1 Stem cell derived gametes and uterus transplants: hurray for the end of third party reproduction! Or not? Heidi Mertes Introduction Although third party reproduction has become increasingly accepted, it remains a last resort and a suboptimal option for most people, which is often only taken into consideration when reproduction with one’s own gametes or own womb has proven to be impossible 1 . The paradigmatic cases for people who cannot become genetic or gestational parents/mothers are people who lack (functional) gametes and women who lack a uterus, either from birth or due to disease. In an effort to make genetic and gestational parenthood possible even for these two groups, research is being conducted aimed at deriving gametes from stem cells matched to the patient and clinical trials are ongoing for uterus transplantation. Both are examples of what Donna Dickenson has called ‘Me Medicine’, medical interventions focusing on individual interests, rather than on the common good 2 . However, are these also worrisome examples of Me Medicine? And is an alternative, We Medicine approach possible? The science Stem cell derived gametes In order to produce gametes in vitro containing the genetic material of the patient, several steps are needed, which are all technically difficult and at present experimental. First, a stem cell line needs to be created matching the patient’s genome. This can currently be done in two ways. The first technique – called somatic cell nuclear transfer (SCNT) or ‘therapeutic cloning’ – involves the transfer of the cell nucleus of a somatic cell of the patient (for example a skin cell) into an enucleated egg cell. The egg cell will then erase the epigenetic marks on the nuclear DNA and on activation an embryo can be grown which is genetically identical to the patient (not taking the mitochondrial DNA into consideration). When this embryo reaches the blastocyst stage (after 5 days), the inner cell mass can be extracted and cultured, resulting in an embryonic stem cell line. The second technique is direct reprogramming, resulting in induced pluripotent stem cells (iPS cells). In this scenario, somatic cells are reverted to their embryonic state by adding a small number of specific factors, a technique for which the Nobel prize in physiology or medicine was awarded to Sir John B. Gurdon and Shinya Yamanaka in 2012. Once a stem cell line has been established containing the DNA of the patient, gametes (ideally sperm or egg cells, or precursors of those cells) need to be derived from those stem cells. In the mouse model, significant progress has been made in the last decade, resulting in the 1 Elia Wyverkens, Veerle Provoost, An Ravelingien et al, ‘The meaning of the sperm donor for heterosexual couples: confirming the position of the father’ (2015) 56 Family Process 203-216. 2 Donna Dickenson, Me Medicine vs. We Medicine: Reclaiming Biotechnology for the Common Good. (New York: Columbia University Press, 2013).