Placental Histology and Perinatal Outcomes in Women Who Delivered at Term With and Without Gestational Diabetes Mellitus at Bungoma County Referal Hospital in 2017

Abstract

Background: Gestational Diabetes Mellitus (GDM) is a crucial underdiagnosed and poorly managed disease in our set up. It is a significant cause of perinatal morbidity, mortality, and poses health risks to the future child. The adverse outcomes are primarily linked to placental changes that alter perfusion and diffusional efficiency. These placental histomorphometric changes are associated with GDM. The study sought to study histomorphometric features following the Amsterdam Placental Workshop Group recommendations to generate local data that could be used for risk stratification so as to tailor ANC follow up for GDM women. Research question; what are the differences in placental histology and perinatal outcomes in women with and without GDM delivering at term at BCRH in 2017. Objectives: To compare the differences in the placental histological and perinatal outcomes in women with and without GDM delivering at term at BCRH in 2017. Materials and methods: This was a nested case control study; as computed by formulae a sample size of 19 GDM and 57 non GDM placentae as cases and controls respectively. My study was nested in a larger on-going study which seeks to develop a neonatal infection diagnostic tool by use placental tissue. The samples were drawn from Bungoma County Referral Hospital and analysis done at the Basic, Clinical and Translational (BCT) research laboratory located in the Department of Human Anatomy, University of Nairobi. Formalin-fixed paraffin-embedded placental tissues were obtained from the placental repository; selected according to the study’s inclusion and exclusion criteria then processed for microscopy. The general histology organisation was analysed by light microscopy after staining. Histomorphometry including diameter and cross sectional surface area of the terminal villi were conducted using Image J analysis. Perinatal outcome was assessed by birth weights. The data was then analysed using SPSS version 26 into means, standard deviation, and P values. A P value of ˂0.05 was deemed significant. Results: The socio-demographic features of the two groups were largely comparable, with most women being multiparous married and high school leavers. The mean age for the cases was 27 years compared to the control which was 28 years. Neonatal weights were significantly higher in the cases 3666g compared to 2789g in the cases (p-value of 0.001), further the neonatal placental weight ratio was significantly increased in cases 1:6.91 compared to 1:5.32(p-value of 0.001). Histologically we observed more oedema in the cases 53% compared to 2% in the controls, increased cytotrophoblast in the cases 33% to none in the controls, villus infarcts were increased in the cases 40% compared to nil in the controls, significant peri villus fibrinoid deposition in the controls 27% to 4% in the cases (P Value of < 0.03). The cases had more chorangiosis 27% compared to 2 % in the controls, furthermore 33% of the cases had vessels centrally placed in the villus than controls 0% Histomorphometrically the cases had significantly larger terminal villus, mean size of 145.18μM (±2SD) in the cases compared to 69.58 μM in the controls (P value of< 0.001), with significantly lowed vascularization quotient of 0.20 compared to 0.40 in the controls(P value of<0.001). These findings were all in keeping with maternal vascular malperfusion (MVM) an Amsterdam Placental Workshop Group (APWG) pattern. Conclusion Our study showed that maternal-vascular malperfusion (MVM) occurred more frequently in the GDM group than in the non-GDM, with heavier neonates in the GDM group compared to the non-GDM. Recommendation We recommend tight antenatal glycaemic control to prevent MVM. Further we recommend routine immediate postnatal placental sampling and microscopy for all women with GDM; this will enable subsequent pregnancy risk stratification in women with histologically confirmed MVM. Future work in this area could focus on clinical, sonographic and molecular correlates to the pathognomic lesions with the view of being able to prenatally diagnose and mitigate