We don’t get to choose our genes. But parents are now able to select their children’s genes in ways never possible before. The first baby born as a result of being singled out from a number of possible embryos with different probabilities of developing certain diseases is now a reality. The ethical concerns are many - eugenics have a nasty past and there are fears that already worsening inequality might become cemented in the ability of some parents to choose healthier, brighter children. But this technology will be what we make of it, and given its potential for good, we have a moral obligation to pursue it, argues Julian Savulescu.

Aurea Smigrodzki is still unaware of her significance in history. She is the first baby born on the basis of a polygenic score assigned to her future health, having been selected from 33 candidate embryos. In Aurea’s case, her parents were worried in particular about her risk of future breast cancer and heart disease: both had affected family members.

Testing for single genes, such as BRCA in the case of breast cancer, is already embedded in standard practice. In some countries up to one in ten babies is born via artificial reproduction technologies, including IVF. Up to 40 % of IVF babies undergo some pre-implantation testing for single-gene disorders. But many diseases are polygenic: they are influenced by multiple genes and the interaction between them. A polygenic score is a formula that assigns a risk level according to the probability of disease occurring with a set of genes.