Hypothesis: ELGANs at risk for severe ROP will have different pattern of gene expression specifically related to the Notch signaling pathway, as has been previously shown in animal models. We will: a) Examine cord blood, cord tissue, and placental tissue to compare the gene profile of VEGF and Notch signaling pathways among infants who develop severe ROP and those who do not; and b) Determine whether NSAIDs and/or Caffeine will confer protective benefits on Notch/Dll4 signaling and prevent the development of severe ROP.