Contrary to the narrative being pushed by many media outlets, authoritative medical studies show that IUDs sometimes terminate living, viable human embryos. For example, the medical textbook "The Developing Human: Clinically Oriented Embryology" explains that fertilization marks the "beginning of a new human being (i.e., an embryo)," and the American Journal of Obstetrics and Gynecology states that "both prefertilization and postfertilization mechanisms of action contribute significantly to the effectiveness of all types of intrauterine devices."