Evidence strongly indicates that adolescent pregnancies have a generational and cyclical nature and that adolescent mothers tend to have offspring who later become adolescent parents themselves. Also, young girls experiencing a first pregnancy tend to have a second and even third pregnancy during their adolescent years. These characteristics produce an exponential effect on the probability that an adolescent, who has a family history of early pregnancies, will be involved in one or more pregnancies. Sexual activity leading to repeated adolescent pregnancies through generations is not sex specific. The prevention of unwanted and undesirable adolescent pregnancies and the promotion of healthy sexual development and responsible decisionmaking need to be incorporated in health goals. The significant development stages in which certain target populations require attention are preconception, pregnancy, birth and delivery, infancy and early parenting, school age, and puberty and early adolescence. 2 tables, 2 figures, and 17 references. (Author abstract modified)