Placental diabesity: placental VEGF and CD31 expression according to pregestational BMI and gestational weight gain in women with gestational diabetes

Purpose The aim of this study is to investigate the placental expression of VEGF and CD31 in pregnancies complicated by gestational diabetes (GDM) and the influence of pregestational BMI and gestational weight gain (GWG) on this expression. Methods We prospectively enrolled pregnant women with diagnosis of GDM and healthy controls who delivered in our Center between December 2016 and May 2017. Patients were grouped according to the presence of GDM and we compared pregnancy characteristics, placental VEGF and CD31 expression between the cases and controls. Immunochemistry analysis was performed to assess biomarkers positivity. Positivity of biomarkers was assessed in a dichotomic fashion with positivity set at 5% for VEGF and 1% for CD31. Results 39 patients matched inclusion criteria, 29 (74.3%) women with GDM and 10 (25.7%) healthy controls. Immunochemistry analysis showed that VEGF was more expressed in placentas from women with GDM compared to controls (21/29, 72.4% vs 2/10, 20%; p = 0.007), and CD31 was more expressed in placentas from women with GDM compared to controls (6/29, 20.7% vs 0/10, 0%; risk difference 0.2). VEGF positivity was associated with the presence of GDM (aOR 22.02, 95% CI 1.13-428.08, p = 0.04), pregestational BMI (aOR 1.53, 1.00-2.34, p = 0.05) and GWG (aOR 1.47, 95% CI 1.03-2.11, p = 0.03). CD31 positivity was associated with the pregestational BMI (aOR 1.47, 95% CI 1.00-2.17, p = 0.05) and with the gestational weight gain (aOR 1.32, 95% CI 1.01-1.72, p = 0.04). Conclusion Pregnancies complicated by GDM are characterized by increased placental expression of VEGF and CD31, and the expression of these markers is also independently associated to maternal increased pregestational BMI and GWG, defining the concept of "placental diabesity".