Is it necessary for the husband to know what happened to him so he can choose between pardon or blood money?

A woman is not obligated to inform her husband that she aborted their child. She should conceal her act, seeking Allah's concealment, and pay the child's blood money (diyya) to its heirs without informing them that it is the blood money for their child. She also owes the expiation for accidental killing, which is freeing a believing slave or fasting two consecutive months, along with sincere repentance. There is no retaliation (qisas) against her because she is the child's mother. The child's heir is its father, who was born on his bed, for "the child is for the bed."