How the technology that allows "selecting" embryos challenges our ethics, access, and collective future
Date: August 21, 2025
Imagine being able to prevent your future child from inheriting a serious genetic disease. Or selecting, from several embryos, the one with the highest probability of a healthy life. This, which until recently was science fiction, is today a medical reality thanks to Preimplantation Genetic Testing (PGT).
PGT is a procedure performed during in vitro fertilization (IVF) treatments. It allows genetic analysis of embryos before they are implanted in the uterus, identifying those with chromosomal abnormalities or specific genetic mutations linked to serious diseases 1 .
But this powerful technology does not come alone. It brings with it a whirlwind of ethical, legal, and social questions. Are we moving towards truly "personalized" medicine or towards a new form of privatized eugenics? Who has access to these technologies and who is left out?
This article explores the fascinating and complex world of PGT, a field where biology intertwines with ethics, the private clashes with the public, and the future of collective health is redefined.
PGT allows screening for chromosomal abnormalities and genetic mutations before implantation.
The technology raises profound ethical questions about selection, access, and equity.
PGT is not a single test, but a set of technologies. To understand it, it's crucial to know its three main variants, each with a distinct purpose:
Analyzes chromosome number. Aneuploidies (an extra or missing chromosome) are a main cause of implantation failure, spontaneous abortions, and syndromes like Down's. Its primary goal is to increase the efficiency of IVF treatments.
Detects specific mutations in individual genes. Used when parents are carriers of hereditary diseases like cystic fibrosis, hemophilia, or Huntington's disease.
Aimed at parents who are carriers of structural chromosomal rearrangements (like translocations), which can cause embryos with genetic imbalances.
Eggs and sperm are obtained to create embryos in the laboratory.
When the embryo reaches the blastocyst stage (day 5-7 of development), 5 to 10 cells are delicately extracted for analysis.
The cells are analyzed using next-generation sequencing technologies (NGS).
Only embryos diagnosed as genetically "normal" or free of the specific mutation being sought are transferred to the uterus of the gestational person.
A crucial "experiment" doesn't happen in a laboratory, but in society. Argentina offers a paradigmatic case study on the implementation of these precision technologies in a context of collective health 1 .
The procedure develops in a particular regulatory environment:
Enactment of Law 26.862 on Comprehensive Access to Medically Assisted Reproduction Procedures and Techniques. This law made Argentina a pioneer country by guaranteeing mandatory coverage of assisted fertilization treatments.
Reform of the Civil and Commercial Code, which incorporated filiation through assisted reproduction techniques.
Despite this enabling framework, there is no specific regulation on the use of PGT. Critical issues such as the legal status of cryopreserved embryos, cryopreservation deadlines, and crucially, the inclusion of PGT in the Mandatory Medical Plan (PMO) for its coverage, were left unresolved 1 .
This social experiment has yielded mixed and profoundly contradictory results:
Growth of PGT usage in the region between 2014-2018 1
| Aspect | Covered by Law 26.862 | Not Covered/Regulated (Legal Vacuum) |
|---|---|---|
| IVF Procedures | Yes | - |
| Medication for the cycle | Yes | - |
| Cryopreservation of gametes/embryos | Yes | Deadlines and final destination |
| Preimplantation Genetic Testing (PGT) | No | Its coverage is not mandatory; it is left to the discretion of each health insurance/provider. |
| Legal status of the embryo | - | There is no specific law that defines it. |
PGT would be impossible without a sophisticated set of reagents and technologies. This is the toolbox that makes the miracle possible.
| Reagent/Tool | Function in the Process | Scientific Importance |
|---|---|---|
| Specialized Culture Media | Support embryo development to the blastocyst stage. | Mimic the conditions of the fallopian tubes and uterus, providing critical nutrients and growth factors. |
| Trophectoderm Biopsy Solution | Allow precise dissection of a cell group from the blastocyst. | Minimizes damage to the embryo (which continues developing) compared to old single-cell biopsies on day 3. |
| DNA Amplification Kits (WGA) | Amplify the entire genome from the few cells obtained in the biopsy. | Generates enough genetic material to perform multiple tests from a tiny sample. |
| Next Generation Sequencing (NGS) Probes | Sequence millions of DNA fragments in parallel and massively. | Allows simultaneous analysis of all chromosomal aneuploidies (PGT-A) and specific mutations (PGT-M) with high precision and decreasing costs 2 . |
| Bioinformatic Analysis Software | Analyze the huge amount of raw genetic data produced by NGS. | It is the "brain" of the process; identifies genetic variants, interprets them, and generates a report understandable for the physician. |
Declining cost of genetic sequencing over time (2001-2025) 2
Precision medicine, which seeks to personalize interventions based on individual genetic variability, seems to come into tension with the principles of collective health, which prioritizes actions on populations and social determinants of health 1 .
| Precision Medicine Paradigm (via PGT) | Collective Health Paradigm |
|---|---|
| Focus on the individual and their genome. | Focus on the population and its socio-environmental conditions. |
| Technical personalized intervention (embryo selection). | Political and social intervention (improving access to potable water, education, nutrition). |
| Logic of optimization and reduction of biological uncertainty. | Logic of equity and social justice in health access. |
| High technological cost, potentially generating inequalities. | Prioritizes cost-effectiveness and benefit for the majority. |
| Risk of genetic determinism (believing everything is "written" in the genes). | Recognizes the multicausality of diseases (genetics, environment, society). |
The risk is that PGT becomes a luxury for a few, deepening the gap between those who can "optimize" their children's health and those who cannot, medicalizing and geneticizing inequalities that are fundamentally social 1 .
A genetic result doesn't only affect the individual. As discussed in the American context, PGT information can be relevant for siblings, cousins, and other relatives who share genetic burden. Does the physician have the obligation to alert at-risk relatives if the patient refuses to do so? Jurisprudence is ambiguous and confidentiality dilemmas are enormous 3 .
When selection stops being oriented toward avoiding serious diseases and opens the door to selecting non-pathological characteristics (like sex or perhaps in the future other traits), the technology enters ethically murky territory.
Preimplantation Genetic Testing is a powerful technology that offers tangible hope to thousands of families to avoid the suffering of devastating genetic diseases. Its potential to alleviate the burden of uncertainty and pain is undeniable and must be recognized.
However, its development cannot be left solely to the market, to individual logic, or to the uncritical import of debates from other latitudes ("the North") 1 . To prevent it from becoming another factor of inequality, it is urgent to:
The future that PGT helps bring into the world should be a future chosen by everyone, not just a few. And that choice begins with an informed, honest, and collective conversation today.
Note: This article is based on scientific literature and current debates in bioethics. The views expressed are for informational purposes and do not constitute medical or legal advice.
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