Normal HR ; RR
The normal range for heart rate
is 100-160 for a 3 week old, although if baby really upset crying
hard up to 180 would not be unusual.
Respiratory rate ranges from low 20's to 60. # week old babies also still have a percentage of periodic breathing, a normal breathing pattern where they breath very rapidly and then slow way down and almost look like they are not breathing and then speed up again.