Is the death of a fetus after its birth, following the mother's attempts to abort it through self-exertion and lack of food, considered "killing a soul," and what is the expiation for that?

The woman must repent to Allah Almighty for her transgression. She is not obligated to pay blood money (diyah) or expiation (kaffarah (definition)) if the fetus was born healthy and lived for a period, then died, because the death of the fetus in this case was not due to her action. The guarantee (of compensation) applies if it is known that its death was due to the blow. If the fetus was born alive and healthy and did not die from the transgression, then there is no guarantee on the assailant.