Can artificial techniques supply morally neutral human embryos for research? Part I. Creating novel categories of human embryos.

Manipulations of the molecular composition and formation of human embryos are posing vital new challenges to traditional concepts of human identity and procreation. Current trends in embryology in particular are reshaping the ethical question of how scientific research should treat experimentally derived embryos. Some investigators have argued that embryos created through artificial means are technologically novel entities that should be exempt from ethical restraints placed on research involving human embryos that come into being through natural processes. These include uniparental embryos derived through cloning or parthenogenesis, as well as multiparental, hybrid-parental, and xenohybrid-parental embryos. If confined to natural means many of these genetic unions could not occur, but through the intervention of technology, it is becoming possible to design and grow strange and unusual forms of embryos, in some cases using human gametes. Regardless of the genetic contributors or the processes used to fertilize and stimulate egg activation, in each case the new embryo represents an individual organism that begins a process of development. We conclude that the prospect of creating or redesigning new human life should be held to a stringent ethical standard of precaution, even higher than that of deciding to destroy existing embryonic life. Accordingly, we urge cautious ethical reflection and broad public discussion prior to deciding whether to permit embryologic research into novel forms of procreative means in nonhuman animals, to be further extended to humans.