Kennedy Institute of Ethics Journal

Madam:

In its interesting Report on Human Cloning through Embryo Splitting: An Amber Light (KIEJ, September 1994), NABER (the National Advisory Board on Ethics in Reproduction) discusses ten potential clinical uses of embryo splitting. With one member dissenting, NABER finds two of the uses to be acceptable in principle: (1) “to improve the chances of initiating pregnancy in those individuals undergoing IVF who produce only a limited number of embryos for transfer and implantation” (p. 267) and (2) “to minimize the number of egg retrieval procedures for those undergoing IVF by providing embryos for cryopreservation and future transfer” (p. 268).

However, some members of NABER limit their support for these uses to cases in which none of the embryos into which the originals are split are intentionally destroyed (see pp. 266–68). I find their position puzzling. They consider it “ethically unacceptable to discard cryopreserved embryos” (p. 268). In general, they object to intentional destruction of embryos resulting from embryo splitting. Yet they accept intentional destruction of the original embryos.

Does the splitting of an embryo truly destroy it? Yes, it does, at least if the embryo is split into two equal parts—or into more than two parts, none of which contains a majority of the cells contained by the original. Suppose, for instance, that a two-cell embryo has been split into two one-cell embryos. Then the original embryo, although it may not have “died” and although its cells have both survived, has nonetheless ceased to exist. Even though the resulting one-cell embryos are identical genetically to the original embryo, neither of them is that embryo. (There is nothing to confer this honor on one of them rather than the other.) The original embryo has undergone what I will call “destructive splitting.”

Now it is possible, even likely, that some splittings are not destructive splittings. Suppose that a four-cell embryo is spilt into a three-cell embryo and a one-cell embryo. At least from my perspective as an identity theorist, there is nothing to stop us from identifying the three-cell embryo with the four-cell original: we could say that the original embryo, although diminished, still exists. In any case, there is no indication that any members of NABER intended to limit their acceptance of embryo splitting to cases in which the original embryo survives.

How are we to understand the apparent indifference of conservative members of NABER to the embryo that is split, given their concern for the embryos that result from the split? Perhaps the explanation is found in the following passage:

NABER members represent a broad spectrum of views on the moral status of the embryo, and yet virtually all of them find embryo splitting per se ethically permissible if the resulting embryos are not damaged or destroyed in the process. These members maintain that there is nothing inherently wrong with creating several embryos [End Page 210] from a single embryo, providing all the embryos involved [except the original!] remain intact at the conclusion of the procedure. Embryo splitting parallels the spontaneous production of identical twins or triplets at this stage of embryo development, an occurrence that is accepted in our society with equanimity. The fact that embryo splitting is deliberately used to produce multiple embryos does not make it inherently wrong to employ the procedure.

(Report, pp. 266–67)

This argument appears to rely on the following principle: if something is properly viewed with equanimity when it happens spontaneously, then it is not inherently wrong to bring it about deliberately. At least in its full generality, this is a principle generally and rightly viewed with suspicion (by moral conservatives above all). Although it is proper to view with equanimity, even with relief, the natural deaths of terminally ill patients in great pain, many hold that active euthanasia is inherently wrong.

When NABER has occasion to revisit the issue of embryo splitting, those members who object to destruction of embryos resulting from embryo splitting should make clear whether they accept the destructive splitting of embryos. If they do, they should clarify their reasons for accepting it.