Intervillous Thrombus Is Independently Associated With Placental Infarct and Single Umbilical Artery as well as Fetal Inflammatory Response: Implication of Fetal Vascular Flow in Pathogenesis

Abstract

Background:

Intervillous thrombi (IVT) is one of the most common pathology findings during placental examination. The etiology and clinical significance of IVT are controversial.

Materials and Methods:

We previously collected placental data with fetal birth data and maternal pregnancy characteristics, and we examined IVT in the context of maternal, fetal, and placental pathology.

Results:

A total of 3119 placentas with fetal birth and maternal pregnancy characteristics were examined, and IVT was found in 644 placentas (20.6%). IVT was statistically associated with advanced maternal age (P = .01) and clinical preeclampsia (P = .02). IVT was significantly associated with placental infarcts (P < .01), mural arterial hypertrophy (P = .02) as well as placental abruption (P < .01). In addition, IVT was significantly associated with velamentous cord insertion (P < .01). Regression analysis demonstrated the persistence of association between IVT placental infarct, in addition to 2 vessel cord (SUA) and fetal inflammatory response (FIR, acute funisitis/fetal vasculitis).

Conclusion:

Our data showed that IVT was independently associated with placental infarct, single umbilical artery, and fetal inflammatory response after regression analysis. The association of IVT with single umbilical artery and fetal inflammatory response points to fetal blood flow as potential pathogenic basis, providing new insight into pathogenic mechanisms and clinical significance.