Final answer:
Newborn infants typically sleep for 18-20 hours a day, gradually reducing as they grow. By their first birthday, they spend about as much time awake as they do asleep.
Step-by-step explanation:
Newborn infants typically spend most of their time sleeping, as sleep is crucial for their development. During the first few weeks after birth, a newborn baby may sleep for up to 18-20 hours a day, usually in shorter stretches of 2-4 hours at a time. As they grow, their sleep patterns gradually shift, and by their first birthday, infants spend about as much time awake as they do asleep.