A Dangerous Precedent? DNA Companies Offer Parents the Chance to Choose Embryos by Traits

A growing number of genetic-testing firms are marketing services that let parents undergoing in vitro fertilization (IVF) compare embryos not only for single-gene disorders but for a range of predicted traits — from eye color and height to estimated cognitive ability and risks for mental-health conditions.

Companies such as Nucleus Genomics say they will analyze embryonic DNA and deliver a trait profile to prospective parents. In promotional material released earlier this year, the firm framed the service as a way to give “parents a new window into the health and well‑being of their future child,” saying their Nucleus Embryo product provides “a comprehensive genetic profile for each embryo, encompassing hereditary genetic diseases, like cystic fibrosis and hemochromatosis, alongside genetic measures of cognitive ability, mental health, and risk for chronic diseases.”

IVF frequently produces multiple embryos, and clinicians already make choices about which to transfer based on viability and sometimes sex chromosomes. What companies like Nucleus and others now propose goes further: personalized assessments of many heritable traits and predispositions to complex conditions, offered directly to parents who can afford the add‑on testing.

The firms’ public materials list a mixture of classic single-gene conditions and polygenic or probabilistic traits. Alongside cystic fibrosis and hemochromatosis, promotional images and webpages show traits such as eye color, hair color, left-handedness, IQ and autism risk. Websites also mention restless legs syndrome, body mass index (BMI), male pattern baldness, alcohol dependence, obsessive‑compulsive disorder (OCD), depression, anxiety and severe acne.

Those offerings have intensified ethical concerns about where reproductive choice ends and eugenic selection begins. Earlier this year, Orchid — another company offering similar services — drew public attention partly because of reported connections to the family of a high‑profile entrepreneur. At the time, a bioethicist affiliated with Orchid dismissed the label “eugenics,” preferring the term “genetic enhancement.”

Investors have pushed the same line. Delian Asparouhov, a partner at Founders Fund who has invested in Nucleus, argued that many everyday parental choices are a kind of eugenics, saying that choosing a partner or investing in children’s education is comparable to using a tool to “amplify” desirable outcomes.

Critics say there is an important ethical distinction between selecting a life partner or providing educational opportunities and using genetic information to pick embryos. Choosing to screen embryos to avoid a serious, well‑understood monogenic disorder is different from ranking embryos by probabilistic measures of traits such as intelligence or the likelihood of autism.

There is also a scientific limitation: most common traits and many psychiatric diagnoses are polygenic — influenced by many genes plus environmental factors. Although studies can identify groups of genes that correlate with outcomes in populations, those correlations are probabilistic rather than deterministic. In plain terms, a higher genetic risk score does not guarantee a given outcome, and a low score does not guarantee its absence.

The American College of Medical Genetics and Genomics (ACMG) and other experts have warned against the clinical use of polygenic risk scores for embryo selection. They point out that current genetic research on complex traits is an inexact science, able only to estimate risk rather than identify affected individuals, and that offering such scores directly to consumers as a basis for embryonic selection is premature.

Beyond the scientific uncertainty, there are practical and financial realities. IVF is often costly and emotionally taxing; paying for additional genetic analyses can add tens of thousands of dollars to the process. For most prospective parents, that extra expense may offer little actionable benefit.

Doctors and genetic counselors remain the best sources for explaining which tests are clinically appropriate. Current screening can help identify embryos with conditions that would make implantation or pregnancy less likely to succeed or that would cause serious disease. Patients considering extended trait screening should discuss which conditions are realistically identifiable, and whether the predictions are reliable enough to guide decisions.

Ultimately, anyone contemplating paid embryo-trait profiling should reflect on their personal values and the science behind the claims before proceeding. Decisions about screening should balance ethical considerations, family priorities and honest assessments of what the testing can — and cannot — predict.