‘Designer Babies’ and Harm to Supernumerary Embryos

Mark WalkerDepartment of Philosophy

New Mexico State University

‘Preimplantation genetic diagnosis’ (PGD) refers to procedures used to test embryos in vitro.

Examination typically involves removal of one or two cells with a needle when the embryo is at the

six- to ten-cell stage of development. Methods of assay, such as polymerase chain reaction and

fluorescent in-situ hybridization, are used to detect genetic abnormalities associated with

monogenetic diseases like Huntington’s and chromosomal abnormalities such as Robertsonian

translocations (Lissens and Sermon 1997; Ogilvie, Braude and Scriven 2005). PGD can be used for

positive selection of traits rather than simply negative selection—avoiding implanting embryos with

serious genetic diseases or disabilities. By ‘selection for positive traits’ we shall mean simply non-

negative selection of traits, that is, traits that are deemed desirable independently of any aim to

avoid implanting embryos with genes associated with serious disease or disability. Some examples

of selecting for positive traits include plumping for genes associated with the potential for increased

muscle mass, perfect pitch, or high IQ. Admittedly, making the distinction in this manner is not

particularly helpful in deciding where to draw the line between negative and positive selection,

since it only puts more pressure on deciding what counts as a serious disease or disability (Glover

2006). However, as will become apparent, such line drawing is not important for present purposes.

Much of the possibility of selecting positive traits remains prospective: we do not have the

knowledge at present to select for genes associated with traits like intelligence and perfect pitch.

However, current rates of advancement suggest that there is a significant possibility of testing for

an increasing number of positive traits in the near-term (i.e., in less than twenty years (Stock

2002)). And not all uses of positive selection remain prospective, for it has been used in at least a

couple of different types of cases. One is with so-called “saviour siblings”: selecting an embryo

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because it is a potential tissue donor for an ill elder sibling (Sheldon and Wilkinson, 2004a). A

second area of positive selection happens when PGD is used for sex selection (Savulescu and Dahl,

2000; Ray et al., 2002).1

The selection of embryos for positive traits is sometimes referred to as the creation of ‘designer

babies’. We will use the rhetorically more neutral ‘PPGD’ to refer to the entire process of using

PGD for selection of positive traits. This process includes (a) the creation in laboratories of

supernumerary embryos2, (b) PGD as the method of genetic assay3, (c) screening for positive traits,

and (d) the implantation of the selected embryo(s).

The fact that there is already a limited use of PPGD, combined with the expanding list of

positive traits that might be tested for, is generally recognized as inviting discussion of its moral

and policy implications (Steinbock 2002; Robertson 2003; Ogilvie, Braude and Scriven 2005). One

way to parse the moral concerns is in terms of how PPGD might affect the embryos created during

PPGD, and how PPGD might affect others. Among the latter are concerns about social justice

issues, e.g., ‘What if only the rich can afford PPGD?’ There are also questions concerning the

extent to which parents should enjoy reproductive liberty: ‘Would prohibiting PPGD infringe on the

rights of persons to reproductive autonomy?’ And the different purposes for which PPGD might be

deployed raises more specific questions with respect to each purpose, e.g., ‘Does creating a saviour

sibling mean that we are treating the saviour sibling as a “mere means”?’, and ‘Will permitting sex

selection lead to an imbalance of sex ratios?’ In the case of selecting for genes like intelligence,

issues sometimes discussed under the umbrella of ‘eugenics’ are raised, e.g., the question of 1 We need not assume that all sex selection is an instance of positive selection: there are sex-linked diseases that may provide a reason that underwrites the claim that, for some couples, sex selection is “negative” selection. 2 It is possible that PPGD could be used in certain cases and no embryos go unimplanted. Imagine a single embryo is created, and the use of PGD reveals that it just happens to have the desired characteristics. Subsequent discussion should make apparent why we are justified in ignoring this possibility. 3 The discussion focuses on PGD here simply because it is the technology of choice at the moment for the selection of positive traits. This may change. For example, presently, embryos are routinely screened through microscopic examination for gross signs of abnormality associated with genetic disease. An anonymous referee points out that advances in imagining techniques could conceivably make positive selection possible. The argument here could be straightforwardly applied to this or other technological developments for screening for positive traits.

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whether non-designer babies might be harmed because they could potentially be seen as genetically

inferior. Our focus here is with the former question, that is, the effects of PPGD on the embryos

created during this process, specifically, the harms that might come to embryos created through a

policy that permits PPGD. Since PGD is considered reasonably safe (Ogilvie, Braude and Scriven

2005), we will assume that there is little concern that PGD as a method of assay harms implanted

embryos.4 One important moral concern is the effect on the embryos that are not implanted. The

question has been raised in the popular press with respect to the use of PPGD to search for saviour

siblings: "What happens to the embryos not lucky enough to be chosen as a tissue match?"5 Since,

as noted, we shall assume, a policy of PPGD inevitably means that some embryos will be not be

gestated, the connection with the abortion debate, as a number of authors have noted, seems

obvious. For instance, Steinbock (2002) says that it seems a fair assumption that liberals on the

abortion issue, that is, those who believe that even later term abortion is permissible, should not

ethically object to PGD in terms of any harm to the embryo. This is because (typically) liberals

assign less than full moral status to the foetus.6 On the other hand, there are

conservatives on abortion who claim that even a fertilized egg is a human person

with all the rights of any other human person (John Paul II 1993). For them …PGD

is not ethically preferable to abortion, as both are forms of homicide, indeed, murder.

In fact, from the perspective of the loss of prenatal life, PGD is worse than

4 But see Bellieni and Buonocore (2006) for recent evidence to the contrary. There is also controversy whether PGD might actually increase the mortality rate of embryos during gestation (Mastenbroek, et al. 2007). (It should be noted that the results of this study have been hotly contested in subsequent issues of the New England Journal of Medicine and elsewhere). It will be argued below that PPGD does not harm embryos even if the Mastenbroek et al. study is correct. A different sort of worry is expressed by Habermas (2004) who argues that individuals created through this process will grow up with a truncated sense of personal autonomy. We will pass over such objections, although the argument here is perhaps relevant: arguably it is better to grow up with less autonomy than to not exist.5 Hudson F. Parents’ plea on baby plan. Herald Sun 2002 Apr 17: news section: 7. Quoted in Spriggs and Savulescu (2001).6 This need not be the case. Thompson (1971) famously argued that, even on the assumption that a foetus is a person, a liberal position can still be maintained.

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traditional prenatal diagnosis and abortion, because PGD requires the creation of

numerous embryos for each live birth produced. (Steinbock 2002:176).7

So, while the issue of the moral status of the embryo may not be decisive8, it does seem a key

ingredient in the assessment of the permissibility of permitting PPGD, at least to this extent: if we

believe with conservatives that embryos (because they are persons) can be morally harmed (John

Paul II 1993; George and Gomez-Lobo 2005) then a policy permitting PPGD harms embryos.

Conversely, if we believe with (some) liberals that embryos cannot be morally harmed (because

they are not persons) then a policy of permitting PPGD does not harm embryos.9 It will be argued

that it is a mistake to think that there is a parallel here. Specifically, the point to be made is that on

either understanding embryos cannot be harmed by a policy that permits PPGD. This is a common

thought, given the liberal view. For example, some liberals (e.g., Sumner, 1981) argue that only

sentient beings can be morally harmed, and embryos are not sentient, so they cannot be morally

harmed.10 The real argumentative burden of this paper is to show that even if we assume with

conservatives that a fertilized ovum is a person, a policy that permits PPGD does not harm the

embryos.

Let us begin by working through an example. Suppose in the not too distant future PPGD is

permitted as a matter of policy. A couple walks into their local reproduction clinic in the hopes of

having a certain sort of child. On a clipboard they check off a number of boxes indicating that they

7 As an anonymous referee points out, typically fertility clinicians will attempt fertilization of all oocytes recovered, so it is not clear that more embryos are created when PGD is performed than if not. The upshot is that the conservative’s protest might be better understood as directed against the practice of creating supernumerary embryos rather than PGD. 8 Again, Thompson (1971) is relevant here.9 This should be qualified by saying “cannot be morally harmed qua persons”. See the next note. 10 Obviously this is not the only means to establish that embryos do not have full moral status. For example, there is argument over whether embryos are ontologically different from the later stage foetus because embryos can “twin” (Smith and Brogaard, 2003; Damschen, Gómez-Lobo and Schönecker 2006, Guenin, 2006). Clearly more needs to be said about the inference from the claim that embryos are not persons to the conclusion that embryos cannot be harmed. For example, a liberal might think that dogs and cats can be harmed even though they are not persons. We could add the claim that embryos are not capable of feeling pain, but even this may not be sufficient for claiming that embryos cannot be harmed. Liberals might invoke perfectionism (Hurka, 1994) to argue that organic life in general can be harmed. To my mind, these are important and interesting questions, but they are not particularly germane to our discussion, since we will be granting the assumption that embryos are persons.

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are hoping to implant an embryo with genes associated with the potential for high intelligence,

perfect pitch, increased muscle mass, and a happy disposition. They supply the spermatozoa and

ova from which 4 embryos are created in a lab. A variety of tests are conducted and a single

embryo that best meets the couple’s specification is selected for implantation. The others are

destroyed. In order to remind ourselves that we are assuming that the embryos are more than just a

few cells with less than full moral status, we shall name our four embryos: Abby, Bill, Carl and

Diane (ABCD). The conservative objection to this policy is that it permits a great harm: the death

of three persons. The reasoning here may seem unassailable. Let us suppose that it is Abby that is

selected for implantation, while the other three suffer a premature death. Premature death is

(typically) considered to be a great moral harm; indeed, one of the greatest harms that an individual

might suffer. So, it seems, Bill, Carl and Diane are harmed by a policy that permits PPGD. For

conservatives, killing Bill, Carl and Diane is morally analogous to parents killing adult offspring: it

is murder in either case. Permitting parents to kill their adult children morally harms those children,

so by the same token, PPGD is morally harmful to Bill, Carl and Diane.

The basic problem confronting the conservatives’ reasoning is that it ignores Parfit’s non-

identity problem (Parfit 1976 and 1984). The argument applied to the present concern may be stated

briefly as follows: a policy that permits PPGD does not harm the embryos created as a result of this

policy because the alternative for the embryos is to never have been born. For individuals like

Abby, Bill, Carl and Diane, the policy that permits PPGD is their “portal to the world”, and

provides them with some chance at a long worthwhile life. Having some chance at a long

worthwhile life is, other things being equal, better than not being born. PPGD provides them with

just this chance. So, whatever moral reasons there might be against PPGD, it cannot be that PPGD

harms persons created in this fashion because a chance at a long and valuable life does not harm—

indeed—is of benefit to those created in this manner.

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The argument may be laid out schematically as follows:

P1: Either policy permits the use of PPGD or it does not.

P2: If we do not permit PPGD then the chances of ABCD existing are virtually nil.

P3: If the chance of ABCD existing is virtually nil then there is virtually no chance at a

worthwhile future life for ABCD.

P4: So, if we do not permit PPGD then there is virtually no chance for a worthwhile future life

for ABCD.

P5: If we implement a policy that permits PPGD then there is some chance for ABCD to have a

worthwhile future life.

P6: If the only alternative is having virtually no chance at a worthwhile future life, then being

provided with some (even small) chance at a worthwhile future life is not harmful.

C: So, a policy that permits PPGD does not harm ABCD.

What follows is an explication and defence of this argument.

Premise 1 is relatively uncontroversial. In broadest terms, the policy options are to either

permit PPGD or not. To not permit it, we shall assume, is to make PPGD illegal.11

The support for P2 relies on the assumption that a necessary condition for being a particular

individual is that a particular spermatozoon and ovum have united. For example, if the

spermatozoon that united with the ovum that created Abby had in fact fertilized a different ovum,

for example the ovum that was used in the creation of Diane, then neither Abby nor Diane would

exist. Some other individual, call this individual ‘Natalie’, would have been created. The chances

that the particular spermatozoon and ovum that make up Abby uniting in some other way, e.g.,

11 We shall ignore what some might take to be an alternative to merely permitting PPGD, namely, a policy of obligatory use of PPGD. I ignore this option since no serious commentator on these issues, to the best of my knowledge, is advocating that the law, for example, should require PPGD. And if PPGD were obligatory the same reasoning offered here could be applied to show that embryos are not harmed by an obligatory policy of PPGD, although the individuals created would in all likelihood be different from those created where PPGD is merely permissible.

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during old-fashion coitus, is astronomically small. For in vitro fertilization (a necessary component

of PGD) requires fertilization to occur in a lab. The prospective father provides literally millions of

spermatozoa—a count of less than 20 million spermatozoa per ml of semen is considered low.

Furthermore, the natural course of female ovulation is often altered for IVF, and typically requires

that women be injected with buserelin and gonadotrophins to regulate and increase ova production.

So, if PPGD were not an option for these parents, there is some chance that ABCD would not exist

simply because the couple may choose not to conceive where positive selection is not possible, or

because the couple is unable to conceive through coitus. But even if the couple is able and willing

to procreate by coitus because PPGD is not available, the chances of any of ABCD being created

through coitus are so astronomically small that they are not worthy of consideration. So, if ABCD

had not been created during PPGD, then for all intents and purposes, they would never have

existed.12

Premise 3 simply asserts what we may take to be an uncontroversial claim: existence is a

necessary condition for having a worthwhile life. The thought experiment to confirm this is pretty

simple: try having a worthwhile life without existing. Notice that this differs from two more

controversial claims. One is the claim that merely being born is a benefit. Certainly, if existence is a

benefit then PPGD provides ABCD with a benefit. Yet the argument does not require us to make

this assumption. Moreover, if we agree with those that say that it does not make sense to say

existence is a benefit, then this does not amount to the denial that existence is necessary for a

worthwhile life. The other claim is that existing is sufficient for having a worthwhile life. Not

everyone agrees that every life is worthwhile, e.g., lives with unremitting pain with no achievement

and happiness are considered by some to be not worthwhile (Parfit, 1984; Glover 2006). The claim

that existence is necessary for a worthwhile life is neutral on the sufficiency issue.

12 For further argument about the contingency of one’s existence see Parfit (1984), Kavka (1982) and Woodward (1986).

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Premise 4 follows as a logical consequence of P2 and P3 (On the assumption of transitivity of

conditionals).

P5 is purposely somewhat vague. As the probability of being implanted approaches 0 then the

argument is less persuasive. For example, if (per impossible) one could create billions of embryos

from a single set of parents, the chances of being selected for implantation here might approach that

of the chances of being conceived naturally, and so in this case the premise might have to be

rejected. Similarly, if the chances of being implanted approach 1.0, e.g., if only one in a billion

embryos is not selected, then at least some conservatives might accept this, given that these are

much better odds than natural reproduction offers. In any event, to avoid the argument being

criticized as trivial because the odds are too high, we shall work with .25 odds. The argument might

work well for odds as low even as .001. This would imply the possibility of using PPGD to select

one embryo out of 1000. It is not likely that this many embryos would be created for the purposes

of PPGD given the relative difficulty in procuring ova.13

P6 might be thought to be the most controversial premise, but the claim it makes is actually one

most of us are probably willing to accept, as the following analogy suggests. Imagine you are flying

on a small airplane with four others. As is the way with philosophy examples, the airplane has

suffered a catastrophic accident. Anyone who remains on board will certainly die. As luck would

have it, there are four parachutes, three of which are known to be damaged and one in good repair.

You (selflessly) randomly assign the parachutes to the other four not knowing which one is in

working order. It seems that you have not harmed your fellow passengers even though three of the

four are sure to die. Now suppose it is objected that this “policy” of passing out the parachutes is

tantamount to murder for three of the four parachutists, since three of the four are sure to die. This

13 I won’t explore this here, but this line of reasoning might be used to support the idea that embryos purposely created for stem cell research does not harm embryos so long as there is at least a small chance that any given embryo might be implanted. For example, a lottery might be held with a 1/10,000 chance of implantation, or more realistically, that policy required that embryos created for stem cell research being available for adoption. Each embryo created for research, then, may have some small but real chance at a worthwhile future life.

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may strike us as nonsensical, since the alternative is to have no future. The protest of murder in the

parachute case is analogous in some respects to the conservative’s protest regarding the policy

permitting the destruction of embryos.

One assumption we will make here is that both the successful parachutist and the implanted

embryo will have (an excellent chance at) a worthwhile future. Obviously this need not be so in

either case. Imagine the plane is flying over enemy territory and landing successfully would mean

certain capture, torture and death. In this case we can see some reason for protesting being given the

parachute option. However, we have avoided this by stipulating that the individual handed the

working parachute will have a worthwhile future life. Similarly, if we were of the opinion that if we

were to implant certain embryos whose future prospects looked so dim, e.g., we foresee a short

painful life with little or no cognitive or social development say, we might reach the verdict that

implanting would not benefit such individuals. Again, let us simply stipulate that any sort of

negative selection of this sort has already taken place, and that any embryos implanted would have

a worthwhile life, that is, a life that is a benefit to them. So for each of ABCD, we shall suppose

that they would have a life that would be well above any such minimal threshold, and that they

would benefit from being implanted.14

One difference here between the PPGD case and the airplane case that is not particularly

relevant for our purposes is the traumatic experience of the parachutists. Since the embryos

experience nothing they will not have to fear their own death in the way that the parachutists will,

so we can ignore this complication. Of course it is unrealistic to think that this would not be

terrifying, but let us assume that death by parachute failure is equally traumatic as death by plane

crash. That is, there is no reason to prefer the terror of one to the terror of the other.

14 Again, I take no position on where to draw the line on lives worth living. Glover (2006) cautions us against assuming that it will necessarily be one that is free of disease and disabilities. We can assume that whatever base line is established, if there are any embryos that do not meet this “minimal standard” then they have been eliminated from candidacy for implantation.

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It seems, then, that the general underlying principle is sound: other things being equal, some

chance at a worthwhile future life is better than no chance at a worthwhile future life. Thus, it

would make no sense for one of the parachutists to object that she is being harmed because she only

has a .25 probability of landing safely, and so too it does not make sense to protest on behalf of

ABCD that they only have a .25 probability of being implanted.

It might be remonstrated that this is to misstate the chances for the four individuals. Assume

that the parents have very stringent criteria for the sort of genome they are looking for in their

offspring such that only Abby best fits these criteria. This means, barring mistakes and accidents,

Abby is almost certainly going to benefit from PPGD while the other three are almost certainly not

going to benefit. The objection confuses metaphysical and epistemic possibilities (Kripke 1980,

Lewis 1994). Prior to genetic diagnosis, for all we know, each of the four individuals has an equal

chance of being implanted, just as in the parachuting example. Which parachute is functional is not

determined by a stochastic process, rather, only one parachute is in working order. If Sara is one of

those handed a parachute, then the epistemic possibility of the parachute working is .25. Of course

it is true that the metaphysical possibility of the parachute working is either 1 or 0: either Sara was

handed the good parachute or a dud. The parallel argument here is that only one individual benefits

from using a parachute while the other three do not. Despite this, it makes perfect sense to say,

given that we do not know which one is working in advance, all four will benefit from being

provided with the .25 chance of obtaining the working parachute. Similarly, prior to genetic testing,

all four embryos are in exactly the same position: as far as we know, they all have an equal chance

of being implanted, so PPGD is an overall benefit to each embryo.

It might be objected that the argument cannot be correct because it leads to the absurd result

that Bill, Carl and Diane are not harmed when they are killed. However, since we have agreed that

if they were implanted their lives would be worthwhile, Bill, Carl and Diane are harmed by the

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denial of an opportunity for a future. This criticism is apt, at least to this extent: it invites

clarification as to how we should understand the notion of ‘harm’. For example, we might ask

whether a dentist harms her patient, and be tempted to say “yes and no”. Yes, to the extent that the

dentist causes some pain; no to the extent that the dentist is able to promote better health and less

future pain. We might say that overall the dentist does not harm the patient, and overall the dentist

benefits the patient.15 The argument above uses ‘harm’ in the latter sense, that is, in terms of an

overall assessment of the harm or benefit. By the expression ‘overall benefit or harm’ we mean to

indicate that many acts or policies might provide some mixture of harm and benefit to the

individuals affected. An assessment of the overall benefit or harm requires weighing harms and

benefits in order to assess whether individuals are better off all considered, or worse off all

considered. If they are better off all considered, then we say that they benefit overall. If they are

worse off, then we say that they are harmed overall. Thus, if I present you with a gift of a million

dollars in the form of a cheque, and you get a small paper cut while snatching the cheque, we might

say that this act, presenting you with a cheque, leads to both a benefit and a harm. The benefit, of

course, is a positive change in your financial situation; the harm is the paper cut. Most of us would

agree that this is an overall benefit to you: the harm experienced is outweighed by the benefit.

Conversely, if I present you with a gift of a ten dollar cheque, and you receive a paper cut that

becomes infected and leads to the amputation of your hand, this is an overall harm. True, you

received some benefit, ten dollars, but this is outweighed by the harm of amputation. A physician

might routinely operate on patients under the following conditions: if successful, the surgery

enables patients to fully recover and live a long and worthwhile life. But there is only a .25 chance

of success and a .75 chance of death. If 99% of patients die from the disease in short order without

treatment, we might say that the opportunity to receive surgery is a benefit to them, even if they die 15 Thus our use of ‘harm’ here differs from, for example, Harman (2004) who uses it in the sense that makes it perfectly acceptable to say that the dentist harms her patient, even though the treatment is necessary for the benefit of future health.

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as a result of the surgery. If we accept that a policy permitting PPGD may harm embryos, still we

can argue that it is an overall benefit for the embryos. For if policy prohibited PPGD then the

embryos would never have existed. Conversely, with a policy that permits PPGD, it is foreseeable

that three of the four will be killed; still, the harm of this chance of being killed is outweighed by

the benefit of a chance to be implanted. So, the assessment must be that embryos benefit overall by

the chance to be implanted even though most might be destroyed. The same point can be made with

reference to the airplane analogy. Imagine Sara's “disappointment”—to radically understate her

probable reaction—when she realizes that her parachute is one of the duds. Of course it would be

silly to protest that you harmed her when you gave her the parachute, since it was known that there

was a good chance that she would be “disappointed” and then die. Overall, it was not harmful to

provide Sara with a parachute, since it gave her at least a chance of surviving. The alternative, as

we have said, is certain death.

It is important to point out a claim that is not being made with the use of this analogy,

namely; that ABCD would be harmed if they were never created. No such claim is made here, even

though the parachute analogy might suggest such a claim, e.g., we can imagine the protest that if

the four passengers were not provided with the opportunity for some chance at a successful descent

they would be harmed, and so analogously, embryos might be harmed if they are not given some

chance at implantation by permitting PPGD. The difference of course is that in the parachute case

we are to imagine actual people; whereas, if PPGD is banned, then ABCD are merely “possible

persons”, and we shall assume that mere possible persons cannot be harmed (Parfit, 1984; Heyd,

1992). So the argument does not require us to say that ABCD would be harmed if PPGD were

banned. All that is required for the argument is the claim that ABCD are not harmed by permitting

PPGD. If one believes that possible persons can be harmed then not permitting PPGD is an

additional reason for not protesting PPGD on ABCD’s behalf.

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It is worth noting too that the argument may not commit us to saying that PPGD does not

wrong ABCD. To see this, consider a well-known example from James Woodward (1986): suppose

David, a person of African-American descent, is denied a seat by an airline ticket agent on a plane

for reasons of racial segregation. The plane subsequently crashes and all on board die. Let us grant

that David has been wronged because his equality rights have been denied by the airline

representative. Has David been harmed by this action? In one sense yes: racial discrimination is a

terrible affront to one's dignity. Yet, in our sense, it seems that David has not been harmed overall,

because he escaped the plane wreck. Surviving is of greater benefit to him than the harm caused by

discrimination. If we accept this line of argument, then we might say that BCD are not harmed,

even if they are wronged by having their rights violated. Whether we should accept this line of

reasoning is a large question that we will not pursue here. Rather, we will have to be content with

the more modest conclusion that the inference from 'BCD are not harmed by the PPGD process' to

the conclusion 'their rights are (or are not) violated' is one which this argument need not take a

position on.

We are now in a position to draw the conclusion of our argument. Given that a policy that

prohibiting PPGD means that ABCD will have virtually no chance at a worthwhile future life, and

that PPGD provides them with some chance at a worthwhile life, and given the general principle

that giving some chance at a worthwhile life does not harm, when the alternative is to have almost

no chance, we can conclude that a policy that permits PPGD does not harm embryos.16

The conservative position, as we have outlined it, says that a policy of PPGD harms embryos,

and so a conclusion that says that PPGD does not harm embryos is sufficient to refute this. While it

is not strictly necessary for our argument, we are in a position to draw an even stronger conclusion:

16 As noted above (noted 4), there is some concern that PGD kills some embryos: the removal of blastomeres kills some embryos, and Mastenbroek, et al. 2007 suggests that the survival rate of embryos assayed by PGD might be lower than those not tested. Even if the attrition rate with PGD is quite high our example will still work. Suppose that the losses from assay and lower implantation rates amount to 50%. We can adjust the example to suppose that eight embryos are created, each with a 12.5% chance of successful implantation.

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PPGD is a benefit to the embryos. For even if being born is not a benefit, PPGD provides a benefit

for the four individuals: it provides them with an opportunity for a chance to be implanted and have

a worthwhile future. Most will grant that having a worthwhile future is of great value to the

individual. The point can be underscored by thinking about the plane example: being provided a

parachute, even if it has low odds of working, can be seen as a benefit given the alternative. This

difference between harm and benefit is relevant because some policies are already being formulated

in terms of benefits to embryos, for example: “In Germany, only procedures of direct benefit to the

embryo are allowed, and PGD is therefore prohibited at any point following pronuclear fusion”

(Ogilvie, Braude and Scriven 2005).17 So long as we think that having some chance at a worthwhile

future is a benefit where the alternative is to have no chance then a policy permitting PPGD does

benefit embryos. Given this line of argument, if countries like Germany want to ban PPGD it must

be for some other reason than PPGD does not provide a benefit to the embryos created through this

process.

The most serious objection has been saved for last. We will consider four versions of the

objection, in increasing order of sophistication. The most basic version of the objection is as

follows:

The argument offers us a false dilemma: it is simply not the case, as the argument assumes,

that either there is no chance at existence; or, a one in four chance at a future for the embryos.

Surely we can imagine better policy options for Abby and her siblings, for example, a policy that

requires all embryos to be implanted. The policy of implanting one out of four is a version of an

“Implant-Some” policy. The Implant-Some policy is perhaps a benefit given the alternative to not

being born, but it is not a benefit in comparison to the “Implant-All” policy.

17 See Robertson (2004) for a review of legislation in Italy with the same intent, and Sheldon and Wilkinson (2004b) for similar concerns in British legislation.

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As is perhaps evident, this form of the objection overlooks the fact that instituting PPGD as

policy is a necessary condition for the existence of ABCD. For suppose that the Implant-All policy

was put in effect rather than PPGD. A difference in policy like this may mean that the two

individuals who would have been the parents of ABCD might never meet. Even assuming that the

couple bonds, the point of genetically testing for positive traits would be lost, since each embryo is

to be implanted in any event. Under these conditions the parents that would have had ABCD under

a policy of PPGD might not have any children, had fewer embryos created, or perhaps have

procreated the old fashion way, etc., but none of these alternatives offers any significant chance for

Abby and her three siblings, because these alternative means to creating offspring will result in

different children. Whatever we might think about an Implant-All policy, it cannot be that this

policy would benefit Abby and her siblings.

In effect, the Implant-All policy is tantamount to denying PPGD, since it does not permit

parental choice with respect to which embryo is chosen. However, we can now imagine dissent

based on the fact that there is no reason to think that PPGD requires the destruction of embryos,

e.g., we can imagine a policy that permits parents to choose embryos while requiring that all

supernumerary embryos be saved through cryogenic preservation for possible adoption and

implantation in the future by others.18 Such a position seems to be a better alternative for ABCD,

for even if Abby is the single embryo chosen by her parents, BCD might bide their time “on ice”

with some chance at future implantation.

To grapple with this objection we should consider three possible freezing-the-not-chosen

policy options:

1. Prohibition on Freezing: Public policy should prohibit cryogenic freezing.

18 I owe this objection to an anonymous referee.

15

2. Permissible Freezing: Public policy should continue the current practise that

permits (but does not obligate) the cryogenic preservation of embryos and the adoption by

other prospective parents.

3. Obligatory Freezing: Public policy should make obligatory the cryogenic

preservation of embryos and their availability for adoption.

Since the assumption in the main argument is that BCD are killed, it might be thought that they

are created in a future where the Prohibition on Freezing policy is in place. However, it is hard to

imagine a future with this policy given how little support it is likely to garner. After all, the practise

of cryogenic freezing of embryos is well entrenched today: there are many facilities devoted to this

end with estimates of approximately 400,000 embryos cryogenically frozen presently in the USA

alone (Hoffman et al., 2003). In addition, a policy that required unimplanted embryos to be

destroyed would hardly find favour amongst conservatives, because they would understand this as a

policy that requires the killing of persons. In general, liberals too would have little reason to support

such a position, in part, because some may protest that it infringes upon parental reproductive

autonomy. Furthermore, embryos are created only with some difficulty, and so it would seem

pointless to insist that parents undergo multiple procedures for obtaining ova and sperm when a

single round with cryogenic preservation would suffice.19

Rejecting the Prohibition on Freezing policy means that we should understand PPGD operating

under the Permissible Freezing policy. Applying this to our example, we should understand the

parents of BCD elect to forgo the freezing option altogether, or opt for cryogenic suspension

initially and then subsequently choose to have BCD destroyed. Accordingly, we should understand

the objection as stating that the Obligatory Freezing policy does less harm to BCD compared with

the Permissible Freezing policy. If this is so, then it seems that conservatives are in a good position

19 As intimated above, the procedure here is inherently much more burdensome for women.

16

to say that there is a policy that is consistent with the existence of ABCD, which does not lead to

the destruction of any of them, thus, the argument is unsound.

The main20 reason for thinking that Obligatory Freezing would not be of benefit to BCD

involves the usual non-identity reasons. Since we are assuming that ABCD are created under the

Permissible Freezing policy, the counterfactual situation where Obligatory Freezing governed

PPGD would be a major policy shift. One reason to think that it is a major shift is based on

evidence concerning current parental embryo adoption decisions. As noted, Permissible Freezing21

is the current policy in many jurisdictions governing the dispensation of supernumerary embryos

created during assisted reproduction. This means that parents must decide whether to dispose of the

embryos, allow the embryos to be used in research, or permit other couples to adopt the embryos.

Presently, most couples choose either to dispose of their embryos or allow them to be used in

research. Only a small percentage of parents choose to allow other couples to adopt. While there is

some range in studies investigating how likely parents are to allow others to adopt their embryos,

studies generally indicate less than 20% of parents are willing to allow adoption.22 That parents

would rather see the embryos destroyed than allow others to potentially benefit through adoption

suggests that this is a matter of some importance to the biological parents. For example,

Hammarberg and Tinney report the following as indicative of the reasoning process of couples who

choose not to donate:

20 A different reason turns on the fact that there have been very few adoptions of embryos, numbering in only the hundreds. A policy of obligatory freezing would increase the chances of any embryo being part of the adoption pool, yet a larger adoption pool would decrease the chance of any embryo being adopted from the pool. 21 This is not quite right, since in most jurisdictions embryos are not recognized as persons and so 'adoption' may not be the correct term here. This wrinkle does not affect our discussion.22 On the high side is the study by Hammarberg and Tinney (2006) where 16% of the couples surveyed agreed to embryo adoption, which as they note, is atypical for similar studies. More typical are the studies by Van Voorhis et al. (1999) that report that 12% were willing to donate embryos, and McMahon et al. (2003) at 10%. Amongst the lowest is the study by Saunders et al. (1995) at 2.9%.

17

It was a very difficult decision which took us over 7 years to make. In the end we

were forced to decide due to my medical condition, however it was something which

caused us a great deal of anxiety and always will (Hammarberg and Tinney 2006).

Another couple responded to their questionnaire as follows:

We thought about the frozen embryos whenever a bill arrived, but being unable to

make a decision, kept paying the bills and keeping the embryos frozen. I would have

loved to donate them to another couple but I couldn't have coped with knowing that

someone out there had my biological child and my husband thought some strapping

18 year old ringing on the doorbell in years to come was a real issue (Hammarberg

and Tinney 2006).

As these quotes indicate, for some parents, allowing their embryos to be adopted is a weighty

option that they choose not to exercise. So, if Obligatory Freezing policy governed PPGD many

parents would have to weigh the importance of using PPGD to select a child against the perceived

negative of having their biological offspring potentially raised by others. It seems plausible that at

least some parents would feel so strong about this that they would choose coitus rather than PPGD

to create a child. Even parents who use PPGD despite this perceived negative may reduce the

number of embryos created, so as to reduce the number of potential biological offspring knocking

at their door 18 years hence. In either case, Obligatory Freezing looks as though it would lead to the

creation of a different set of persons as compared with Permissible Freezing, for it would impact the

manner and timing of reproduction decisions. In which case, Obligatory Freezing may offer the

opportunity for other individuals to exist, but in all likelihood would mean that ABCD are never

created. So, Obligatory Freezing does not offer a less harmful outcome for ABCD than the one

envisioned under Permissible Freezing.

18

The next two variants of the objection add a diachronic dimension. We will initially consider

Implant-All as an alternative to PPGD23, and then consider the diachronic cryogenic possibility. The

diachronic version of the Implant-All objection is as follows:

Think of T1 as a point in time prior to the creation of ABCD and T2 as a point moments after

the creation of ABCD. Let us assume that a policy permitting PPGD at T1 must be in place in order

for ABCD to be brought into existence. However, as soon as ABCD are brought into existence at

least three of ABCD would benefit from a policy reversal, specifically a change from PPGD to

Implant-All. Since the policy reversal happens post-creation, the Parfitian point about the

connection between identity and existence of PPGD no longer holds, that is, the existence of ABCD

is no longer tied to PPGD once ABCD are created.

Given the assumption that PPGD selects from embryos with lives worth living, at least part of

the objection must be conceded: a policy reversal of the sort described would be to the benefit of

Bill, Carl and Diane. The paradox comes as we think about how to assess our policy options at T1.24

Suppose prospective parents say that they will not use PPGD unless they can be assured that PPGD

does not harm any embryos created. Using the main argument of this paper we might say that

PPGD does not harm any embryos created because it allows at least some chance at a worthwhile

life. But we can foresee at T2 that a policy of Implant-All would be to the benefit of any embryos

created. So, if we report back to the would-be parents at T1 that a policy of Implant-All is to the

benefit of the embryos at T2 then we can assume that they will not embark on PPGD knowing that

this policy at T2 will harm the embryos. But then it seems that we should say to the parents at T1

that PPGD does not harm the embryos, for otherwise they will never be born. The paradox arises,

23 Unless explicitly noted otherwise, we shall assume in what follows that PPGD is conducted under the Permissible Freezing policy.24 In [Ref] it is argued that there is a genuine paradox here in thinking about non-identity issues that extends well beyond the present case, for example, this paradox is implicit in Parfit's main illustration of the non-identity issue, namely, his example of “Conservation versus Depletion” (Parfit, 1984). Admittedly, the practical resolution offered here is not theoretically very satisfying.

19

then, because at T1 it seems that we should assert both that PPGD does not and does harm ABCD.

That is, it does not harm them, since it is a necessary condition for their chance at a worthwhile

future; it does harm them once they are born because it is an Implant-Some policy, yet only a policy

of Implant-All means that all of ABCD survive to have a worthwhile future.

The upshot is that for all of ABCD to have a worthwhile life there must be just such a “policy

reversal”. By this it is meant that PPGD is policy at T1 and then at T2 the policy is changed to

Implant-All. The trouble is that in practical terms it is difficult to see how we could plan for such a

policy reversal. For suppose we announced as policy at T1 our intention to reverse policy at T2, a

time shortly after when ABCD would be created. This announcement would mean that the would-

be parents of ABCD will have no reason to undergo the procedures necessary for PPGD, and so

announcing this policy reversal will amount to the same for ABCD as if PPGD were never

permitted. Thus, if it is announced at T1 that the policy will change at T2 then the parents of ABCD

would have little reason to undergo the invasive procedures required for PPGD in order to select a

specific embryo if it means that all of ABCD will be implanted in any case. Perhaps authorities

could propagate the “myth” that PPGD is a long-term policy knowing full well that as soon as

embryos are created the Implant-All policy will be enforced. Keeping secret such a policy reversal

is so impractical that even Plato might blush at its proposal. If we cannot plan for such a policy

reversal then it seems that the only practical alternatives are either to permit PPGD (and not plan to

reverse the policy in the future), or to not permit PPGD. The latter, as we have said, is not a means

to not harming or benefiting ABCD, since then they will never be born.

Similar remarks apply when thinking about the temporal version of Obligatory Freezing. The

thought here, of course, is that at T1 ABCD are created under the Permissible Freezing policy and

then at T2 Obligatory Freezing is instituted. After ABCD are created, there is no doubt that a policy

reversal at T2 to Obligatory Freezing would be of benefit to BCD. True, the chances of BCD being

20

implanted under such a policy are probably quite small.25 Nevertheless, a small chance is better

than no chance, and so a policy reversal is to the benefit of BCD. If, for example, BCD happened to

be born just as there was a change in political leadership, and the policy regulating PPGD was

changed from Permissible Freezing to Obligatory Freezing, then clearly BCD would benefit. This

does not change the fact that there is no practical means at T1 to plan for such a benefit for BCD.

As before, if the policy were announced that Permissible Freezing would be permitted up to T2, at

which time policy would switch to Obligatory Freezing, then the chances of BCD being born are

negligible. Announcing in advance such a policy reversal would no doubt affect the decision-

making of any number of prospective users of PPGD. Some parents might be prompted by the

impending legislative change to use PPGD and have the unselected embryos destroyed before T2;

others might forego or postpone the use of PPGD, not wanting to have to make a decision about the

fate of supernumerary embryos before T2. Obviously if the would-be parents of ABCD are in either

of these groups then such a policy change will not benefit all of ABCD, for either BCD will be

destroyed or the would-be parents of ABCD will delay procreation, and hence, ABCD will never be

born. Even if the parents of ABCD are in neither of these groups—suppose their preference for not

having the embryos adopted is so slight, that the anticipated policy reversal does not affect their

decision to use PPGD—the planned policy reversal may still affect them, e.g., it might mean that

their access to PPGD technology is sped-up, because fewer people are waiting to use it, or delayed

because more people are interested in using PPGD before the policy reversal. While it is possible

that the announcement of such a policy reversal would not affect the timing and selection of ovum

and spermatozoa, the chances here for ABCD seem diminishingly small. Again, this is not to say

that a policy reversal after ABCD are created is not to their benefit, but it is to say that planning

such a policy reversal is almost certainly not to their benefit. So, while we can acknowledge the

25 As we noted above, only a few hundred embryos have been adopted out of a pool of hundreds of thousands.

21

theoretical possibility that an unforeseen policy change might be to the benefit of BCD, for all

practical purposes this theoretical possibility is of little interest. At T1, the practical policy options

are either to permit PPGD or prohibit it. Permitting PPGD at T1 does not harm the embryos created

through this process, and indeed, may even be said to benefit them.

There are two consequences of the argument worth noting. First, the conservative view that a

policy of PPGD should not be instituted because it harms the embryos created is mistaken.26 Thus,

the argument here may help address some of the reasoning (or rhetoric) deployed by conservatives,

e.g., embryos are sometimes referred to as “microscopic-Americans” and some forms of assisted

reproduction, including PPGD, are said to harm microscopic-Americans. However, if the argument

here is correct, the microscopic-Americans (and international embryos) are not harmed by a policy

that permits PPGD. The extended version of the argument—not only does PPGD not harm embryos

created through this process, but actually benefits them—speaks to present policy in a number of

nations that prohibits procedures that are not of benefit to embryos. If the sole reason to prohibit

PPGD is that it does not benefit the embryos created through this process, then prohibition of PPGD

is wrong.

Second, as noted above, PPGD raises a number of ethical concerns that go beyond the harms or

benefits to the embryos created, so it would be premature to think that the fact that embryos are not

harmed by PPGD implies that PPGD is permissible. What the argument does show is that any

protest against PPGD will have to be located elsewhere. One possibility is to invoke non-person

affecting principles, e.g., maximizing aggregate utility or perfection. Suppose it can be shown that

there will be less or more aggregate happiness if PPGD is adopted as policy. Such a result would

provide us with utilitarian reasons for or against permitting PPGD, but this is non-person affecting

reasoning (Parfit 1984). Another possibility is to appeal to person-affecting considerations that do

26 I believe a similar line of argument can be used to show that PGD often does not harm in the case of negative selection, but obviously this is not the place to pursue this line of thought.

22

not apply to embryonic persons created through PPGD, e.g., suppose it can be shown that PPGD is

harmful to women because of the difficulty in ova procurement, or PPGD will tend to devalue those

who exist created through coitus, or that PPGD is good because it allows us to honour parental

rights to reproductive autonomy etc. All such reasoning does not address the harms or benefits to

ABCD. So there is at least the possibility of much more agreement between conservatives and

liberals on the issue of PPGD than first may be apparent.27

27 I would like to thank two anonymous referees for a great number of insightful and helpful comments on earlier versions.

23

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