Analysis of the relationship between placental histopathological aspects of preterm and term birth

This study aims to establish a correlation between placental histopathological and immunohistochemical (IHC) changes and preterm birth with fetal growth restriction (FGR, formerly called intrauterine growth restriction - IUGR).

This prospective study was performed on a group of 30 parturients, with singleton gestation, of which 15 patients gave birth at term, and the other 15 patients gave birth prematurely. After the statistical correlation of the clinical and demographic data with premature birth (PB) and term birth (TB), we performed histological and IHC research on the respective placentae. To observe normal and pathological microscopic placental structures, we used the Hematoxylin-Eosin (HE) and Periodic Acid Schiff-Hematoxylin (PAS-H) classical stainings, but also special immunostaining with anti-cluster of differentiation 34 (CD34) and anti-vascular endothelial growth factor (VEGF) antibodies.

We found a statistically significant difference between the TB∕PB categories and the age of the patients, their antepartum weight, the weight of the newborns, and the placenta according to the sex of the newborn. Histological analysis revealed in the case of TB, small areas of perivillous amyloid deposition, with the significant extension of these areas both intravillous and perivillous in the case of PB. Massive intravillous calcifications, syncytial knots, and intravillous vascular thrombosis were also frequently present in PB. With PAS-H staining were highlighted the intra∕extravillous vascular basement membranes, but especially the massive fibrin deposits rich in glycosaminoglycans. By the IHC technique with the anti-CD34 antibody, we noticed the numerical vascular density, higher in the case of TB, but in the case of PB, there were large areas of placental infarction, with a lack of immunostaining in these areas. Through the anti-VEGF antibody, we observed the presence of signal proteins that determined and stimulated the formation of neoformation vessels in the areas affected by the lack of post-infarction placental vascularization. We observed a highly significant difference between placental vascular density between TB∕PB and newborn weight, sex, or placental weight.

Any direct proportional link between the clinical maternal-fetal and histological elements yet studied must be considered. Thus, establishing an antepartum risk group can prevent a poor pregnancy outcome.