Over the past decade, several large-scale school-based studies of adolescents in Canada and the U.S. have documented health disparities for lesbian, gay and bisexual teens compared to their heterosexual peers, such as higher rates of suicide attempts, homelessness, and substance use. Many of these disparities have been linked to “enacted stigma,” or the higher rates of harassment, discrimination, and sexual or physical violence that sexual minority youth experience at home, at school, and in the community. An unexpected health disparity for lesbian, gay and bisexual youth is their significantly higher risk of teen pregnancy involvement (between two and seven times the rate of their heterosexual peers), especially in light of declining trends in teen pregnancy across North America since the early 1990s. What is behind this higher risk? Is it getting better or worse? Using the province-wide cluster-stratified British Columbia Adolescent Health Surveys from 1992, 1998, and 2003, this paper explores the trends in pregnancy involvement, related sexual behaviours, and exposure to forms of enacted stigma that may help explain this particular health disparity for gay, lesbian and bisexual youth in Canada.