Question

why do baby cries soon after the birth

Answer 1

they cry because of this is necessary for their survival while in the womb the baby breathes through the umbilical chord and once out the baby must breath on its own. and also crying helps in also breathing properly

Answer 2

Before birth the baby in the womb gets oxygen and sends away carbon dioxide through the umbilical cord connecting to the mother.  Lungs do not function yet.

Before birth the baby in the womb gets oxygen and sends away carbon dioxide through the umbilical cord connecting to the mother.  Lungs do not function yet.

After birth the lungs have to be cleared and free passage of air from mouth/nose through the throat is to be done.  By crying  the baby clears the secretions, amniotic fluids from lungs and nose. Then air flows freely in and out of lungs.

In some cases, if the baby does not cry then doctors hold the baby upside down and pat on the back to stimulate this clutter-clearing action.  Or, doctors may rub on the feet or back to stimulate through the nervous system in the baby to cry.

The cry helps baby in beginning to breath in and out as a normal human being at the start of their life.   Babies also cry naturally because they are hungry and have not taken in food for some time, they exhaust their energy during the birth process, and also because they feel quite a different environment around them.