Table 1 Histological stages of the fetal immune response towards chorioamnionitis [32, 33]
From: Human perinatal immunity in physiological conditions and during infection
Histological stage | Characteristics |
|---|---|
1 | Stage 1 is defined by neutrophils in the chorionic vessels (chorionic vasculitis) and/or umbilical vein (umbilical phlebitis). |
2 | Stage 2 is reached when neutrophils enter the wall of the umbilical artery (umbilical arteritis), with or without minor degrees of extravasation into Wharton’s jelly. |
3 | Stage 3 is heralded by organization of neutrophils in Wharton’s jelly into arc-like bands surrounding one or more umbilical vessels (concentric umbilical perivasculitis or necrotizing funisitis). |