T helper subpopulations present in the decidua and in the peripheral blood of those experiencing unexplained recurrent abortion and those experiencing successful pregnancy. To investigate the CD4+ cell subsets that produce IL-22, the percentages of Th1-, Th2-, Th0-, Th17-, Th17/Th1-, Th17/Th2-, and Th17/Th0 cells, which do not produce IL-22 and which also produce IL-22 (Th1/IL-22+, Th2/IL-22+, Th0/IL-22+, Th17/IL-22+, Th17/Th1/IL-22+, Th17/Th2/IL-22+, and Th17/Th0/IL-22+) were analyzed. Cytokines were measured in the supernatants of the CD4+ T cell clones derived from the decidua and peripheral blood of those experiencing successful pregnancy and those experiencing unexplained recurrent abortion (URA) (Experiment 1 in Section 4.3) by a multiplex bead-based assay. The statistical analysis was performed with the chi-square test.