Final answer:
Neonatal Abstinence Syndrome signs usually appear within 72-96 hours after birth, as the newborn adjusts to life outside the womb without the placenta's support.
Step-by-step explanation:
Neonatal Abstinence Syndrome (NAS) is a condition that affects newborns who were exposed to addictive substances while in the womb. The signs of NAS typically become apparent within 72-96 hours after birth, although they can sometimes be seen as early as 24 hours.
During the neonatal period, which spans from birth to the 30th day of life, newborns must adjust to dramatic changes in their environment. They no longer rely on the placenta for nutrition and oxygen and instead must breathe, eat, and regulate their own body temperature. These adjustments are complicated if the newborn is dealing with withdrawal symptoms from substances they were exposed to in utero.