IL-1β is elevated in amniotic fluid (5, 46, 64–70), placenta (6), and maternal serum (71–73) from chorioamnionitis-affected pregnancies.IL1B mRNA expression is increased in maternal serum (74) during chorioamnionitis.Conflicting evidence: reports of increased IL-1 in cord blood from chorioamnionitis-affected pregnancies (75–77) however not in all studies (78–81). May require concurrent funisitis (77).IL-1Ra is increased in amniotic fluid, cervical secretions and cord blood (82–85) from chorioamnionitis-affected pregnancies.Polymorphisms of IL1RN are associated with acute deciduitis (86). This evidence concerns the gene IL1A and chorioamnionitis.