Families are the primary socializing agent of young people. Whether young people develop successfully depends substantially on whether families provide the physical and psychological conditions children need to acquire developmental competencies. This section begins with a review of the available evidence regarding family-focused prevention at each developmental phase. It then moves to discussion of interventions that can affect family functioning and mental, emotional, and behavioral outcomes regardless of developmental phase. The section closes with a discussion of the effects of family economic well-being on diverse internalizing and externalizing disorders.

Pregnancies among teenagers, particularly those younger than 16 years of age, are a risk factor for preterm birth, intrauterine growth retardation, and perinatal complications. Adolescent pregnancies are associated with single motherhood, low educational attainment, and low wages, all of which jeopardize children’s development (Ayoola, Brewer, and Nettleman, 2006). Empirical evidence that unintended pregnancies can be prevented by specific pregnancy prevention programs is limited. Higher-quality studies on average show discouraging outcomes for pregnancy, and most studies are pre-post or quasi-experimental. One meta-analysis of prevention strategies aimed at delaying sexual intercourse, improving use of birth control, and reducing the incidence of unintended pregnancy among adolescents found no evidence of beneficial effects for any targeted outcomes (DiCenso, Guyett, et al., 2002). Another found evidence of an effect on contraception and pregnancy but not on sexual activity (Franklin, Grant, et al., 1997).

Although effective methods of intervening to prevent teenage pregnancies through family-, school-, or clinic-based programs are elusive, further research on the larger normative and cultural context for teenage sexuality may lead to approaches that are more effective. The recent decline in teenage pregnancies in the United States (Ventura, Mosher, et al., 2001), for example, suggests that opportunities to address malleable influences do exist.

Significant risks during fetal development for adverse neurobehavioral outcomes include genetic anomalies, poor maternal nutrition, maternal