The pro-life movement, also known as the anti-abortion movement or the right-to-life movement, in the United States contains elements opposing elective abortion on both moral and sectarian grounds and supports its legal prohibition or restriction. Advocates generally argue that human life begins at conception and that the human zygote (or embryo or fetus) is a person and therefore has a right to life. The pro-life movement includes a variety of organizations, with no single centralized decision-making body. There are diverse arguments and rationales for the pro-life stance. Some anti-abortion activists concede arguments for permissible abortions in exceptional circumstances such as incest, rape, severe fetal defects or when the woman's health is at risk.