Placental pathology in early-onset fetal growth restriction: insights into fetal growth restriction mechanisms

Background: Early-onset fetal growth restriction (FGR), an identifiable variant of FGR, exhibits divergences in its severity, management, and placental pathologies when juxtaposed with late-onset FGR. The objective of this cross-sectional investigation was to scrutinize placental pathologies in pregnancies afflicted by early-onset FGR, emphasizing a comparative analysis between cohorts with and without preeclampsia (PE). Patients, Materials and Methods: The study encompassed a cohort of 85 expectant mothers who received a diagnosis of early-onset FGR. Rigorous histopathological (HP) and immunohistochemical (IHC) assessments were conducted on the placentas. Comparative analyses were performed, distinguishing between individuals diagnosed with both PE and early-onset FGR, and those presenting normotensive early-onset FGR. Results: HP analysis unveiled a multitude of shared placental lesions, encompassing retroplacental hemorrhage, expedited villous maturation, infarctions, and calcification-associated fibrin deposits. IHC investigations displayed affirmative immunoreactivity for anti-hypoxia-inducible factor (HIF) and anti-vascular endothelial growth factor (VEGF) antibodies within the placental infarcted villitis. Moreover, noteworthy variances in placental measurements and distinctive lesions were discerned when comparing the PE and early-onset FGR cohort with the normotensive group. Conclusions: Maternal malperfusion emerged as a pivotal determinant linked to placental lesions in pregnancies affected by early onset FGR. Remarkably, the occurrence of infarctions, specifically delayed infarctions, exhibited a noteworthy correlation with PE. These findings accentuate the significance of pursuing additional research endeavors aimed at unraveling the intricate mechanisms governing maternal malperfusion and its consequential influence on placental health in the context of early-onset FGR, with particular attention to the interplay with PE.