New York Times writes about “In Choosing a Sperm Donor, a Roll of the Genetic Dice”: recipients of sperm donation have found out the hard way that there is a risk of genetic disease affecting their children. In at least one case a donor with a clean bill of health and who had, according to the laboratory, been tested for genetic conditions. Unfortunately he turned out to be a carrier for cystic fibrosis like the mother, and the child suffered. Other cases of transmission of genetic conditions to multiple children from a single donor have appeared, suggesting a need to do something. Is there an ethical need for ensuring genetic testing in the case of sperm donation – or is the problem that some donors father many children?
Proper testing
An obvious moral issue is the fault of the sperm bank that claimed they provided tested sperm. They in turn purchased it from another bank that claimed they have tested it properly. But this is a fairly standard issue of making false claims and not checking the sold product, although the consequences where large. Clearly the proper thing to do is to run genetic testing and make sure the results are correctly interpreted. Establishing a better national donor registry of gametes and making it possible to report back genetic disorders so that gamete lines can be removed also seems to be a sensible approach to retrofit the existing US system in the light of apparently unreliable testing.
Why test in sperm donation?
Is there an ethical need for genetic testing in the case of sperm donation? There is not any greater risk of getting a genetic disorder from a sperm donor than anybody else.
But there is one good reason: since sperm donors can father far more children (up to 150, according to the article) a donor with alleles predisposing to a genetic condition can spread them far and wide. This is not a problem for egg donation.
The article makes it sound like every donor becomes the father of a big dynasty, but this is not true. In many places there are laws or regulations of sperm banks about the allowed number of offspring (often citing worries about consanguinity in later life). For example, in the UK only 10 families can be created with gametes of one donor. Presumably under situations of free choice (such as with US sperm agencies or private donors) the Matthew effect might play a role: a donor with unusually positive traits (and perhaps also success in achieving fertilisation) would tend to have far more offspring than the less desirable ones, who might never be selected at all.
The size of the impact of spreading bad genes becomes much larger if you are the father of 50 children rather than 2. Concerns of depleting or polluting the gene pool are fairly irrelevant (since relatively few children are produced by donor sperm compared to the normal method, and it is not clear that the gene pool itself holds any moral value). But there is a predictable individual impact on the children that will result. The disbenefit is mainly theirs.
The principle of procreative beneficence suggests that if you have a choice you should go for the children most likely to have the best life: this clearly implies that parents and sperm banks ought to screen the sperm for life-impairing conditions. Donors also likely don’t want their offspring to suffer (the article mentions how a donor who spread hypertrophic cardiomyopathy apologized to one of his children, saying he felt horrible for giving him the disease). They would hence also have a good reason to want to screen themselves. The exception would be, if what they actually desire is having more biological offspring rather than just help childless couples. Then the principle would not apply (since the children being genetically related to the father is the goal), but I suspect most people would find this view of spreading one’s genes rather selfish and unempathic.
Selfish genes vs. human values
Is there anything ethically wrong with having lots of genetic children? It certainly satisfies selfish genes, and might hence drive some people.
The problem is that genes do not have any ethical weight, but people and their experiences do. A father of 150+ will be genetically successful, but genetic success is very little of what makes a human life go well by most accounts. It doesn’t take much personal excellency to donate sperm, and if other people then rear one’s children one cannot have said to contributed much to their lives except part of their genetic foundation. It seems rather lazy, in fact.
One might claim that helping 150+ childless couples is a good thing, but they could have been helped equally well by other donors: it is the donating that matters, not how much of one’s sperm actually gets used.
Having plenty of offspring might be a good thing if one has good reasons to think one has exceptionally useful genes that would be beneficial to people if they got spread, but I suspect that few donors have actual grounds to believe this. In fact, if there are genes predisposing for wanting to donate a lot – perhaps via narcissism, for example – they might spread this way.
One reason against having lots of children might be that one is taking “space” from less prolific parents. Maybe there should be an “equality of opportunity” for genetic fitness? But again the moral value of genes is much less than the value of human lives: genetic fitness doesn’t seem to be enormously valuable, or we would be clamouring for having bigger families. In the case of sperm donation there is also the issue of infertility: the males “crowded out” by the donors are either infertile or non-existent (in the case of lesbian couples). Nobody gets harmed. Compare that with polygamy, where certain people get a chance to monopolize partners, gaining all the emotional, social and indeed genetic benefits at the expense of others.
As far as I can tell, there are no strong arguments for or against having lots of genetic children; personal autonomy of the involved people seems to outweigh all of the above arguments. However, the impact of even a small risk amplified across many human lives can become large. People wishing to have lots of offspring in a moral better make sure they are not causing these children bad lives.
What about normal couples?
If one really ought to screen in sperm donation, should one not also screen in normal reproduction? It seems that there is a balance here of the desire (or obligation) to minimizing risks and the desire for a child related to both parents (who, unlike the above fitness-maximising sperm donor, will be actually living with and loving the child, getting over the selfishness objection). In the case of fertile couples that have risk of problematic genetic conditions there exist solutions such as PGD, that would allow couples to have risk-safe children with each other: problematic screening results does not mean they cannot have children. It seems to me that screening could be helpful even in normal reproduction unless the costs/pressures of handling genetic risk turns out to be very large.
New families
Although there are downsides to donors with large groups of descendants (risks of consanguineous relations, the genetic issues) there might be benefits too. Apparently contact among families sharing the same donor can be beneficial, giving children an extended family and identity. The ability to network among gamete recipients seems to have been one factor that made the genetic risks come to light: it might be that allowing these new forms of relatedness enabled by biomedicine and information technology to flourish will allow them discover other things of value.
We might have an instinctive emotional reaction to men siring 150 children (perhaps even motivated by some evolutionarily motivated ‘fitness envy’), but what actually matters is that they are desired children that will grow up in families: the genes don’t matter that much, except when they are faulty.
How long would it take for evolutionary pressure to have an impact if some sperm donors get such large descendance? If it’s only more than a few generations, there probably is little impact, but is it?
The time to fixation of a gene giving a fitness advantage s in a population N is ln(N)/s. So if being a prolific sperm donor was 100% genetic and they have 10 kids compared to the usual 2.1 if they are males, then the average fitness would be (0.5*2.1 + 0.5*10)/2.1 = 2.88. The fitness advantage is 1.88 (huge by normal genetic standards!) and the time to spread in a population numbering around 300 million (the US) would be 10.4 generations. Something like 260 years.
I suspect cultural and technological evolution will be much more significant on that timescale. Especially as prolificness is likely just genetic to a small degree.
Oh, a small typo: the formula should be 2 ln(N)/s. So the time would be 20.8 generations, 520 years.
Hmm, might want to reconsider using “normal couples” in such large text – as opposed to those freakish couples who are, say, gay or infertile?
> unless costs/pressures of handling genetic risk turns out to be very large.
When it looked like my partner might have a genetic disease, we looked into what it would cost to select healthy embryos: $15,000 per treatment (and no guarantee you’ll get pregnant on the first treatment). Ouch. You can increase the chance of pregnancy by implanting multiple embryos, but then you’re more likely to have multiples who then have other health risks.
Normal couples: Ah, slip of the keyboard. Although it is not clear how that section makes sense when talking about screening in gay or infertile couples – I guess the proper heading should be “What about non-insemination reproduction?”
Cost: yes, right now those costs are pretty atrocious, like most medical costs. But this is an area where we can expect costs to come down as technology matures (but, unfortunately, since it is a professional service, limited by the salaries of the people doing it).
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