Robert Sparrow highlights the possibility that future success in deriving gametes from human pluripotent stem cells could forge a path to the creation of multiple generations of embryos in vitro, ultimately allowing for selective breeding of embryos as a means of producing humans with ‘enhanced’ genomes.1 Sparrow refers to this iterative use of gametogenesis as ‘in vitro eugenics’, and argues that proponents of enhancements have a ‘strong moral reason’ to embrace it. He also speculates that current barriers to research on this technology will be lifted to permit the advances in vitro gametogenesis research promises in addressing infertility. One might thus expect the possibility of in vitro eugenics to stoke the hopes and fears of those with competing views about human enhancement. However, as I argue below, such reactions would be misplaced in the context of this technology both because we should anticipate very little, if any, demand for it as a means of creating children, and because, contra Sparrow, even proponents of enhancements can plausibly deny that there exist strong moral grounds for employing this technology. These considerations will further suggest that some substantial ethical and regulatory barriers to research on in vitro eugenics are likely to remain.

Let us suppose researchers …