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n. pl. pre-em·bry·os
A fertilized ovum up to 14 days old, before it becomes implanted in the uterus.

pre-em′bry·on′ic (-ŏn′ĭk) adj.


(Biology) the structure formed after fertilization of an ovum but before differentiation of embryonic tissue
References in periodicals archive ?
Scientifically, the term pre-embryo makes very little sense," Suadeau said.
On the first issue, are these embryos human life--well, one researcher told me he believes this five-day-old cluster of cells is not an embryo, not yet an individual, but a pre-embryo.
It cannot be that the pre-embryo is worthy of any protection--in which case, the current abortion-by-choice regime would be untenable; and, as mentioned, most pre-embryos die in any case because they simply fail to find a hold, and not even the most high-minded ethics elder has ventured into suggesting that we should attempt to protect these poor doomed microscopic entities.
We base our decision in this case solely on the contractual rights of the parties under the pre-embryo cryopreservation contract.
A summary of the findings indicates that respondents were interested in more information about the type of research pre-embryos would be used for (82%), felt the government should play a role in pre-embryo research (58%), believed that unused pre-embryos should be used to further medical science, if possible (74%), and would want to designate how their pre-embryos would be used for research (78%).
A term pre-embryo, in vogue a few years ago among scientists and fertility clinics, had served to soften opposition, at least among parents, to freezing or destroying embryos or using them for research.
The pre-embryo is defined as the entity that exists prior to the appearance of the primitive streak at day fourteen.
While the moral status of the human pre-embryo -- frozen or not -- is murky at, best, clearly someone desires this entity and such claims are actionable.
While the account of Daly's choice as a pre-embryo to be a radical feminist philosopher is probably meant to be both figurative and amusing, it also, I think, reveals Daly's understanding of human will as ultimately determinative and triumphant.
Effect of a woman's smoking status on oocyte, zygote, and day 3 pre-embryo quality in in vitro fertilization and embryo transfer program.
Before these fourteen days are completed, the pre-embryo lacks "the appearance of a single primitive streak" which establishes the group of cells as an individual human.
128) Notably, however, there is "a different balance when the stored pre-embryo may be the mother's last chance to be a genetic mother .