Recent biotechnology breakthroughs suggest that functional human gametes could soon be created in vitro. While the ethical debate on the uses of in vitro generated gametes (IVG) was originally constrained by the fact that they could be derived only from embryonic stem cell lines(1,2), the advent of induced Pluripotent Stem Cells (hiPSC)(3) creates the possibility that somatic cells may be used to generate gametes. This means that in the future it might be possible to generate human sperm and oocytes from male cells and oocytes from female cells (so far it has not been possible to derive sperm from female cells).
Among the different applications that have been explored(1,2), like the creation of embryos for genetic research and what has been called “in vitro eugenics”(4), we think that the most dramatic application of IVG will be in the field of human reproduction. In a recent article in the Journal of Medical Ethics, Robert Sparrow(4) rightly notices that IVG could allow: post-puberty males who are unable to produce viable sperm, women who have undergone premature menopause, and those who have lost their gonads due to injury or had them removed in the course of cancer treatment to have genetically related kin. To this list we add (and explore in our paper) a fourth category that has been overlooked until now, namely that IVG would allow the reparation of some of the harms done to people by means of biological involuntary sterilization.
Also, the feature of IVG that that we think could revolutionize human reproduction will be the expansion of reproductive options to beings that are not currently expected to be fertile and who can be grouped into six categories, these are: i) cell lines, ii) embryos, foetuses and children, iii) deceased individuals, iv) postmenopausal women, v) single individuals, and vi) same-sex couples.
The use of IVG by the last group of this sixth category is where we see the greatest scope in practice and the more far-reaching transforming implications. The fact that same-sex couples will have the option to have children as closely genetically related to them as those produced by different sex couples, through sexual reproduction, is not going to pass unnoticed.
Beyond same-sex genetic parenting the most paradigm-shifting application of IVG could be a radical expansion of reproductive autonomy that allowed more than two persons to engage simultaneously in genetic parenting. 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. But this entails only a minimal mixing of genetic material and indeed precisely this feature has been invoked to dispel fears of 3-way genetic parenting. On the other hand IVG could permit instead a much more substantial sharing of genetic kinship, through what is in essence a generational shortcut (for an argument about how polygamy can be egalitarian see Is Polygamy Inherently Unequal? by Gregg Strauss ).
Imagine that four people in a relationship want to parent a child while being all genetically related to her. IVG would enable this scenario by means of a reiterative production of embryos and gametes that would allow generational shortcuts. IVG could allow the genome to be distributed and shared equally, bending the temporal necessity of genetic generations to the social and cultural preferences of our times. Indeed, by taming genetic kinship for parenting preferences, IVG may well be regarded as the most salient example in the co-production of biotechnological pluralism, whereby normative commitments recruit biotechnological ingenuity to turn possible life styles, into actual living options. For a more in depth exploration of these issues you can read the paper here Multiplex parenting: IVG and the generations to come.
By César Palacios-González (@CPalaciosG), John Harris and Giuseppe Testa
1. Testa G, Harris J. Ethical Aspects of ES Cell-Derived Gametes. Science. 2004 Sep 17;305(5691):1719–1719.
2. Testa G, Harris J. Ethics and synthetic gametes. Bioethics. 2005 Apr;19(2):146–66.
3. Takahashi K, Yamanaka S. Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors. Cell. 2006 Aug 25;126(4):663–76.
4. Sparrow R. In vitro eugenics. J Med Ethics. 2013 Apr 4;medethics–2012–101200.
5. Palacios-González C, Harris J, Testa G. Multiplex parenting: IVG and the generations to come. J Med Ethics. 2014 Mar 7;medethics–2013–101810.