Immune activation represents an adaptive reaction triggered by both noxious exogenous (microbes) and endogenous [high mobility group box-1 protein (HMGB1), S100 calcium binding proteins] inducers of inflammation. Cell stress or necrosis lead the release of HMGB1 and S100 proteins in the extracellular compartment where they act as damage-associated molecular pattern molecules (or alarmins) by engaging the receptor for advanced glycation end-products (RAGE). Although the biology of RAGE is dictated by the accumulation of damage-associated molecular pattern molecules at sites of tissue injury, the role of RAGE in mediating antenatal fetal injury remains unknown. First, we studied the relationships at birth between the intensity of human fetal inflammation and sRAGE (an endogenous RAGE antagonist), HMGB1, and S100 protein. We found significantly lower sRAGE in human fetuses that mounted robust inflammatory responses. HMGB1 levels correlated significantly with levels of interleukin-6 and S100 in fetal circulation. We then evaluated the levels and areas of tissue expression of RAGE, HMGB1, and S100 in specific organs of mouse fetuses on E16. Using an animal model of endotoxin-induced fetal damage and preterm birth, we determined that inflammation induces a significant change in expression of RAGE and HMGB1, but not S100, at sites of tissue damage. Our findings indicate that RAGE and Conventional wisdom holds that the primary causes of the high neonatal morbidity and mortality attendant preterm birth are complications of immature organ systems.1-4 However, a growing body of investigation suggests that the poor outcome observed in many preterm children is not entirely dependent on their gestational age at birth. 2,5,6 After correcting for gestational age, several risk factors remain significantly associated with an increased risk of cerebral palsy, such as intra-amniotic infection, histological chorioamnionitis, prolonged rupture of the membranes, and hypoxemic fetal growth re-