The Term Pre-Embryo Within the Abortion Debate

It has been suggested by some, primarily within the pro-life movement, that the term pre-embryo should not be used in discussing the stages of pregnancy and fetal development.  Their argument is that the term diminishes the value of the embryo proper as being less than a human person. This could then be used to advocate for abortion and embryo experimentation in the very early stages of pregnancy because an individual person does not yet exist.  For these reasons, the term pre-embryo has become and remains highly contentious.

In its 1987 Instruction, Donum Vitae, the Congregation for the Doctrine of the Faith stated: The terms “zygote”, “pre-embryo”, “embryo” and “foetus” can indicate in the vocabulary of biology successive stages of the development of a human being. The present Instruction makes free use of these terms, attributing to them an identical ethical relevance, in order to designate the result (whether visible or not) of human generation, from the first moment of its existence until birth.[1]

The term pre-embryo and the various discussions related to its use can be traced to 1978 when the first test tube baby, Louise Brown, was born.  The Ethics Advisory Board in the United States felt the need to carefully examine the ethical aspects of artificial reproductive techniques such as in-vitro fertilization.  Their report, published in May, 1979, indicated that the human embryo in its first days of existence is only a growing form of human life, with a high degree of natural mortality and lacking individuality, arguing that the appearance of the primitive streak is one of the basic elements of embryo individualization. The report identified an interval of fourteen days after fertilization during which the human embryo was considered to have no special status, and suggested that most scientific research was ‘ethically’ acceptable. As noted above, the word pre-embryo did not appear in any section of the report.  Neither did any specialist in human embryology form part of the committee.[2]

Soon thereafter, the term pre-embryo was first used in 1979 by a developmental biologist by the name of Clifford Grobstein.[3]  Grobstein was not a human embryologist.  During his career and in his writings the evidence suggests that in 1986 he was a strong believer of the idea that the embryo in its pre-implantation stage had no moral value.[4]

In 1986, the Ethics Committee of The American Fertility Society, published a report entitled Ethical Considerations of the New Reproductive Technologies. During their deliberations it became apparent that a designation was required for the stage of the conceptus for the interval between the end of the process of fertilization until the establishment of biologic individuation – that is, only one unique individual from the development of the fertilized egg.  This timeframe extends from fertilization to the formation of the primitive streak.  Prior to this individuation a fertilized egg could split into twins, triplets, or even more individuals.  The committee selected the term pre-embryo to describe this stage.  At the same time, quite independently, the Volunteer Licensing Authority (established by the Royal College of Obstetricians and Gynaecologists) also selected the same term.[5]

It is generally agreed that the independent yet simultaneous selection of the term pre-embryo by both these organizations was instrumental in bringing it into common usage.

Unfortunately, in spite of this seemingly rational argument for the use of the term pre-embryo, many have continued to argue against its use.

As recently as 1997, in its Cloning Human Beings: Report and Recommendations, the National Bioethics Advisory Commission published the definition of embryo as “the developing organism from the time of fertilization until significant differentiation has occurred, when the organism becomes known as a fetus.”  The term pre-embryo was never used.[6]

In its 1993 edition, The Harper Collins Illustrated Medical Dictionary defines an embryo “as an organism in the earliest stage of development; in a man, from the time of conception to the end of the second month in the uterus.” [7]

Dr. John Eppig, Senior Staff Scientist, a member of the National Institutes of Health Human Embryo Research Panel has stated that, “I would say that among most scientists, the word ‘embryo’ includes the time from after fertilization…” [8]

These references indicate that, even through recent time, prominent authors and institutions continue to use the term embryo from the time of fertilization

Indeed, in 1997, C. Ward Kischer argued that the term pre-embryo has been seized upon and used for the justification for discarding human embryos in abortion procedures, their use in fetal tissue research, and human embryo research.[9]  Other terms equivalent to pre-embryo, such as preimplantation embryo,[10]  have also raised objections within the pro-life movement.

In short, there appears to be no clear agreement on a precise definition for the term pre-embryo.

So, the question arises: can the term pre-embryo be used non-prejudicially within the abortion debate?

Since it was first coined in 1979 by Clifford Grobstein, the term pre-embryo has unfortunately been used in various ways and at various times seemingly to fit the writer’s agenda, be it political or scientific.

There can be no doubt that the term pre-embryo can be used by pro-abortion or pro-embryo/fetal experimentation advocates.

Precise terminology is crucial for communication in the sciences.  As such, pre-embryo can be a valuable descriptive term to refer to that period of time from fertilization to the development of the primitive streak which indicates one individual person.  Prior to the development of the primitive streak the pre-embryo can split into multiple individual persons.

Biologic development as a factor for moral status is a subject unto itself, but goes back at least to Aristotle and was used in the Christian era by Aquinas, Augustine, and others.  Even today is a critical consideration by moral theologians in assigning moral status.[11]


[1] Donum Vitae: Instruction on Respect for Human Life in its Origin and on the Dignity of Procreation. Congregation for the Doctrine of the Faith, 1987.

[2] Modesto, F.C. The Pre-embryo’s Short Lifetime: The History of a Word.  Cuadernos de bioetica, 23, 2012/3.

[3] Grobstein, C. 1995. Human Development from Fertilization to Birth. In Encyclopedia of Bioethics. R.W. Thomas, ed. New York: McMillan. Vol 2, Fetus I: 847-851.

[4] Ibid.

[5] Jones, H.W.  And Just What is a Pre-embryo?  Fertility and Sterility, 52:2, 1989.

[6] Report and Recommendations of the National Bioethics Advisory Commission. Rockville, MD: GPO, 1997, Appendix-2.

[7] Dox, Ida G. et al. The Harper Collins Illustrated Medical Dictionary. New York: Harper Perennial, 1993, p. 146.

[8] NIH Human Embryo Research Panel — Panel Transcript, February 2, 1994, p. 31.

[9] Kischer, C. Ward. The Big Lie in Human Embryology:  The Case of the Preembryo.  The Linacre Quarterly 64: 4.

[10]  National Institutes of Health (NIH), Transcripts of the Human Embryo Research Panel, 1994, September 27 session, p. 2-7.

[11] Ford NF: When Did I Begin? Cambridge, University Press, 1988.

Previous article
Next articleThe Singing Martyrs of Nagasaki
Alexander J. Lozano is a physician who also holds a Master’s Degree in Theology with coursework at Notre Dame and Boston Colloge. His main area of interest is in Bioethics. He has chaired and served on various Hospital Ethics Committees over the past nearly 30 years and has several published articles dealing with Medical Bioethics.