Histological and Morphological Study of the Placenta in Gestational: Pregestational Diabetic, and Normal Women’s

Abstract

This study was aimed at comparing the morphometric and histological features of the placenta in gestational diabetes mellitus (GDM), pre-gestational diabetes mellitus (PGDM), and non-diabetic normal pregnant women. Twenty-four placentas were obtained from non-diabetic pregnant women (control group), ten from women with GDM, and ten from PGDM women. Segments from the central part of the placenta were taken and processed for paraffin blocks, sectioned, and stained with H&E, Masson trichrome, and periodic acid-Schiff. The results of morphometric measurement revealed that the mean weight and diameter of GDM and PGDM placentae were significantly higher than in the control; placental thickness was a significant increase in PGDM; the number of cotyledons and fetal weights showed no significant difference in all these groups; the fetoplacental ratio was significantly higher in the PGDM; discoidal placenta shape, followed by irregular, oval, and kidney as the most common shapes recorded in these groups; the central umbilical cord insertion was most common in all three groups; followed by noncentral (eccentric) and marginal insertions. Diabetes caused several histopathological changes in the placenta, including an increase in the number of different sizes of villi with a decrease in the intervillous spaces, an increase in the: number of big syncytial knots, and fibrinoid necrosis; chronogenesis in the intervillous spaces and villous capillary congestion. Diabetic groups showed the presence of dense collagen fibers within the villous stroma (villous stromal fibrosis) and around fetal blood capillaries. GDM showed a mild thickening of the basement membrane (BM) of chorionic villi and a mild increase in the collagen in the villous stroma. While PGDM showed a moderate increase in the BM of syncytiotrophoblast and villous stroma and mild thickening of the BM of capillary blood vessels. In conclusion, both GDM and PGDM caused adverse effects on the histological and morphometrical features of the placenta. Keywords: Placenta; Diabetes Mellitus; Morphometric analysis; Histopathology, Masson trichrome stain; Periodic acid shift reaction. DOI: 10.7176/JBAH/13-6-03 Publication date: April 30 th 2023