Abnormal placental CD8 T-cell infiltration is a feature of fetal growth restriction and pre-eclampsia.

Key Points: Placental pathological abnormalities are more frequently observed in complicated pregnancies than in healthy pregnancies. Infiltration of CD8 T-cells into the placental villous tissue occurred in both fetal growth restriction and pre-eclampsia, whereas CD79α B-cell infiltration was only apparent with reduced fetal growth. Vascularization, fibrin depositions, macrophage and neutrophil infiltration in the placenta did not differ between healthy and complicated pregnancies.