The paper by Savulescu et al is timely and the concepts illuminated deserve further reflection.1 Reproductive tissue which includes sperm, oocytes and embryos are commonly treated differently to other human tissue, even when the reproductive potential of these has no possibility of being realised. This unnecessary exceptionalism hampers research in human reproduction, disadvantaging patients and delaying life-changing treatments from being incorporated into clinical practice. In jurisdictions where embryo creation is permitted for clinical purposes, such as in vitro fertilisation (IVF), supernumerary embryos are routinely discarded once they are no longer required to attempt pregnancy. We contend that research on such embryos, which will never realise their reproductive potential, is not substantially different to any other human tissue research and should not require any additional ethical or regulatory oversight. The only individuals who can possibly be harmed by such research are the tissue providers and their interests, including confidentiality and informed consent provision, should be protected. This protection once again is no different in its scope to any other type of research involving human cells and tissues. Most Western societies have moved away from the concept that ‘every sperm is sacred’ and it is time that the regulators and scientific community aligned with the prevailing communal norms and stop treating gametes and embryos as somehow holding higher moral value, compared with other human cell/tissue lines, provided that there is no intention to attempt a pregnancy with such cells. This is what Savulescu et al designate non-future person research. The interests of cell providers must be respected and protected, but it is time to acknowledge that reproductive cells destined for destruction can be used to advance scientific knowledge, have minimal moral value and do not have any interests in and of themselves, beyond the interests of the cell providers.

An embryo that is destined to be transferred into a uterus with the intention of achieving pregnancy has a significantly higher moral value arising from its inherent potential to become a human being. Therefore, any research involving the manipulation of such embryos has the potential of altering it. This not only creates risks for a future human being but may also adversely affect the future parents. This is what Savulescu et al designate future person embryo research, which requires additional ethical scrutiny. However, one must be careful not to over-reach in this regards. Most embryology research in the IVF setting aims at improving clinical outcomes, such as time to pregnancy, clinical pregnancy rates and life birth rates. A small minority of studies follow-up the children who were born as the result of IVF but follow-up periods are limited to a couple of years at most, usually for logistical reasons. Therefore, when an ethics committee is confronted with a research project that involves manipulation of embryos that is unlikely to alter their genetic makeup, the pragmatic approach should be to consider the impact on clinical outcomes of IVF only, rather than largely unknowable effects that such manipulation could have on potential human beings born from these embryos. In a way future person embryo research is somewhat misleadingly named, since the effects of embryo manipulation, short of direct genetic alterations, will not be known for many decades. It is important to remember that the technique of IVF itself was never subjected to rigorous research before widespread implementation and long-term follow-up of people conceived via IVF is only now becoming available and is largely reassuring.2

This brings us to the type of research which we believe constitutes a different category or designation, which requires less ethical scrutiny: embryo selection without modification. Such research does not alter embryos in any way and its common aim is to shorten time to pregnancy. It involves embryo selection or the order in which available embryos are to be transferred. It is generally accepted that ‘good’-quality embryos are more likely to result in a viable pregnancy compared with poor-quality ones. A number of grading systems are in use, the most common being the Gardner classification.3 It is based on morphological description of an embryo on day 5 of its development, which correlates with its chance of resulting in a viable pregnancy. The current practice is to transfer the best embryo first, as this results in the shortest interval to pregnancy. Various other criteria have been proposed for embryo selection based on embryos’ developmental milestones, metabolic profiling, genetic constitution of the culture fluid, just to name a few.4 Artificial intelligence (AI) systems are being developed, which use large data sets of patients’ characteristics and diverse embryological development information to select embryos with the highest potential to produce a viable pregnancy. Implementation of such selection schemes requires a randomised trial comparing its outcomes to the current practice of using the Gardener classification for embryo selection. One must be cognizant of the fact the Gardener classification’s aim is to select an embryo that has the highest chance of producing a pregnancy. This is also true for all other embryo selection methods, including AI-based systems. It is unknown whether it produces the healthiest or the happiest person possible. These questions cannot be answered without a life-long follow-up of the resultant human beings. The outcomes of such trials are typically limited in their scope to viable pregnancy rates only. The deeper philosophical dilemma of one person existing, as opposed to another, should not be considered in the ethical evaluation of such trials. We agree with Savulescu et al that such a trial, assessing the order of embryos being transferred, could potentially harm the gamete providers should the time to pregnancy lengthen, but such research cannot be considered future person embryo research, since embryos themselves are not altered in any way, rather the order of implantation is modified. A note of caution is perhaps required: while embryo selection to achieve a desired outcome faster, that is, viable pregnancy, is a worthy goal, one must not base the decision on the viability of embryos on untested novel embryo assessment tools. There is at least one known instance of possibly viable embryos being discarded, based on flawed assessment of their reproductive potential, using one of the novel genetic techniques.5 When unproven technology is used, rigorous scientific evaluation is essential, since a discarded embryo has zero chance of producing a baby, and, therefore, the decision to discard an embryo must be very carefully considered. Even poor-quality embryos assessed to be genetically abnormal have been reported to produce a healthy child.6 In some instances, such an embryo may be the only one that would give prospective parents a chance of genetically related progeny. Therefore, any decision to discard embryos as part of a research protocol must be subjected to highest levels of ethical and scientific scrutiny, while if only the order of transfer is under scrutiny, less oversight is justified.

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