{"id":391724,"date":"2025-09-02T11:04:10","date_gmt":"2025-09-02T11:04:10","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/391724\/"},"modified":"2025-09-02T11:04:10","modified_gmt":"2025-09-02T11:04:10","slug":"designer-babies-should-you-try-embryo-selection-via-polygenic-testing","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/391724\/","title":{"rendered":"Designer babies: Should you try embryo selection via polygenic testing?"},"content":{"rendered":"

Your Mileage May Vary<\/a> is an advice column offering you a unique framework for thinking through your moral dilemmas. It\u2019s based on value pluralism<\/a> \u2014 the idea that each of us has multiple values that are equally valid but that often conflict with each other. To submit a question, fill out this anonymous form<\/a>. Here\u2019s this week\u2019s question from a reader, condensed and edited for clarity:<\/p>\n

My partner and I did IVF recently and luckily we ended up with several embryos. One of those will be implanted in me so I hopefully get pregnant. But which one?<\/strong><\/p>\n

My fertility clinic is encouraging me to do PGT-A testing, which would screen for things like Down syndrome and would also let me see the sex of each embryo so I could potentially choose whichever I want. (And to be honest, I really want a girl!) I\u2019m also hearing about these new companies that can test embryos for all kinds of things \u2014 like how smart the kid might be, how tall they\u2019ll get, and whether they\u2019ll have a lower chance of getting breast cancer, diabetes, mental illness, stuff like that.<\/strong><\/p>\n

I don\u2019t know how to feel about any of this. On the one hand, it feels weirdly eugenics-y to do so much tinkering with embryos, and I can\u2019t help feeling a little pressured into overmedicalizing everything with these expensive tests. But then again, if I could do something to make my baby healthier and happier, don\u2019t I kind of have to do everything in my power? What does a parent owe their child?<\/strong><\/p>\n

This is such an exciting \u2014 and also confusing \u2014 time. You\u2019re about to have your first kid, and that comes with all sorts of fears and insecurities and hopes and dreams. You want to do the right thing \u2014 no, the best thing! \u2014 for your child. It\u2019s a beautiful impulse. Unfortunately, it makes it easy for companies to prey on you.<\/p>\n

So let me walk you through what these companies can and can\u2019t really provide. After we talk about the science, we can talk about the ethics.<\/p>\n

The simpler test you mentioned, PGT-A, has been around since the 1990s. It can indeed screen for conditions like Down syndrome and let you see the sex of each embryo. Mind you, that doesn\u2019t predict what gender your child will ultimately end up identifying with \u2014 more on that soon.<\/p>\n

The newer testing you mentioned is called polygenic testing. The conditions it screens for are complex ones, influenced by thousands of genes. We\u2019re talking about everything from breast cancer to depression. Some companies even offer screenings not for disease prevention, but for genetic enhancement \u2014 so you can select for a taller kid or a kid with higher IQ.<\/p>\n

Polygenic testing companies claim to predict each embryo\u2019s risk for each condition, and the potential reduction of risk you\u2019ll get if you choose one embryo over another. As the statistical geneticist Sasha Gusev explains<\/a>, it\u2019s very, very easy to be misled by this claim. If the company claims to lower absolute risk of Type 2 diabetes by 12 percent, you might think this means, \u201cThe chance of my kid ever developing diabetes just went down by 12 percent \u2014 great!\u201d But really what it means is that, all else equal, a kid who would\u2019ve developed diabetes is likely now at the high end of pre-diabetes instead, or just develops diabetes a few years later. The same holds true for other conditions, like breast cancer. Sure, if your kid is going to develop diabetes or breast cancer, you\u2019d rather they develop it later \u2014 but it\u2019s not the bill of perfect health customers might imagine.<\/p>\n

\u201cTypical risk reduction estimates tend to exploit statistical assumptions to overstate their benefits and lead to confusion,\u201d Gusev writes.<\/p>\n

Have a question you want me to answer in the next Your Mileage May Vary column?<\/strong><\/p>\n

It\u2019s also important to note that there\u2019s a difference between a physical disease like cancer, which is straightforwardly and universally negative, and a complex mental health condition like depression. For one thing, polygenic scores don\u2019t perform as well in psychiatry<\/a>, as psychologist Eric Turkheimer notes. Plus, most mental health conditions come in mild to moderate to severe forms, and it\u2019s not clear that we should want to get rid of mild or moderate manifestations.<\/p>\n

\u201cSure, it would be nice if no one ever got depressed, but what would that actually mean?\u201d Turkheimer writes. \u201cPeople are going to be sad, and the most modern models of psychiatric disorders view most of them as extremes on continuous dimensions of normal behavior. I don\u2019t think we want some kind of genetic version of Soma<\/a>.\u201d<\/p>\n

To give a personal example: I have generalized anxiety with some obsessive tendencies. Is that a major pain in the butt sometimes? You bet. But if I could wave a magic wand and get rid of it, would I? No. In my experience, this trait is linked to another trait I deeply value: my creativity. The same thing that propels me down rabbit holes of worry also propels me down rabbit holes of getting super curious about some topic, researching it into the wee hours of the morning, and then writing a novel or children\u2019s book about it.<\/p>\n

That brings me to one other scientific issue: pleiotropy. It\u2019s a fancy term for a simple truth, which is that genes can have an effect on more than one trait. When it comes to behavioral polygenic testing, we actually know very little about which genes cause what \u2014 a gene that\u2019s correlated with depression or anxiety may also be correlated with a bunch of other things. So, if everyone were to start selecting embryos to try to protect their kids from depression or anxiety, what would happen? We don\u2019t know!<\/p>\n

Pleiotropy is a scientific issue, but it\u2019s also a moral issue, because in trying to protect your kid from a negative outcome, you could also be accidentally barring them from a positive one.<\/p>\n

And that\u2019s just the tip of the moral iceberg.<\/p>\n

Another issue is the potential psychological harm that can result from commodifying our kids \u2014 treating them like consumer objects with selectable parts. Let\u2019s say you use polygenic testing to try to select for high IQ. Even if the company\u2019s predictor is right 80 percent of the time, that means it\u2019s wrong 20 percent of the time. What happens if it\u2019s wrong about your kid, and they end up with a low IQ instead of a high one? How will your kid feel? Unless you hide the truth from them, they\u2019ll know that they are not what you wanted, that they failed to live up to the vision you went out of your way to chase.<\/p>\n

The same goes for sex selection via good old PGT-A. I know you really want a girl. But what would happen if you select for a girl, and then your child grows up and turns out to be trans? They may feel an extra sense that they\u2019re letting you down by not conforming to the gender expectations you had for them.<\/p>\n

Then there are the ethical questions around unequal access. Polygenic testing isn\u2019t cheap. (One company, Orchid, charges $2,500 per screened embryo. Test 10 embryos and that\u2019ll cost you $25,000.) So, at least in the short term, that raises the specter of entrenching a caste system, where the gap between rich and poor expands dramatically as the rich get smarter and stronger.<\/p>\n

Technologies tend to get cheaper over time, so maybe everyone will ultimately be able to afford polygenic testing. But that raises another problem: implicit coercion. If more and more of us make ourselves smarter and stronger, we may create a society in which everyone feels pressure to alter their child\u2019s biology \u2014 even if they don\u2019t want to. To refuse embryo selection would mean to put a child at a huge professional disadvantage, or to face moral condemnation for making \u201csuboptimal\u201d kids when optimization is possible. Society may no longer offer health insurance benefits or accommodations for kids with disabilities (or even non-enhanced IQ), reasoning that \u201cit was the parents\u2019 choice.\u201d<\/p>\n

Some philosophers, like Julian Savalescu, already argue that parents have a \u201cmoral obligation to create children with the best chance of the best life<\/a>.\u201d Polygenic testing companies love that argument; Orchid founder Noor Siddiqui tells parents<\/a> that \u201cthe responsible decision\u201d is to \u201cprotect their children\u201d from disease, using language like, \u201cWhat if you could have stopped it…but chose not to?\u201d And we generally live in a culture that\u2019s obsessed with optimization<\/a>.<\/p>\n

So it\u2019s no wonder that you find yourself asking, \u201cIf I could do something to make my baby healthier and happier, don\u2019t I kind of have to do everything in my power?\u201d<\/p>\n

It\u2019s a view that will be very appealing to utilitarians, who believe the right action is the action that maximizes well-being or happiness. But maximizing principles can be dangerous. If we\u2019re laser-focused on maximizing one value, however noble it may be, that can lead us to overlook a host of other important values. Think about diversity, for example; polygenic testing could lead to a less diverse world.<\/p>\n

And it\u2019s not even clear how to maximize well-being given that each embryo will have some downsides: How would you choose between one embryo with a slightly elevated risk for schizophrenia, another with a moderately elevated risk for cancer, and a third with a high risk for Alzheimer\u2019s? You\u2019d have to decide how to rank the importance of each condition, which would require a dizzying bit of moral math: How much weight do you put on the longevity associated with each condition, how much on patient-reported quality of life for each condition, and how much on your own ability to cope with each \u2014 and society\u2019s ability (which will change over the years)? Plus, even if the screening does end up optimizing life for your individual child, it could have negative effects on the population level, for the reasons we covered above.<\/p>\n

As Nobel laureate Herbert Simon pointed out, many problems contain way more variables and way too much uncertainty for maximizing along a single axis to be feasible or even desirable. So it often makes sense to just go with an option that\u2019s \u201cgood enough.\u201d He coined the term \u201csatisficing\u201d \u2014 a portmanteau of \u201csatisfying\u201d and \u201csufficing\u201d \u2014 to describe opting for this good enough choice.<\/p>\n

What would satisficing look like in the context of embryos? If there\u2019s a very serious condition that runs in your family \u2014 like Tay-Sachs or the BRCA mutation that markedly increases cancer risk \u2014 then I do think there\u2019s a strong case for screening for that. These conditions are debilitating and can lead to early death. Nobody wants them. Genetic testing that lets us prevent them is an awesome gift.<\/p>\n

Then there are conditions that can include suffering, like autism, but can also be very compatible with a happy life. Mental health conditions in particular are heavily socially constructed \u2014 a lot of the associated suffering comes about because society constructs a certain biological reality as a problem and doesn\u2019t support the people who have it. In these cases, if you want to give your child a \u201cgood enough\u201d or even \u201coptimized\u201d life, remember that you don\u2019t have to achieve that by biological means; working to change the social environment can be just as important, and it doesn\u2019t carry the societal risks associated with polygenic testing.<\/p>\n

Ultimately, when considering what counts as a \u201cgood enough\u201d life, each parent will draw the line in a slightly different place. And there\u2019s a part of that that can\u2019t be boiled down to objective facts about disease, because this is also about how well-resourced the parent feels \u2014 emotionally, socially, and financially \u2014 to deal with a certain condition. What feels manageable to one parent may feel crushingly hard to another.<\/p>\n

So, I can\u2019t tell you exactly which screenings to do and which to forgo. What I do want to tell you is to resist being bullied or shamed by others, especially those with a profit incentive to push you in a certain direction.<\/p>\n

As the epidemiologist Abby Lippman has noted, genetic testing is supposed to offer parents<\/a> more choice, but it too often has the opposite effect. When someone like Orchid\u2019s Siddiqui says about a disease, \u201cWhat if you could have stopped it…but chose not to?\u201d \u2014 well, that language preys on parents\u2019 worst fears and insecurities. It holds parents hostage while pretending to be giving them more autonomy.<\/p>\n

You are nobody\u2019s hostage. You are a moral agent free to look at the many different relevant factors, weigh them all in the balance, and then make the choice that works well enough for your family.<\/p>\n

Bonus: What I\u2019m reading<\/p>\n