IL6 and chorioamnionitis: Among the 232 women, 28 patients had positive AF cultures, 82 had an elevated AF IL-6 levels (≥ 1.0 ng/mL), 34 had elevated AF WBC counts (≥ 50 cells/mm3), and 56 had histologic chorioamnionitis, and several patients simultaneously met the criteria used in this study for defining IUI (see Supplementary information Table S1 and Fig. 1).