Characteristics of chronic placental inflammatory responses (Amsterdam criteria30)
| Chronic inflammatory response | Cellular infiltration |
| Chronic deciduitis | Lymphocytes (CD8+ T cells) Plasma cells Histiocytes Eosinophils |
| Basal chronic villitis | |
| Chronic villitis | |
| Chronic intervillositis | |
| Chronic chorioamnionitis | |
| Eosinophilic/T-cell chronic vasculitis |
Placental inflammatory response could be predicted by maternal serum neutrophil–lymphocyte ratio.24