“…The two known major risk factors of ROP are extreme prematurity (1–5) and hyperoxia (3,6). Other risk factors for ROP have been previously reported, including hyperglycemia (4), apnea (6), hypoxia (7), bacterial and fungal late‐onset sepsis (1,8), multiple blood transfusions (3,9,10), metabolic acidosis in animals (11,12), hypercapnia in animals and humans (13), small for gestational age (SGA) status (5,14), male gender (5), genetic factors (15), overexpression of vascular endothelial growth factor (VEGF) (16–19) and low serum level of insulin growth factor‐1 (IGF‐1) (7). In addition, severity of respiratory distress syndrome (RDS) was shown to be significantly associated with development of ROP (9).…”