Most common cause of convulsion on the First day of life in a newborn is –

Neonatal seizures The most prominent feature of neurological dysfunction in the neonatal period are seizures. The five major causes of neonatal seizures are - Hypoxic ischemic enceplialopathy (hypoxia, anoxia) → most common        Hypocalcemia  Hypoglycemia Meningitis Polycythemia