Single Cell Profiling at the Maternal–Fetal Interface Reveals a Deficiency of PD-L1⁺ Non-Immune Cells in Human Spontaneous Preterm Labor

Among the immune cells, maternal PD1+ CD8 T cell subsets were less abundant in term laboring compared to term non-laboring women. Among the non-immune cells, PD-L1+ maternal (stromal) and fetal (extravillous trophoblast) cells were less abundant in preterm laboring compared to term laboring women.