There are significant differences in three subtypes of memory/effector T cells (HOPX+ CD4+ T cells, ZNF683+CD8+ T cells, and KLRB1+CD8+ T cells) between mid- and late pregnancy. In late pregnancy, intercellular interaction was enhanced and effector CD8+ T cells highly expressed infection-related pathways. A rare T cell subtype, “XIST+ T cells,” may be involved in the regulation of immune-related gene transcription and translation with a strong female bias.