An abortion is the removal or expulsion of an embryo or fetus from the uterus, resulting in or caused by its death. This can occur spontaneously as a miscarriage, or be artificially induced by chemical, surgical or other means. "Abortion" can refer to an induced procedure at any point during human pregnancy; it is sometimes medically defined as either miscarriage or induced termination before the point of viability. Throughout history, abortion has been induced by various methods. The moral and legal aspects of abortion are subject to intense debate in many parts of the world.