How is the age of the fetus calculated to determine if it has exceeded forty days, after which abortion is prohibited, and is abortion permissible after this period if the mother is medically unable to carry the pregnancy to term?

It is impermissible to abort a fetus under any circumstances, even if it is a zygote that has not exceeded forty days, according to the preponderant opinion. Whoever aborts it after the ensoulment must pay the blood money (diyah) and perform expiation by fasting for two consecutive months. A woman can determine the age of the fetus by consulting specialized doctors.