What are the characteristic placental pathology findings in preeclampsia?

From the Guidelines

Preeclampsia is characterized by several distinctive placental pathology findings, including placental insufficiency, shallow trophoblast invasion, and inadequate remodeling of spiral arteries, as noted in studies such as 1. The most prominent feature is placental insufficiency, manifested as a smaller-than-expected placenta with evidence of maternal vascular malperfusion. Some key features of placental pathology in preeclampsia include:

• Shallow trophoblast invasion and inadequate remodeling of spiral arteries, which remain narrow and high-resistance instead of becoming wide, low-resistance vessels, as discussed in 1.
• Acute atherosis in decidual vessels, characterized by fibrinoid necrosis, foam cells, and perivascular lymphocytic infiltration.
• Placental infarcts are common, appearing as well-demarcated areas of villous necrosis.
• Intervillous thrombosis and retroplacental hemorrhage may be present.
• Microscopically, there is increased syncytial knot formation, villous agglutination, increased perivillous fibrin deposition, and accelerated villous maturation. These changes reflect the hypoxic environment resulting from inadequate maternal blood flow, as noted in 1. In severe cases, particularly with early-onset preeclampsia, these findings are more pronounced and widespread. These pathological changes explain the clinical manifestations of preeclampsia, as the ischemic placenta releases factors into maternal circulation that cause systemic endothelial dysfunction, leading to hypertension, proteinuria, and other systemic complications.

From the Research

Characteristic Placental Pathology Findings in Preeclampsia

The characteristic placental pathology findings in preeclampsia include:

• Decidual vasculopathy (DV), which is characterized by fibrinoid necrosis and foamy macrophages within the vessel walls 2, 3
• Perivascular lymphocytic infiltration and foam cell incorporation within the vessel wall, also known as acute atherosis 3, 4
• Endothelial proliferation with detachment, remodeling of the media with smooth muscle loss, and variable degrees of fibrin deposition 4
• Accelerated villous maturity and perivascular inflammatory cell infiltration 2

Location and Morphological Features of Decidual Vasculopathy

The location and morphological features of decidual vasculopathy include:

• Location in the decidua basalis, which is correlated with increased perinatal mortality 5
• Presence of thrombosis, which is also correlated with perinatal mortality 5
• Foam cell infiltration, which does not increase correlation strength with adverse outcomes 5
• Endothelial injury, fragmentation, and repair with incorporation of endothelial components into the vascular wall 4

Clinical Correlations of Decidual Vasculopathy

Decidual vasculopathy is correlated with:

• Higher diastolic blood pressure, shorter gestational age, lower birth weight, and lower umbilical artery pH 2, 5
• Increased placental pathology, including accelerated villous maturity, infarction, and hematoma formation 2, 5
• Adverse maternal and fetal outcome, including perinatal mortality 5
• Preeclampsia with small for gestational age (SGA), which is the most severely affected group 4