How genetic testing can drive a destructive child perfectionism and parenting arms race
Key points at a glance:
- Advanced embryo tests now claim to screen for intelligence and physical traits.
- Commercial clinics sell parents the illusion of absolute control over complex biology.
- However, polygenic predictions remain statistically weak and carry still-hidden genetic risks for children.
- Singapore must ban routine trait selection to prevent an ethically destructive commercial genetic arms race.
Imagine IVF embryo genetic testing so advanced that it can examine much of an embryo’s genetic blueprint, allowing prospective parents to screen for disease and choose traits for their children associated with intelligence, complexion, height, and athletic ability.
This is no longer science fiction. It raises a stark question: if offered the chance to choose the ‘best’ embryo, would parents feel entitled, or even obliged, to do so?
All parents want a bright future for their children, yet that understandable desire creates profound ethical problems when a commercial technology promises to reduce the randomness of reproduction itself. Preimplantation Genetic Testing with Whole-Genome Sequencing (PGT-WGS) represents a major expansion beyond conventional IVF genetic testing.
A Crystal Ball Made of Cells?
Companies in the United States already market genome-wide embryo-testing services to IVF patients. Some present the technology as a way to screen for hundreds of disease conditions; others invite parents to use polygenic scores to compare embryos for complex disease risks or traits.
The central question for Singapore is therefore not merely whether the technology can generate more data. It is whether this data is accurate, meaningful, and useful enough to justify the medical, financial, moral, and social consequences of acting on it.
The Leap Beyond Disease Testing
PGT-WGS begins with a blastocyst, typically a five-day-old embryo. A few cells are removed from the outer layer that largely forms the placenta and umbilical cord. Their DNA is amplified and sequenced to generate genome-wide information. In theory, one platform can incorporate functions now associated with several types of PGT:
- PGT-A, which screens for large chromosome-number abnormalities such as those associated with Down syndrome;
- PGT-M, which tests for a known single-gene disorder, such as beta-thalassaemia, in a family at risk;
- PGT-SR, which assesses embryos where a parent carries a structural chromosomal rearrangement; and
- PGT-P, the most controversial application, which uses polygenic scores to estimate susceptibility to complex diseases and to rank embryos for non-disease traits, including height or intelligence.
These uses should not be collapsed into one moral category. Helping a couple avoid transmitting a known, severe childhood genetic disorder is not the same as ranking embryos according to predicted educational attainment, stature, appearance, or athletic potential.
Whole-genome sequencing is a method of producing information. The ethical question is what is done with that information—and what parents are encouraged to believe it means.
Why the Market Is So Attractive
PGT-WGS arrives amid a ‘perfect storm’ of falling fertility and later parenthood. When parents have fewer children and spend vast sums to conceive them, the wish to eliminate every possible uncertainty becomes understandable. This compounds with Singapore’s kiasu (‘fear of losing out’) culture, alongside competitive education and the expectation that children will vindicate parental sacrifice and safeguard family standing.
The question then emerges: What if the unpredictability of sex and fertilisation can be overcome? What if you improve your chances of avoiding not only disease, but the embarrassment, anxiety, and loss of status associated with producing a child who does not meet family expectations?
Consumer-driven eugenics starts here. There is no need for state coercion or forced sterilisation of anyone ‘unfit’, because it’s enough to have a private market that encourages parents to rank prospective children according to their ‘portfolio’ of health, ability, appearance, and social desirability. It presents selecting the most ‘advantaged’ embryo, whatever this means, as responsible parenthood.
The pressure need not be explicit. A clinic need only ask: “You are already paying for IVF. Why not use every genetic advantage available?” To refuse the costly add-on sounds like gambling with their child’s future.
The Limits Behind the Hype
However, the industry needs to disclose the truth. First, an embryo biopsy is not a direct reading of the future child. The sampled trophectoderm becomes the placenta, while the foetus develops from the inner cell mass. An embryo may be mosaic: different cells may contain different genetic patterns. A result from a few outer cells may therefore not perfectly represent the developing foetus. Some embryos labelled abnormal or mosaic have produced healthy births.
Second, every layer of the procedure introduces uncertainty: biopsy, DNA amplification, sequencing, variant interpretation, freezing and thawing, and the translation of a genomic finding into a decision about which embryos should live, be stored, or be discarded. Whole-genome data can identify more variants, but many variants have uncertain significance. More information can create more ambiguity, rather than more clinical clarity.
Third, patients may trade pregnancy chances for an apparently superior genetic profile. The embryo that looks healthiest under the microscope may not rank highest on a genomic test; conversely, an embryo with an attractive score may have lower developmental potential. The sorting may actually not improve the outcome patients actually value: the cumulative chance of a healthy live birth.
This is especially significant because PGT-A itself remains controversial as a routine IVF add-on. Major professional and regulatory bodies have questioned whether broad application improves outcomes for most patients, and lawsuits have been launched over alleged wrongful disposal of possibly viable embryos. If established chromosome screening remains contested, much stronger evidence should be demanded before genome-wide embryo ranking is sold as routine reproductive care.
Polygenic Prediction Is Not Destiny
The promise of selecting for intelligence, height, complexion, athletic ability, or complex disease risk is more seductive than scientifically robust. These traits arise from many genes, their interactions with one another, and a vast range of environmental influences. Polygenic scores are population-level statistical estimates, not prophecies about an individual child.
Within one couple’s small group of IVF embryos, the genetic range available for selection is limited. Computer models suggesting gains of only a few centimetres in height or a few IQ points show that this is not a technology for manufacturing genius or athleticism. Two short parents cannot conjure tallness from genes they do not possess; two dark-skinned parents cannot reliably produce a fair-complexioned child merely by paying for genomic selection. What clinics are principally selling is not genetic mastery, but the illusion of control over biological chance.
There are further dangers, because selection for one desired outcome may carry uncertain implications for others. A higher score on one socially valued measure may correlate with different health or neurodevelopmental risks. It is ethically reckless to treat a complex human future as a single optimisation problem.
Singapore Must Draw the Line
Singapore already permits regulated IVF genetic testing for families at risk of transmitting known genetic diseases, including PGT-M and PGT-SR. That is a defensible medical use.
But due to technical uncertainty and ethical risk, the nation is also likely to prohibit or restrict PGT-WGS as a routine clinical service. That said, it should do more than refuse domestic approval. If local fertility providers are allowed to advertise, arrange, refer, or profit from overseas services that Singapore considers unsafe, inadequately validated, or ethically unacceptable, then regulation becomes a matter of geography rather than principle.
This is why Singapore should therefore prevent local clinics from facilitating overseas PGT-WGS for polygenic embryo ranking or non-medical trait selection. We should require independent genetic counselling, transparent disclosure of uncertainty and false-result risks, and impose strict limits on claims that any test can identify the ‘best’ embryo. Families facing a known risk of severe genetic disease deserve access to rigorous, compassionate, and clinically justified care. They do not deserve to be casualties in a genetic arms race.
PGT-WGS may generate an extraordinary amount of data. However, it cannot promise a designer child to order, and we should not permit commercial genomics to pretend otherwise.
Dr Alexis Heng Boon Chin is a Singaporean biomedical scientist and bioethics researcher. His work examines the ethical, legal and social implications of IVF, embryo genetic testing, reproductive genetics and emerging fertility technologies.
