The ability to retrieve and culture stem cells offers great promise for countless persons who suffer painful, debilitating illnesses.  At the same time, such retrieval raises serious moral and ethical concerns and is thus a matter of great controversy.  To fully comprehend the debate and formulate a position, it is necessary to understand what stem cells are, how they are retrieved, and what benefits they provide.  After a brief description of these facts, I will then proceed to articulate some of the halachic principles that can guide our approach to this sensitive issue.

What Are Stem Cells?

Every cell in the human body contains the entire genetic code of the total organism.  A skin cell contains the DNA of brain, kidney, heart, and liver.  A heart cell contains the DNA of skin, lung, etc.  In the course of embryonic development, in a process
that scientists still do not fully understand and one that gives vivid testimony to the wonders of G-d's creation, various parts of the DNA are switched on or off so that some cells become skin (so the DNA of heart, liver, kidney turns off); other cells become heart (so the DNA of skin, liver kidney turns off).  At the very earliest stages following fertilization (approximately 14 days), the cells have not yet differentiated to acquire specific identities and thus are theoretically capable of becoming any one of the 200+ tissue types that exist in the human body.

Several years ago, researchers at Johns Hopkins University discovered that these early undifferentiated cells could be removed from embryos that were fertilized through the in-vitro process; be cultured indefinitely; and could be "coaxed" through various electrical and chemical processes to become differentiated cells - heart tissue, lung, spinal chord tissue and the like.

It was immediately realized that through the culturing of stem cell lines, one could obtain brain tissue to help persons with dementia, spinal chord tissue to treat paralysis, heart tissue to repair valves, skin for grafts.  Eventually, it might even be possible to reconstruct whole organ systems - to create a heart or a liver - which would alleviate the tremendous shortage of organ donors and avoid the many ethical problems engendered by that process.  It is true that many of claims made for stem cells were grossly exaggerated (a commercial showing Christopher Reeve able to walk if John Kerry would be elected president was a particularly egregious example); nevertheless, although the techniques and technology are still largely in the experimental stage, the promise of major advances is very real.

It is important to note that stem cells can be harvested even from the bone marrow of adults as well as from placentas and umbilical cords but most researchers feel that cells from these sources lack the "plasticity" (ability to be turned into any type of cell) that would make them useful in treatment.  As such, stem cells obtained from embryos offer the greatest chance of therapeutic success.



The Problem

In order to retrieve embryonic stem ells, there must first be a human embryo.  Typically, this embryo is created through in-vitro fertilization.  Removing the undifferentiated cells from the embryo, however, destroys it.  Is the destruction of the embryo an abortion?  Is it murder?  Is it ethically (and halachically) proper to "kill" one life even if it is for the purpose of saving another?  (As the Talmud puts it, "who says your blood is any redder than your friends"?).  Obviously, those segments of American society who see nothing wrong with abortions have no problem with stem cell retrieval.  At worst, it is a very early abortion.  However, those of us who do believe in the sanctity of life at all levels must squarely address the dilemma:  if one disallows stem cell research and retrieval, potentially thousands of people will suffer and die.  On the other hand, if one allows it, is that not equivalent to killing one to save others?  Certainly even good and noble ends cannot justify the means.

[As an aside, in the American political arena, the issue is not whether stem cells research should be permitted or outlawed.  It clearly is permitted.  The issue is only to what degree the federal and state governments should fund and support the research.  As Jews, however, we must consider the very permissibility of the procedure.]

The Perspective of Judaism

(1) Because man is created in the image of G-d and is blessed with intellect and creativity, he/she has a moral responsibility to use that wisdom and creativity for the betterment of the world and the alleviation of pain and suffering.  One is not allowed to refrain from treating the sick on the grounds that G-d in charge and will take care of the problem.  As Maimonides writes in his commentary to the Mishna, he who fails to seek medical attention in the belief that G-d will heal him is as foolish as a person who refuses to eat in the belief that G-d will fee him.  To the degree that stem cell research is halachically permissible; it would become halahically-virtuous and perhaps mandatory..

(2) Abortion - the destruction of fetal or embryonic life - is indeed a very serious prohibition that can generally be permitted only if the mother's life is in danger.  However, abortion is not equivalent in severity to actual murder.  One who destroys a fetus is not liable for capital punishment.  The sin of abortion lies not in the taking of an actual life but in the prevention of a potential from being actualized.
(3) Some poskim permit termination of pregnancy within 40 days of conception based on the Talmud statement that before 40 days, the fetus/embryo is "nothing more than water."  The embryos from which stem cells are obtained are much younger than 40 days; indeed they are less than two weeks old.  However, many eminent authorities, e.g., Rabbi Moshe Feinstein, do not agree to the 40 day rule and would prohibit abortions even prior to that time.
(4)        One possible argument that could be made is that of pikuach nefesh-any abortion is permitted to save the life of the mother. If stem cell retrieval could save future lives, perhaps that factor alone would justify embryonic destruction. On balance, however, this reasoning appears insufficient. First, at this stage  stem cells would be used in research that  would yield knowledge that may save lives in the future. Unless retrieval of the cells would directly result in a lifesaving therapy, the obtaining of knowledge per se does not qualify as pikuach nefesh to set aside activity that would otherwise be prohibited. For example, no one would permit a physician to drive to a lecture on Shabbos because he may learn information that may save a life in the future. Second, even if the  stem cells are retrieved directly for therapeutic use, not all conditions ,as tragic and debilitating as they may be, qualify as life threatening. Dementia and paralysis, for  example, may not justify the violation of the abortion prohibitions. Finally ,it should be noted that according to the Rambam and Shulchan Aruch ,the only reason a fetus can be aborted to save the mother is because the fetus is the source of the mother's endangerment (albeit without malevolent intent) and hence qualifies as a rodef ("pursuer") who may be killed in self-defense. Where the fetus or embryo is not the source of the threat but its destruction could save someone suffering from an unrelated life-threatening condition, abortion would not be allowed even to save the life of another. Stem cell retrieval appears to fall exactly into this category.

(5) Notwithstanding the above, there is a solid basis that would permit stem cell   retrieval even though human embryos are destroyed in the process. Since a fetus or embryo is only a potential not an actual life, some poskim have ruled that the abortion restrictions apply only to a fetus or embryo that is already in the environment where in the normal course of events it will come to fruition, i.e., an embryo that has already been transferred to a womb.  An embryo that is outside the womb has no potential at that point and in that state to ever develop into a life and as such, its destruction is not a prohibited act. (As an aside, this is exactly the position taken by Senator Oren Hatch of Utah who is an opponent of abortion rights but has nonetheless supported stem cell research.)

(6)   This argument is especially strong when we consider the fact that the alternative to stem cell retrieval will not be implantation, pregnancy and birth but destruction for no purpose at all.  These embryos are typically left over from fertility treatments and the parties do not desire to use them.  As such, the choices are: (1) pursue useless destruction through thawing, etc.; or (2) destruction in the process of retrieval of potentially life threatening cells.  Given the reality of that situation, it is difficult to perceive why the second option should be ethically and halachically problematical if the first one is not.

(7) Although halacha might permit stem cell retrieval from embryos that were originally created for fertility purposes that the parties now want to discard ("spare embryos"), it is arguably forbidden to deliberately create an embryo for the purpose of its destruction ("research embryos").  Creating embryos solely for research and destruction might involve the prohibition of emitting sperm for a non-procedure purpose (hotzaat zera l'vatala) and certainly represents a blatant denigration of the sanctity and mystery of human life, reducing it to nothing more than a biochemical commodity that can be manufactured to obtain useful products.  Such a denignation of human life and dignity is ultimately a denigration of the Creator.

(8) It should be noted that it should be theoretically possible to directly create stem cells for any cell in the body, eliminating the need to create and destroy a human embryo.  While such a development is in the long-term future, when it can be done it would greatly minimize these ethical problems.

(9) In any event, even at the present time, efforts should be continued to minimize the destruction of human embryos by continuing to research the use of adult and umbilical cord stem cells.