Issues and trends related to adolescent pregnancy and childbearing in the United States are discussed in the 12 papers collected in this publication. Chapters I and II delineate trends in teenage childbearing and explore aspects of psychosocial development and social problems associated with teenage illegitimacy. Chapters III and IV describe first, the sexual and contraceptive experience of young unmarried women in the United States circa 1971 and 1976, and second, aspects of the teenage family planning clinic experience of adolescents. Chapter V presents a reconceptualization of adolescent sexuality that is broadened to include a sense of gender identity and related concepts, sex role behavior, and attitudes about the self and others. Adolescents' access to and use of fertility control services are discussed in Chapter VI. Chapters VII, VIII, IX, X, and XI focus on the health and demographic, psychological, economic, and social consequences of adolescent pregnancy, childbearing, abortion, and parenthood. In conclusion, Chapter XII delineates a theory of teenage pregnancy in the United States. (Author/RH)