A new analysis of the U.S. National Survey of Family Growth (NSFG), comparing 2002 data to 2006-2008 data, found notable changes in teen girls’ sexual behavior. Seventeen-year-old girls in the later cohort were significantly less likely to have been heterosexually active (63% v. 46%) and more than twice as likely to have had same-sex contact (5% v. 11%). This group of teens was also more than three times as likely to have used emergency contraception (5% v. 17%) and less likely to have been pregnant (18% v. 12%). Additionally, the percentage of 17-year-old American girls who had ever been pregnant dropped significantly. Factors that may account for this drop include findings that more were waiting until later in adolescence to become heterosexually involved, more were using emergency contraception if they were heterosexually active, and more were engaging in same-sex behavior. Future research will help determine if this data constitutes a long-term trend. Findings were published in the Archives of Sexual Behavior, in a letter to the editor titled “New Trends in Same-Sex Contact for American Adolescents?” The study was conducted by Nanette Gartrell, MD, Henny Bos, PhD (University of Amsterdam), and Naomi Goldberg, MPP (a Fellow at the Williams Institute during the time that this work was done). Principal investigator Nanette Gartrell, MD, is a 2011-12 Williams Institute Visiting Distinguished Scholar and also affiliated with the University of Amsterdam.