Increased Syncytial Knot Formation

Abstract

Syncytial knots are a common histologic feature of the placenta. This overarching term includes four specific subtypes of syncytial knots, including syncytial sprouts, true knots, false knots and syncytial bridges. Wave-like syncytial knots represent a specific architectural arrangement of syncytial knots generally found at earlier gestational ages. Increased syncytial knots have long been associated with adverse pregnancy outcomes, including preeclampsia and fetal growth restriction, and are a defining feature of maternal vascular malperfusion. More specifically, increased syncytial knots appear to arise in response to hypoxic or hypoxia-reperfusion injury to the placenta.