Subway posters, a $30,000 package and promises of a smarter, taller child
The campaign crystallises a new phase in reproductive technology: companies that combine whole‑genome sequencing, machine learning and so‑called polygenic scoring to tell parents which of their IVF embryos has the highest predicted chance of certain health outcomes or visible traits. The offering sits between traditional preimplantation genetic testing, which looks for single‑gene disorders and chromosomal abnormalities, and the far more controversial idea of editing embryos' DNA.
What firms are selling and what they can credibly deliver
Nucleus advertises an "IVF+" programme — a bundled service that includes sequencing both parents and up to 20 embryos and producing polygenic scores that rank embryos on dozens or hundreds of traits. It is not alone. Silicon Valley and other hubs now host several companies offering polygenic embryo screening, from firms that position themselves as risk‑reduction tools for disease to others that explicitly say height or cognitive performance can be part of the conversation.
In practice, there are clear technical limits. Polygenic scores aggregate the tiny effects of many DNA variants to estimate an individual's genetic predisposition for a trait, but those estimates are probabilistic and noisy. For many medical conditions the signal is weak and depends on ancestry, environmental context and how well the underlying genetic studies were done. For behavioural traits like intelligence, the best current estimates suggest any boost achieved by choosing between a handful of embryos would be measured in a few IQ points at most — and those points are far from deterministic.
Researchers and clinicians who study reproductive genetics emphasise two further constraints. First, most large genetic studies have been done in people of European descent; scores built from those datasets perform poorly when applied to individuals with different ancestries. Second, genetic variants often have pleiotropic effects — a variant that slightly reduces risk for one disorder may increase risk for another — creating trade‑offs that are difficult to predict or present cleanly to prospective parents.
Criticism, regulators and the politics of marketing
The subway ads prompted swift pushback from genomics researchers and bioethicists who called the claims misleading and the marketing tone irresponsible. Scientists at established research centres, including the Sanger Institute and some academic medical centres, publicly decried what they described as overstating what polygenic prediction can deliver and glossing over the science's uncertainties.
Critics use words such as "misuse of science" and "snake oil" to describe companies that package early, population‑level statistical results into consumer products aimed at selecting embryos. That concern is not only scientific but ethical: selecting embryos based on probabilistic scores raises questions about the destruction of viable embryos, unequal access to these expensive add‑ons, and the possibility of a market that normalises choosing children by predictive metrics rather than treating reproduction as an open, uncertain process.
Regulatory patchworks complicate matters further. Some start‑ups have structured terms of service to avoid operating where specific licences are required. At least one firm acknowledged in public materials that it could not accept DNA from certain jurisdictions because of licensing rules. In many countries, laws and professional guidelines governing what embryo testing can be used for lag behind the technology, creating a vacuum that companies and wealthy early adopters are filling.
Where the money and momentum come from
Investment is a major driver. Venture capital and wealthy individual backers have funded companies that promise to extend IVF from infertility treatment into deliberate genetic optimisation. That funding accelerates research, commercial rollouts and promotional campaigns, but it also raises a conflict: firms with an incentive to expand markets may underplay the limits and overstate the certainty of their predictions.
Gene editing versus selection: two different futures
Alongside embryo selection, a separate strand of activity seeks to edit embryos' genomes — changing DNA rather than choosing between existing embryos. Editing is technically more complex, ethically riskier and in many jurisdictions legally restricted or effectively banned. Nevertheless, some well‑funded ventures are pursuing gene correction approaches in animals and planning preclinical work that, if successful and permitted, would eventually move into human embryos.
Selection and editing are not the same: selection merely ranks existing embryos with natural genetic variation, while editing would alter a descendant's heritable DNA. Both raise difficult questions, but editing intensifies concerns about unintended effects, germline alteration, and the moral threshold for making changes that will be passed to future generations.
What parents, clinicians and regulators might do next
For now, the immediate consequence is social and clinical: clinics and start‑ups are offering options that many prospective parents find attractive because they promise some control over risk and outcome. For families with a history of devastating single‑gene diseases, genetic testing and selection can already make a clear, measurable difference. For cosmetic or behavioural traits, the science is far less settled.
Several paths could help manage the transition. Clinics can tighten what they offer and demand clearer, independent evidence before translating polygenic estimates into clinical recommendations. Professional societies can update guidelines about which traits are appropriate to screen for and how results should be communicated. Regulators could require independent validation studies and better disclosure of predictive uncertainty. And public debate needs to consider social effects: who will have access to these services, how selection shapes notions of parental responsibility, and whether normalising genetic choice risks reviving historical ideas about eugenics under a modern commercial logic.
In the meantime, glossy subway posters and dramatic taglines will not alter a basic scientific fact: genomes provide probabilities, not guarantees. How society chooses to interpret and act on those probabilities will be the test — and the challenge — of the coming years.
Sources
- Sanger Institute (genomics research commentary)
- Harvard Medical School / Dana‑Farber Cancer Institute (academic experts)
- University of Utah (genomics and ethics commentary)
- Stanford University (IVF and bioethics researchers)
- medRxiv preprint (company validation study of embryo selection methods)
- JAMA Network and peer‑reviewed literature on chromosomal abnormalities and miscarriage
