruction. On top of that, 9 percent of teens receive no sex education at all, particularly those in rural or poor areas. Thankfully, that leaves two-thirds of students in comprehensive sex ed. As temporarily reassuring as that might be, we cannot also lose sight of the fact that 1 in 4 teen girls have an STD.This sobering fact also points to how much work we have left to do. The University of Washington study does not speak to how comprehensive sex ed should be implemented. Clearly this is a question to be handled carefully by both parents and administrators alike, as we continue to improve and expand the reach of comprehensive sex education programs.