In in vitro eugenics (IVE), I outlined a theoretical use of a technology of artificial gametogenesis, wherein repeated iterations of the derivation of gametes from embryonic stem cells, followed by the fusion of gametes to create new embryos, from which new stem cells could be derived, would allow researchers to create multiple generations of human embryos in the laboratory and also to produce enhanced human beings with desired traits.1 As a number of commentators observed, my purpose in publishing this paper was to provoke ethical discussion of a largely unremarked upon technological possibility and surrounding issues. Even if this was, as Murphy2 observes archly, to aim low , discussion of IVE is valuable for three reasons. First, it may render us better prepared should IVE become practical. I noted of my original discussion that it was speculative and several of the respondents suggest that IVE is even less likely to come about than I allowed there. Nevertheless, second, discussion of IVE is valuable for what it reveals about the ethics of new reproductive technologies (NRTs) more generally and, third, about the ethics of genetic human enhancement in particular. The responses to my paper demonstrate this nicely by (a) illustrating the selective way in which arguments about risk are mobilised in debates about NRTs and (b) highlighting the tension between any obligation of procreative beneficence and a concern for genetic relatedness. Even if IVE should never be pursued, then, discussion of this possibility may help us better understand the ethics of other NRTs and means of genetic human enhancement.