Would you rather have a child with (1) an estimated twenty-five percent higher lifetime risk of cancer, (2) a predicted threefold risk of Alzheimer’s disease, or (3) a three-point bump in IQ but an added risk of heart disease? How would you decide, and how much would you trust the numbers?
These are real questions raised by polygenic embryo screening (PES), one of the newest frontiers in reproductive technology. Since the 1990s, prospective parents undergoing in vitro fertilization (IVF) have been able to screen embryos for rare conditions caused by mutations in single genes, such as cystic fibrosis and Tay-Sachs disease. Polygenic embryo screening is different. Instead of checking for a single mutation, PES screens and ranks embryos based on their likelihood of developing conditions like breast cancer, diabetes, and dementia—conditions influenced by many genes and environmental factors. Although PES is marketed primarily as a tool to reduce disease risk, the technology could also be used to select for traits such as height or cognitive ability. As a result, PES occupies a contentious space between the promise of prevention and the uncertainties of science and ethics.
Such concerns have not deterred companies eager to market PES. Orchid, a California-based company, sequences more than ninety-nine percent of an embryo’s genome and uses PES to screen for dozens of common diseases. The front page of its website urges parents to “have healthy babies,” framing the service as a way to extend parental responsibility into the earliest stages of life. By providing risk profiles for conditions such as Alzheimer’s disease, diabetes, and schizophrenia, Orchid positions embryo selection as a proactive step to reduce suffering and secure healthier futures.
Critics counter that this framing overstates what the science can deliver. PES relies on correlations from large genetic databases, and those correlations may not be equally reliable for each individual embryo. A child with a “low-risk” score may still develop a serious illness, while one flagged as “high-risk” may remain completely healthy. PAnd predictive accuracy is limited by biases in the underlying data: most biobanks used to train the models consist largely of individuals of European ancestry. For families from non-European backgrounds, this reduces accuracy, leaving parents to make high-stakes decisions based on numbers that may not reflect reality.
Beyond scientific uncertainty, PES raises significant ethical concerns. One is equity. A single round of IVF already costs tens of thousands of dollars, and Orchid’s screening adds another $2,500 per embryo. This price tag risks widening inequalities in access to reproductive options.
Another concern is the potential slippery slope from prevention to enhancement. While companies like Orchid have limited their public services to disease-related screening, others, such as Nucleus Genomics and Heliospect, already advertise predictions for traits like intelligence. These claims rest on shaky science: traits like intelligence depend on the interaction of many genes and environmental factors, and because these influences are not fully understood, DNA-based predictions remain highly uncertain. Still, the very act of marketing these services pushes PES toward the logic of “designer babies,” raising uncomfortable echoes of eugenics—the early twentieth-century movement that ostensibly sought to improve society by promoting the reproduction of certain traits while preventing that of others. What began as an effort to “have healthy babies” could evolve into a means of attempting to engineer “better” babies, suggesting certain lives are more worth bringing into the world than others. Such a shift risks reinforcing stereotypes about health and ability, stigmatizing people with illness or disability, and normalizing the idea that children should meet certain genetic standards before they are even born.
As our knowledge of human genetics advances, the predictive capabilities of polygenic embryo screening will only continue to expand. Currently, there are no regulations in the United States governing what traits can be screened for or how reliable the results must be, leaving decisions about the limits of this technology almost entirely in the hands of private companies. Until those boundaries are drawn, we are left to question not only what science can do, but what it should do.