Features of T‐cell subsets during pregnancy. (A) GO term enrichment of genes which highly expressed in different trimester compared to non‐pregnancy in T cell (CD8+ naïve T, CD8+ cytotoxic T, CD4+ naïve T, CD4+ cytotoxic T, NKT, Treg, proliferative T, MAIT and other T). Red means upregulation compared to non‐pregnancy, blue means downregulation compared to non‐pregnancy. (B and C) Boxplots of the cell scores of two GO biological process terms (T‐cell receptor signalling pathway and T‐cell activation) in CD4+ T, CD8+ T, NKT and Treg cells across four conditions. Wilcoxon rank‐sum test was applied. (D and E) Box plots of the cell scores for CD4+ T, CD8+ T, NKT and Treg cells of cytotoxic and exhausted associated genes across four conditions. Wilcoxon rank‐sum test was applied. (F and G) Box plots of the cell scores of two GO biological process terms (response to type I interferon and defense response to virus) in CD4+ T, CD8+ T, NKT and Treg cells across four conditions. Wilcoxon rank‐sum test was applied. (H and I) Box plots of the cell scores of two GO biological process terms (RNA splicing and alternative mRNA splicing via spliceosome) in CD4+ T, CD8+ T, NKT and Treg cells across four conditions. Wilcoxon rank‐sum test was applied. (J) Correlation test between ISGs expression level in CD4+ T, CD8+ T, NKT and Treg cells with gestational weeks. Correlation analysis using the Pearson's product‐moment correlation. (K) Dot plot of ten genes expression pattern across four conditions, including CD27, TRAC, TRBC1, TRBC2, CD3D, CD3E, CD3G, CD2, LCK and PTPRC. (L) The difference in expression levels of above ten genes in CD4+ T, CD8+ T, NKT and Treg cells between three periods of pregnancy and non‐pregnant controls. (M) HNRNPL expression pattern across four conditions, the graph on the right shows the significance of three periods of pregnancy compared to non‐pregnant controls. Wilcoxon rank‐sum test was applied. All differences with p < 0.05 are indicated. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, ns = not significant