Chronic psychological stress may raise the risk of preterm delivery by raising levels of placental corticotropin-releasing hormone (CRH). Women who have been the targets of racism or personal violence may be at particularly high risk of preterm delivery. The aims of this study are to examine the extent to which: (1) maternal experiences of racism or violence in childhood, adulthood, or pregnancy are associated with the risk of preterm birth; (2) CRH levels are prospectively associated with risk of preterm birth; and (3) CRH levels are associated with past and current maternal experiences of racism or violence. We have begun to examine these questions among women enrolled in Project Viva, a Boston-based longitudinal study of 6000 pregnant women and their children.