“CORRELATION BETWEEN CLINICAL AND HISTOPATHOLOGICAL FEATURES IN PRETERM AND TERM BIRTH PLACENTA USING HISTOCHEMICAL AND IMMUNO HISTOCHEMICAL METHODS”

Abstract

Introduction: Preterm birth is a complex condition caused by multiple risk factors and can lead to long-term health problems in the child. Examination of the placenta provides valuable diagnostic information to help determine the underlying cause of preterm birth. Aim: This study aimed to describe and compare the histo-morphological changes in preterm and term placentas, correlating gross and microscopic findings with maternal and fetal risk factors associated with preterm birth. Specific objectives included correlating gross and microscopic structural and vascular placental changes with coexisting maternal and fetal clinical features, and establishing a correlation between histological findings using special stains (PAS, Masson's trichrome, reticulin, and Congo red) and immunohistochemical markers (VEGF and CD34) in preterm placentas. Materials and Methods: A case-control study was done on a total of 64 samples, which were collected in the study period of October 2024 to February 2026 in SRM Medical College Hospital and Research Centre, Chennai, Tamil Nadu, India, with 32 placentas from preterm delivery and 32 placentas from term placenta.. Histological changes in the placenta were assessed in both groups. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS version 28.0 ). For the data follows normal distribution and homogeneity of variance, we used Students t test for 2 groups. The data doesn't follow normality and homogeneity, so we have used the Nonparametric Mann-Whitney U test for comparing two groups. For the association between categorical data, we have used the chi-square test. Descriptive statistics were expressed as mean, standard deviation and percentage.  A p-value <0.05 is considered statistically significant. Results:A total of 64 placentas (32 preterm, 32 term) were analysed. Maternal age was comparable between groups (p = 0.266), while gestational age and birth weight differed significantly (p < 0.001 and p = 0.009). GHTN and hypothyroidism were the most prevalent comorbidities in the preterm cohort (21.9% each). Gross findings were more frequent in preterm placentas but did not reach statistical significance. Histologically, syncytial knots (>50%) were the most significant finding (59.4% preterm vs. 6.3% term; p < 0.001), followed by stromal fibrosis (68.8% vs. 31.3%; p = 0.003) and perivillous fibrin deposition (57.4% vs. 42.6%; p = 0.048). On immunohistochemistry, VEGF expression was significantly elevated in preterm placentas (p = 0.030), while CD34 microvessel density was markedly reduced by 51.1% (82.93 vs. 169.79 vessels/HPF; p < 0.001). Conclusion: The structural characteristics of the placenta play a crucial role in determining pregnancy outcomes. Preterm placentas exhibit distinct histological alterations that can influence neonatal development. Understanding these changes offers valuable insight for anticipating risks and potentially preventing specific morbidities in future pregnancies.