Why most of the time when mother give birth to a child then the child have lack of blood - Science - Reproduction in Animals

Question

Why most of the time when mother give birth to a child then the
child have lack of blood?

Nikitaa Bhardwaj · Accepted Answer

when a child is born there is a lack of blood as when a child comes
out a large amount of blood also comes out
also the child may have lack of blood because the mother might have
not kept her nutrition complete or would not have taken care of
herself carefully so this might lead the deficiency of blood in
mother or child

Why most of the time when mother give birth to a child then the child have lack of blood?