The cardiovascular system is the first functional organ system to develop in the vertebrate embryo, reflecting its critical role during normal development and pregnancy. This Adverse Outcome Pathway focuses on the regulation and disruption of vasculogenesis-angiogenesis during embryonic development via disruption of the Vascular Endothelial Growth Factor (VEGF) signaling pathway. This pathway is a critical regulatory system for assembly of embryonic blood vessels. Genetic studies have shown that perturbing the VEGF signaling system can invoke varying degrees of adverse consequences, ranging from congenital angiodysplasia to fetal malformations and embryolethality. This AOP is referred to as AOP 43 in the Collaborative Adverse Outcome Pathway Wiki (AOP-Wiki).