Inclusion Criteria:  neonates who are admitted in the neonatal intensive care unit in Assiut University children hospital suffering from RDS.  Exclusion Criteria:  The newborn will be excluded from the study when his/her parents refuses to participate or when the neonate presented with one or more of the following:  Multiple congenital anomalies Severe infection Inherited metabolic disorders Any systemic disorder (hepatic, renal, cardiovascular, and endocrinal, ...etc) Malignancies Hypoxic Ischemic Encephalopathy