It is usually normal for a 40 day old baby to sleep for 6 hours a night.
Since the neurological development of 40-day-old babies is incomplete, they sleep more every day, which is a kind of protective behavior. Generally speaking, during the daytime the baby sleeps for about 1~2 hours at a time, and at night the sleep time is also relatively longer, which may be maintained at about 4~6 hours, so there is no need to worry too much.
Sleep is very important for 40-day-old babies to ensure the development of the brain, promote the perfection of the nervous system, and lay the foundation for subsequent healthy growth, so don’t disturb it easily.
In addition, you should pay close attention to your baby’s physical state during sleep and wakefulness, and if there is a prolonged period of mental depression, you should be more vigilant and seek medical checkup if necessary.