Inside the new quest to design the ‘ideal’ baby

For more than three decades, doctors have offered genetic tests to families using in vitro fertilisation. These tests once focused on clear medical conditions such as cystic fibrosis or Huntington's disease. Parents sought reassurance that their child would not inherit a known disorder. The goal was simple and grounded in clinical evidence.

But a new market is now growing around a more ambitious idea.

It suggests that advanced genetic sequencing can reveal far more than medical risk. According to a recent cover story by MIT Technology Review, several companies claim they can read an embryo's entire instruction manual and make predictions about complex traits.

These include intelligence, personality, behaviour, and even aspects of appearance. Their message is that parents may choose the most promising future for their unborn child.

This message has drawn strong demand from a small but influential group. Among them are prominent figures in Silicon Valley, including well-known technology entrepreneurs. They are willing to pay high fees for a process that promises to optimise the potential of their children. Some see it as the next frontier of human progress. Others view it as a dangerous step toward a very old idea.

The science behind these claims is known as polygenic testing, or PGT-P. It studies hundreds or thousands of genetic variants at once. The results are combined into a polygenic risk score. The score aims to show how likely an embryo is to develop a condition or exhibit a particular trait. The approach is built on huge biobanks of genetic data and on statistical models that search for patterns in this information.

Yet the confidence of companies selling these services is not shared by many experts. Researchers have pointed to several limitations. Much of the available genetic data comes from people of Western European ancestry, which reduces accuracy for others.

Some critics say that the push to select embryos for traits revives the logic of eugenics. This history stretches back to Francis Galton in the 19th century and includes some of the darkest policies of the 20th. Modern supporters of PGT-P reject this comparison, saying that voluntary choice is different from coercion. But the shadow of the past is difficult to ignore.

Environmental influences, upbringing, and chance also play large roles in human development. When the sample size is as small as a single set of sibling embryos, predictions weaken further. In short, the science is not precise enough to match the promises made in marketing brochures.

Professional medical bodies remain cautious as well. The American College of Medical Genetics and Genomics has warned that the practice has moved ahead too quickly.

Similar concerns have come from European researchers. They note that there is little clinical research to show how well these predictions work in real embryos. They also argue that parents must be fully aware of the limits of the technology.

These scientific questions sit alongside deeper ethical debates. Some critics say that the push to select embryos for traits revives the logic of eugenics. This history stretches back to Francis Galton in the 19th century and includes some of the darkest policies of the 20th. Modern supporters of PGT-P reject this comparison, saying that voluntary choice is different from coercion. But the shadow of the past is difficult to ignore.

The conversation has grown even more charged as public figures on the political right discuss genetic determinism. Claims about intelligence, crime, or behaviour being fixed in DNA have spread widely on social media. Some accounts, amplified by powerful technology leaders, have used these ideas to argue for social or political positions. Researchers worry that weak science is now feeding strong ideology.

Meanwhile, the companies behind these tests are expanding. Genomic Prediction and Orchid were early players. Newer entrants such as Nucleus Genomics and Herasight have taken bolder steps, especially around intelligence. Their websites list thousands of traits and diseases. Prices range from a few thousand dollars to tens of thousands. Some companies even offer full IVF packages that promise a seamless path from data to baby.

At the same time, many IVF patients are uneasy — they fear that public attention on polygenic testing distorts their reasons for seeking treatment. Most want healthy pregnancies, not designer children. They also worry that the debate paints them as consumers shopping for ideal traits, rather than parents navigating a difficult medical journey.

For now, the promises remain ahead of the evidence. There are no long-term studies following children selected using these scores. There is no way to know how much influence these predictions truly have.

What remains is a sense of uncertainty and a widening gap between scientific caution and commercial ambition. The question facing society is not only what science can reveal, but what future we wish to choose.