Should the biological definition of human embryo include a developmental time point?
It has been previously argued that the potential for continued development should be a key consideration for any definition of embryo (Latham and Sapienza, 2004). The discussion presented in this paper fully supports this view. However, it is questionable whether it is possible to define human embryo without making some reference to a developmental point in time. Another approach to the development of a biological definition of human embryo may be one that does include a reference to a specific developmental time point, but in the context of the potential for continued development. The term human embryo is not applicable before the completion of fertilization of a human oocyte by a human sperm (i.e. syngamy), because this is when the new genome of the new individual is created. Prior to syngamy the maternally and paternally inherited genomes exist as two separate genomes. A definition of human embryo based on syngamy excludes reproductive technologies that do not involve the fertilizat
