Expression of IL1B is elevated in women with chorioamnionitis at the time of delivery. A, Expression of IL1B in maternal blood measured in a control group (n = 12), women without chorioamnionitis at consent (n = 2) and delivery (n = 4), and in women with chorioamnionitis at consent (n = 5) and delivery (n = 11). Mean and SEM are graphed, *P < .05. B, Expression measured over time from consent until delivery of IL1B in a patient with chorioamnionitis. This patient developed Escherichia coli septicemia as did her baby. IL1B indicates interleukin 1β; SEM, standard error of the mean.