In a culture obsessed with optimisation—from fitness trackers that count steps to diets that promise peak performance—reproductive choices are becoming the newest frontier. Expectant parents are now looking beyond traditional prenatal care, turning to sophisticated laboratory techniques that promise a measure of control over a child’s genetic endowment.
Journalist Kristen V. Brown author of the upcoming The Immortal Womb explains that this drive stems from a simple desire: “I think that what we’re seeing right now is that people will do anything they can to have the healthiest baby possible.” Her conversation on the Explain It to Me podcast highlighted how couples are hunting for ways to tilt the odds in their favour, a sentiment captured in the question, “How do I skew the odds in my favour?.” The technology at the centre of this quest is preimplantation genetic testing for polygenic risk (PGT-P).
What PGT-P actually does
PGT-P builds on the standard preimplantation genetic testing that IVF clinics already perform to detect single-gene disorders such as Down syndrome. Unlike those binary screens, PGT-P evaluates dozens—or even hundreds—of genetic markers that together influence the likelihood of complex conditions like heart disease, type-2 diabetes, or Alzheimer’s. As Brown notes, the intent is to “let people have the healthiest baby.” The process begins with embryos created in the lab; a few cells are biopsied, DNA is extracted, and sophisticated algorithms assign a risk score for each polygenic trait.
Because traits such as height or eye colour are governed by many genes interacting with environment, the predictions are probabilistic rather than deterministic. For example, while a particular set of variants might raise the statistical chance of being taller, nutrition, exercise, and chance still play large roles. The same uncertainty applies to disease risk, making the technology a blend of science and educated guesswork.
How the market is framing the technology
Several fertility companies have begun advertising PGT-P as a way to “design” a child. Their marketing materials suggest that parents can select embryos not only for reduced disease risk but also for aesthetic attributes—height, eye colour, even purported intelligence scores. The idea of a “Gattaca stack” a term borrowed from the sci-fi film, encapsulates this vision: combine an endless supply of embryos generated through in-vitro gametogenesis (turning skin cells into eggs and sperm), run them through PGT-P, and then nurture the chosen ones in an artificial womb.
In practice, the uptake remains modest. Brown estimates the current user base is “a very small number of people at this point,” yet she observes a growing chorus of fertility clinics offering the service. Mainstream medical societies, however, remain skeptical, with many IVF specialists questioning the clinical value of polygenic screening for embryos or adults alike.
Ethical cross-roads and the shadow of eugenics
The conversation soon drifts from technical capability to moral philosophy. Critics liken large-scale embryo selection to eugenics arguing that preferring certain genetic profiles—whether to avoid disability or to enhance perceived desirable traits— echoes historic attempts to engineer a “perfect” population. Brown points out that even today, prenatal screening for Down syndrome is sometimes framed as a form of eugenics, despite the condition being compatible with a full, rewarding life.
Legal constraints add another layer. Direct embryo editing (altering DNA after fertilisation) is prohibited in the United States and most other nations, primarily because safety cannot be guaranteed until the edited individual reaches adulthood. The current regulatory climate permits only selection, not modification. Yet interest is rising, especially for couples who are carriers of serious monogenic diseases like Huntington’s, where selecting an unaffected embryo can dramatically improve reproductive odds.
Beyond disease, the push toward aesthetic traits raises profound questions about parental responsibility and the nature of consent. As Brown reflects, “becoming a parent is an exercise in giving up control,” and the more variables introduced, the further we drift from the natural unpredictability of human birth.
If listeners want to explore these issues in depth, the full interview is available on Apple PodcastsSpotify or any platform that hosts the Explain It to Me show. For questions, email askvox@ or call 1-800-618-8545.
