Intrauterine infection is associated with chorioamnionitis, preterm birth, and the fetal inflammatory response syndrome (FIRS). Choriodecidual infection represents an intermediate stage of ascending reproductive infection, providing a model of infection-driven fetal inflammation, without direct microbial exposure of the fetus. The current study aims to examine the inflammatory responses in the placenta and fetal brain in response to choriodecidual Ureaplasma infection.