IL6 and chorioamnionitis: To simulate the fetal exposure to maternal inflammation (FEMI) induced by chorioamnionitis, pregnant mice (C57BL/6J, IL-6−/−, RAG−/− or TNFR1−/−) were injected intraperitoneally on embryonic day (E)15.5 with lipopolysaccharide (LPS; 100 μg/kg body weight).