Embryo rankings promise control, but the dark side of optimizing fertility is uncertainty

The drive for reproductive control

In a culture focused on self-improvement, efforts to optimize health have extended to reproduction. Journalist and author Kristen V. Brown says people seeking the healthiest possible baby may turn to technology in hopes of influencing the odds.

What embryo screening can assess

Preimplantation genetic testing for polygenic risk, or PGT-P, builds on genetic screening used with IVF. Brown said it estimates the likelihood of complex conditions, including heart disease and diabetes.

Unlike a condition linked to one gene, such as Huntington’s disease, heart disease involves hundreds of genes. It is also affected by environment and lifestyle, making predictions less certain.

Beyond medical conditions

Brown said companies are also marketing tests that claim to assess traits such as height and eye color, and in some cases IQ. Other promises involve Alzheimer’s disease and longevity.

The technology has moved beyond disease risk toward aesthetic concerns, Brown said. She questioned how intelligence can be defined, as well as how its genetic basis could be measured.

Growing interest, persistent concerns

Brown said only a small number of people are using the technology now, but more companies are entering the field and fertility doctors are showing greater support. She said many people in the fertility sector envision wider use because the idea is appealing, despite technical flaws.

Most mainstream medical societies oppose PGT-P, Brown said, as do many IVF doctors and people working in genetics. Embryo editing is illegal in the United States and most countries, though interest is growing as the technology improves. Brown said its safety cannot be confirmed until an edited embryo grows into an adult.