[Ethical aspects of embryonic stem cell research]

Research using embryonic stem cells raises a variety of ethical questions, which will be explored in this article. At the core of the ethical controversy is the question of the status of the embryo and its availability for research. A range of countries have approved the use of "supernumerous" embryos from in-vitro fertilization. But ethical problems also arise in reproduction medicine, the informed consent of affected couples, and the targeted production of embryos and egg cell donation for research. The author discuss some of these neglected issues and develops suggestions for comprehensive ethical reflection.