The emergence of services like Nucleus Genomics, which offers expectant parents the opportunity to choose the embryo with the longest life expectancy, has set off alarm bells in the field of bioethics. Based on polygenic scoring algorithms, this procedure applies market logic to the very beginning of human life, making genetics a selection criterion. Although presented as a breakthrough in preventive medicine, experts warn that we are facing a new bioethical dilemma, where the dignity of the embryo, social justice, and the limits of biotechnology are seriously threatened.

Biotechnology is once again pushing the boundaries of ethical debate. The American company Nucleus Genomics, led by Kian Sadeghi, has launched a controversial service that allows future parents to select embryos with longer life expectancies based on advanced genetic analysis. The initiative, currently available in countries with permissive assisted reproduction legislation, promises to assess the risk of aging-related diseases and guide the selection of the “healthiest” embryo. The cost of the procedure: $6,000 (approximately €5,300).

The news has sparked intense debate among scientists, health professionals, and bioethics experts, especially in Europe, where practices like this are illegal in most countries, including Spain.

A selection based on genetic algorithms

In vitro fertilization (IVF) is essential for this procedure, but it also includes an additional layer: polygenic risk assessment. Nucleus analyzes multiple genetic variants associated with chronic diseases such as Alzheimer’s, cancer, type 2 diabetes, and heart disease, with the goal of estimating which embryos are most likely to live longer and in good health.

These analyses are based on what is known as a polygenic risk score, a developing statistical model that combines hundreds or thousands of small genetic variants to calculate predisposition to certain complex diseases. While this is a tool with potential for preventive medicine, its application in embryos raises serious ethical, scientific, and social questions.

Criticism from the scientific community

Many experts have reacted with skepticism.  Dr. Marc Güell, professor of synthetic biology at Pompeu Fabra University (Barcelona), has stated that “we cannot predict how long a person will live based on their genetics alone.” Longevity, he asserts, depends on many non-genetic factors: environment, lifestyle habits, quality of medical care, and even chance.

A new study based on data from the UK Biobank, which analyzed more than 490,000 people, adds that environmental and lifestyle factors have a significantly greater impact on disease and mortality risk than genetics.

The authors of the study, published in Nature Medicine, have analyzed the influence of more than 100 environmental and genetic factors   on aging and mortality, revealing that the key to a long and healthy life could lie more in habits than in DNA.

Furthermore, from the field of bioethics, it is worth noting that the use of preimplantation genetic diagnosis (PGD) in Spain is strictly regulated. It is only authorized to prevent serious, early-onset monogenic diseases, not to enhance traits or select for characteristics such as longevity.

It is also noted that this practice entails a risk of genetic discrimination, by introducing the idea that some embryos are “better” than others based on future health criteria, without any real guarantees.

A new form of eugenics?

Although Nucleus insists its service doesn’t guarantee any specific results, the implicit message is troubling: “Pay, and your child could live longer.” This approach, critics say, paves the way for the idea of ​​”baby catalogs” and a form of soft eugenics, in which only those who can afford these services will access the supposed genetic optimization.

The ethical and social consequences are profound: it reinforces the instrumental view of the human embryo and threatens the principle of equity in access to health care. As the French National Ethics Commission has warned, practices like this could “blur the line between medicine and social selection.”

Where is this type of selection legal?

The Nucleus Genomics service cannot be offered in most European countries. In Spain, the Assisted Human Reproduction Act expressly prohibits genetic selection except for therapeutic purposes to correct serious abnormalities. The same is true in France, Germany, Italy, and Norway.

However, there are legal gray areas in countries like the United States, where regulation depends on the individual states and where commercial genetic selection has begun to grow without a clear federal regulatory framework. Lax practices have also been identified in countries like Mexico and Ukraine, which have become destinations for fertility services that are difficult to regulate.

The bioethical challenge: respecting the dignity of the human embryo

The Nucleus Genomics proposal, beyond its technical feasibility, represents an urgent challenge for contemporary bioethics. What place does the dignity of the embryo have in the face of the wishes or fears of the parents? Are we entering a market logic where genetics becomes a new consumer good?

From a bioethical perspective, embryo selection based on longevity probabilities—without conclusive scientific evidence and driven by commercial interests—puts at risk fundamental principles such as equality, justice, and the inviolability of human life from its very beginning.

More than a medical solution, this practice seems to point to an elitist model of reproduction, with serious social, health, and moral implications.

For Nicolás Jouvé , a genetics expert and member of the Bioethics Observatory, the main ethical issue in this type of practice is the loss of embryos, because they are human lives. “Any technology that works with embryos must take this into account. It’s impossible to speak of respect for life if we’re experimenting with embryos knowing that many of them will be destroyed because the outcome wasn’t what we expected or because some, due to poor handling, simply lose their ability to continue. That’s why there’s an established moratorium recommending against the use of embryos in this type of research.”

A step forward towards transhumanism

All genetic selection not only constitutes an attack on the right to life and dignity of individuals, regardless of their personal circumstances, but also constitutes an attack on the balance of the ecosystem. The experiences of sex selection in China, when the one-child policy was implemented, have caused a demographic crisis in that country with incalculable consequences that they are now struggling to reverse. The racially inspired genetic selection policies implemented under Nazism have led to unjustifiable genocides, true attacks on human nature and its intrinsic dignity. Selecting those who are healthy, long-lived, or better assimilated to certain patterns implies discarding those who are weak, vulnerable, dependent, or different. Many geniuses, thinkers, artists, and scholars have been vulnerable, sick, and weak people, and they have bequeathed incalculable treasures to humanity.

Julio Tudela – Cristina Castillo – Bioethics Observatory – Institute of Life Sciences – Catholic University of Valencia