Pregnancy risk among the younger sisters of pregnant and childbearing adolescents.

There is increasing evidence that younger sisters of childbearing teenagers are at increased risk for adolescent childbearing. We critically review this research and discuss three plausible theoretical explanations (social modeling, shared parenting influences, and shared societal risk) why the younger sisters of childbearing adolescents would themselves be at risk for teenage pregnancy. Considerations for preventive interventions aimed at the younger sisters of pregnant teenagers and directions for future research are discussed.