Placental Pathological Lesion Categories Associated Lesions
Maternal vascular malperfusion 1.       Retroplacental hematoma/hemorrhage
2.       Focal, multifocal, or diffuse parenchymal infarction
3.       Intraparenchymal thrombus
4.       Accelerated villous maturity
5.       Terminal villous hypoplasia (diffuse)
6.       Increased syncytial knots (Tenney-Parker changes)
7.       Decidual vasculopathy
Fetal vascular malperfusion 1.       Marginal insertion of umbilical cord
2.       Velamentous insertion of umbilical cord
3.       Furcate insertion of umbilical cord
4.       Single umbilical artery
5.       True knot (one or more)
6.       Increased cord coiling (>3 coils/10 cm)
7.       Decreased cord coiling (≤ 3 coils/10 cm)
8.       Avascular villi, focal, multifocal, or diffuse
9.       Villi with stromal-vascular karyorrhexis
10.   Chorangiomas
11.   Chorangiomatosis
12.   Chorangiosis
13.   Edema (hydrops)
Inflammatory lesions involving maternal compartment 1.       Acute chorioamnionitis, placental membranes
2.       Acute chorioamnionitis, chronic plate
Inflammatory lesions involving fetal compartment 1.       Umbilical cord acute arteritis (1 vessels)
2.       Umbilical cord acute arteritis (≥2 vessels)
3.       Umbilical cord acute phlebitis present
4.       Umbilical cord acute vasculitis (all vessels) present
5.       Acute funisitis present
6.       Chorionic plate acute vasculitis
7.       Villitis
8.       Acute villitis
Immune/Idiopathic
Perivillous fibrin deposition Intervillous fibrin deposition Chronic intervillositis