Why newbirn baby have high wbc count than adult?

Normally: Newborns have significantly higher white counts in the immediate newborn period. Probably because of the Epinephrine effect associated with the stress of delivery. This is a normal response.

Stress hormones: A newborn does have stress during labor & delivery. As part of that stress, the body releases self made cortisol and epinephrine.These by themselves can double the white blood cell count by moving cells off their resting place on the walls of blood vessels into the circulating stream.