Inclusion Criteria:  Cases group:  The presence of a sentinel hypoxic event immediately before or during delivery History of fetal distress (bradycardia, late decelerations, absence of heart rate variability). Need for neonatal resuscitation at delivery One-min Apgar score <3 or 5-minApgar score<7 Metabolic acidosis (BE > 10 in cord blood) Cardiocirculatory instability (CCI), clinical indications of hypoxic-ischemic encephalopathy (HIE) and multiple organ involvement (MOI).  Control group:  Newborns who were delivered normally after uncomplicated pregnancy. None of them have clinical nor biochemical signs of asphyxia.  Exclusion Criteria:  Newborns who do not fulfill the above criteria. Newborns with congenital heart diseases and perinatal hemolytic anemia or congenital liver affection. Whose parents refuse to participate in the study. Cases above 4 days old. Preterm neonates (less than 37 weeks).