For the past several decades, the teenage birth rate in the United States has exceeded that of other industrialized nations. To explore the factors behind this high birth rate, this volume summarizes recent research conducted in the United States on the perceived causes of teenage childbearing. This review is organized around the events leading to teenage childbirth, including the transition into having sexual intercourse; use of contraception at first intercourse and use at current or recent intercourse; and, if pregnancy occurs, decisions about abortion, adoption, and marriage. Although most teens do not want to become parents, those most at risk of becoming parents during their teen years are those least well-situated to raise a healthy, well-adjusted, and high-achieving child. Factors that affect sexual and pregnancy risk-taking among disadvantaged youth are not well understood and require better data and new research; researchers would need to focus on the correlates of pregnancy prevention among low-income adolescents. The effects of varied forms of mass media, including television, music, and videos, also require better data and carefully designed empirical research. Likewise, research on the effects of policy variables, such as welfare and family planning services, remains inadequate. Results are presented in 31 tables, charts, and graphs. Contains a bibliography of over 400 items. (RJM)