[M]ost of you reading this blog know all about three-way parenting where a second female contributes mitochondrial DNA to a fertilized egg and becomes in essence a ‘second mother’. Well, hold on to your PCR machines, kiddoes, there’s a new gamete in town. IVG is the process us turning adult cells (such as skin cells) into pluripotent cells (essentially stem cells) that are then converted into gametes (ova and sperm). That’s the ‘G’ in IVG, ‘gametogenesis’. With this new science comes a wealth of potential dangerous possibilities, including but not limited to ‘multiplex parenting’ (more than three). Here’s what the authors of a recent argument paper published at the online Journal of Medical Ethics propose:
Currently, for three or more individuals who wanted to share genetic parenting, the only theoretical option would be through replacement of mitochondrial DNA (mtDNA), creating an embryo inheriting the nuclear genome from a man and a woman and the mtDNA from a second woman. In the UK this approach has been recommended by the Human Fertilisation and Embryology Authority as ethically sound for the prevention of devastating diseases due to mtDNA mutations and entails only a minimal mixing of genetic material. Indeed, precisely this feature has been invoked to dispel fears of three-way genetic parenting.44 ,45 IVG could permit instead a much more substantive sharing of genetic kinship, through what is in essence a generational shortcut. Imagine that four people in a relationship want to parent a child while being all genetically related to her. IVG would enable the following scenario: first, two embryos would be generated from either couple through IVF with either naturally or in vitro generated gametes. hESC lines would be then established from both embryos and differentiated into IVG to be used in a second round of IVF. The resulting embryo would be genetically related to all four prospective parents, who would technically be the child’s genetic grandparents. In light of the developments we have anticipated above, several variations are possible over this scheme, including trios and same-sex partnerships, though in the case of trios the extent of inbreeding would need to be dealt with on a par with that outlined above for self-reproducers.
Given the changing landscape of what constitutes a family, we shouldn’t be surprised at the notion of multiplex parenting. Lawyers might want to start boning up on arguments for the inevitable breakup of these new collective parent groups. Shared custody and finances are tricky enough when two parents are involved; now imagine that same scenario with four or more.