CONTEXT: The siblings of teenage parents are known to be at very high risk of teenage pregnancy, but little is known about how an older sister's childbearing affects a younger sibling's risk. Understanding these influences could help address the very high rates of pregnancy and childbearing among Latino adolescents.

METHODS: From 2005 through 2007, a sample of 41 Mexican American 12–18-year-olds from southern California completed in-depth interviews about how an older sister’s teenage childbearing had affected them. Themes that emerged were categorized as risk factors (circumstances that increased youths’ likelihood of becoming involved in a teenage pregnancy) or protective factors (conditions that reduced this likelihood) on the basis of well-established findings in the literature.

RESULTS: Interview data reflected six risk factors and 11 protective factors. The most commonly reported risk factors (discussed by more than a quarter of participants) were that youths did not perceive early parenting as a hardship, had increased difficulties in school and wanted to have a baby too. The most commonly cited protective factors (mentioned by more than half) were an increased motivation to avoid early parenting, an increased appreciation of the difficulties of parenting, mothers' explicitly discouraging early parenting and youths' feeling of greater closeness with their mother.

CONCLUSIONS: Interventions that build on the protective factors that result when a youth's older sibling has a teenage birth, while reducing the risk factors, might help families prevent younger children from becoming involved in a teenage pregnancy.