An Objective Histopathological Scoring System for Placental Pathology in Pre-Eclampsia and Eclampsia

Background and objective
Pre-eclampsia and eclampsia are common complications in pregnancy, and they lead to uteroplacental vascular insufficiency. More than 38% of pregnant women succumb to seizures without meeting the clinical criteria for pre-eclampsia or eclampsia. This highlights the importance of a confirmatory diagnosis of pre-eclampsia or eclampsia using the histopathological changes seen in the placenta. Hence, the present study aimed to validate an objective histopathological scoring system of the placenta for an appropriate diagnosis of pre-eclampsia or eclampsia.

Material and methods
In this prospective study spanning two years, 50 cases of pre-eclampsia/eclampsia and 50 control subjects with normal placenta were included. The histomorphological changes in the placenta were examined for both groups and a scoring system was formulated to assess the severity of pre-eclampsia/eclampsia syndrome. A maximum score of 2 and a minimum score of 0 was assigned for maternal floor infarcts, calcification, villous basement membrane thickening, and fibrin deposition. Syncytial knots were assigned a minimum score of 0 and a maximum score of 1. The association of various placental histopathological variables with a clinical diagnosis of pre-eclampsia, eclampsia, and control was analyzed using the chi-squared/Fisher’s exact test. A one-way analysis of variance (ANOVA) test was used for comparing objective histopathological scores between pre-eclampsia, eclampsia, and control groups. A p-value of less than 0.05 was considered to be statistically significant.

We found a significant association between each histopathological parameters of the placenta, including fibrin deposition, maternal floor infarction, calcification, villous basement membrane thickening, and syncytial knots, and clinical diagnosis of pre-eclampsia, eclampsia, and control groups. A median score of 2 significantly correlated with the normal group, while median scores of 4 and 6 correlated with pre-eclampsia and eclampsia respectively.

This comprehensive scoring system can be a basis for validating reporting patterns of the placenta in pre-eclampsia and eclampsia patients, as well as other disorders related to maternal uteroplacental insufficiency.