Introduction/Background: Gestational diabetes mellitus (GDM) is the most common complication during pregnancy. GDM is leading to an elevated risk for the development of cardiovascular diseases both in the mother and the child in later life. Previous studies have identified fatty acid-binding protein 4 (FABP4) as a prime candidate involved in the pathophysiology of GDM. Indeed, women with GDM exhibit elevated blood levels of FABP4, suggesting its potential role as a biomarker for endothelial dysfunction and cardiovascular risk assessment in GDM. Research Question/Hypothesis: Does FABP4 affect the function of human endothelial cells from patients with GDM? Goals/Aim: Our aim is a better understanding of the role of FABP4 in fetal endothelial dysfunction of patients with GDM and the development of potential therapeutic strategies. Methods/Approach: Primary human umbilical vein endothelial cells (HUVECs) were isolated from umbilical cords obtained from normoglycemic and GDM pregnancies. Total mRNA from HUVECs was used for bulk RNA sequencing to compare gene expression pattern. HUVECs were subjected to functional analyses assessing proliferation, migration, NO and insulin signaling. Finally, human endothelial cells were exposed to high laminar flow (30 dyn/cm 2 ) or simvastatin (10 nM) treatment to investigate their impact on FABP4 expression and endothelial function. Results/Data: Bulk RNA sequencing data analysis revealed FABP4 as a gene overexpressed in GDM HUVECs compared to normoglycemic controls. Gene set enrichment analysis showed in addition an enrichment of genes involved in angiogenesis and Notch signaling pathways in human endothelial cells from GDM patients. GDM HUVECs had a significantly higher wound healing capacity compared to normoglycemic controls. The PI3K/AKT/mTOR pathway was enriched in GDM HUVECs. GDM HUVECs displayed impaired activation of AKT and eNOS (expression and phosphorylation) after stimulation with insulin, suggesting a possible insulin resistance. Finally, subjecting HUVECs to high laminar shear stress or simvastatin treatment caused a reduction of FABP4 mRNA expression and an increase of eNOS expression, indicating potential therapeutic strategies to improve endothelial function. Conclusions: We provided evidence that FABP4 could be involved in fetal GDM-induced endothelial dysfunction. High laminar shear stress and medications activating eNOS signaling could protect the endothelium against the negative impact of FABP4 in GDM.