Abstract
Background: The placenta is a pivotal medium for physiological exchanges between the maternal and fetal circulations. However, diabetic insults early in gestation can influence the placental barrier, potentially impacting fetal development and outcomes. This study sought to understand the histological changes in the placentae of gestational diabetes mellitus (GDM) cases, highlighting the significance of these alterations on fetal health.

Aims and Objectives: The primary aim of this research was to elucidate the histological changes present in the placentae of women diagnosed with GDM. Furthermore, the study sought to determine the implications of these changes on the standard placental anatomy and its associated functionalities, thereby assessing potential impacts on fetal development and outcomes.

Materials and Methods: A case–control study was conducted at MES Medical College, Perinthalmanna, Kerala, from October 2014 to December 2018. Inclusion criteria considered pregnant women aged 19–38 years diagnosed with GDM, among other factors. Exclusion criteria weeded out pre-diagnosed diabetes cases, unclear glycemic statuses, and a range of pregnancy complications. Placentae samples underwent meticulous histological and histochemical analyses, focusing on key histological features, including syncytiotrophoblastic knots, vasculosyncytial membranes, and chorangiosis.

Results: Significant histological variations were observed in GDM cases compared to controls. Notably, there was an increased formation of syncytial knots and reduced vasculosyncytial membranes in GDM placentae. In addition, chorangiosis was more prevalent, suggesting potential chronic prenatal hypoxia. Marked thickening of the syncytiotrophoblast basement membrane, villous edema, and fibrinoid necrosis were other pertinent findings in GDM cases, each with statistical significance (P < 0.001).

Conclusion: The findings underscore the profound histological changes in the placenta associated with GDM, emphasizing the need for comprehensive maternal care and monitoring. These alterations can compromise fetoplacental transport and may have long-term implications on fetal health, highlighting the critical role of timely GDM diagnosis and intervention.

Key words: Gestational Diabetes Mellitus; Placental Histology; Syncytial Knots; Vasculosyncytial Membrane; Chorangiosis; Placental Anomalies; Fetal Outcomes