What about the women? Ethical and policy aspects of egg supply for cloning research

Modelling human embryogenesis: embryo-like structures spark ethical and policy debate

BACKGROUND

Studying the human peri-implantation period remains hindered by the limited accessibility of the in vivo environment and scarcity of research material. As such, continuing efforts have been directed towards developing embryo-like structures (ELS) from pluripotent stem cells (PSCs) that recapitulate aspects of embryogenesis in vitro. While the creation of such models offers immense potential for studying fundamental processes in both pre- and early post-implantation development, it also proves ethically contentious due to wide-ranging views on the moral and legal reverence due to human embryos. Lack of clarity on how to qualify and regulate research with ELS thus presents a challenge in that it may either limit this new field of research without valid grounds or allow it to develop without policies that reflect justified ethical concerns.

OBJECTIVE AND RATIONALE

The aim of this article is to provide a comprehensive overview of the existing scientific approaches to generate ELS from mouse and human PSCs, as well as discuss future strategies towards innovation in the context of human development. Concurrently, we aim to set the agenda for the ethical and policy issues surrounding research on human ELS.

SEARCH METHODS

The PubMed database was used to search peer-reviewed articles and reviews using the following terms: 'stem cells', 'pluripotency', 'implantation', 'preimplantation', 'post-implantation', 'blastocyst', 'embryoid bodies', 'synthetic embryos', 'embryo models', 'self-assembly', 'human embryo-like structures', 'artificial embryos' in combination with other keywords related to the subject area. The PubMed and Web of Science databases were also used to systematically search publications on the ethics of ELS and human embryo research by using the aforementioned keywords in combination with 'ethics', 'law', 'regulation' and equivalent terms. All relevant publications until December 2019 were critically evaluated and discussed.

OUTCOMES

In vitro systems provide a promising way forward for uncovering early human development. Current platforms utilize PSCs in both two- and three-dimensional settings to mimic various early developmental stages, including epiblast, trophoblast and amniotic cavity formation, in addition to axis development and gastrulation. Nevertheless, much hinges on the term 'embryo-like'. Extension of traditional embryo frameworks to research with ELS reveals that (i) current embryo definitions require reconsideration, (ii) cellular convertibility challenges the attribution of moral standing on the basis of 'active potentiality' and (iii) meaningful application of embryo protective directives will require rethinking of the 14-day culture limit and moral weight attributed to (non-)viability. Many conceptual and normative (dis)similarities between ELS and embryos thus remain to be thoroughly elucidated.

WIDER IMPLICATIONS

Modelling embryogenesis holds vast potential for both human developmental biology and understanding various etiologies associated with infertility. To date, ELS have been shown to recapitulate several aspects of peri-implantation development, but critically, cannot develop into a fetus. Yet, concurrent to scientific innovation, considering the extent to which the use of ELS may raise moral concerns typical of human embryo research remains paramount. This will be crucial for harnessing the potential of ELS as a valuable research tool, whilst remaining within a robust moral and legal framework of professionally acceptable practices.

Ethical aspects of nuclear and mitochondrial DNA transfer

Somatic cell nuclear transfer (SCNT) (cloning), as a reproductive or therapeutic method, and mitochondrial DNA transfer, as a method to prevent the transmission of mitochondrial diseases, are analyzed in this paper from a bioethics perspective. The licit purpose of being able to treat certain diseases, as in the case of SCNT, cannot justify, in any case, resorting to illicit means such as the manipulation, selection, and elimination of human embryos in the blastocyst phase, by using cell lines obtained from them. Crossing this line paves the way (as utilitarian ethics advocates) to assuming any cost in scientific experimentation so long as satisfactory results are obtained. With mitochondrial replacement, either human embryos are directly manipulated (pronuclear transfer) or germline cells are manipulated (maternal spindle transfer); changes in these could be transmitted to the offspring.

LAY SUMMARY

This article analyzes somatic cell nuclear transfer (cloning) and mitochondrial DNA transfer techniques, in both reproductive and therapeutic applications, and preventive methods in the transmission of mitochondrial diseases, from a bioethical perspective. The manipulation, selection, and elimination of human embryos delimits the ethical acceptability of these promising techniques.

Ethical considerations in stem cell research on neurologic and orthopedic conditions

The range and gravity of ethical considerations in stem cell research are remarkable and, quite possibly, unprecedented. From the point of securing stem cells for implantation, through the translational and first-in-humans process, and then proceeding through clinical trials culminating in product or service line launch, the entire research trajectory is replete with risk, uncertainty, and problems overweighing foreseeable harms against hoped-for benefits. This article offers an overview of some of the most salient ethical challenges of stem cell research, including ones involving moral status, the intersection of research risks and informed consent processes, methodologic considerations in early phase 1 trials, the temptation to exaggerate the benefits of research discoveries, managing conflicts of interest, and the ethical obligation to conduct various monitoring practices throughout a trial, which could last years. The article will conclude with a glimpse into the future of these technologies wherein the need for ethical scrutiny will likely not diminish.

Implications of oocyte cryostorage for the practice of oocyte donation

As the efficiency of oocyte cryopreservation has increased rapidly in recent years, oocytes are currently being stored either in the course of IVF treatments or as a fertility preservation measure. These practices may have an impact on the number of available donor oocytes due to two different dynamics: first, a certain percentage of women for whom oocytes were cryopreserved will eventually not use their oocytes and may decide to donate them to others; secondly, especially in the practice of social freezing, women may opt to donate a portion of the retrieved oocytes in 'freeze-and-share' schemes in order to reduce the costs. In this article, we aim to sketch the ethical implications of such developments in general and the issue of payment to oocyte donors in particular.

Assessing the risk of ovarian hyperstimulation syndrome in egg donation: implications for human embryonic stem cell research

Stem cell research has important implications for medicine. The source of stem cells influences their therapeutic potential, with stem cells derived from early-stage embryos remaining the most versatile. Somatic cell nuclear transfer (SCNT), a source of embryonic stem cells, allows for understandings about disease development and, more importantly, the ability to yield embryonic stem cell lines that are genetically matched to the somatic cell donor. However, SCNT requires women to donate eggs, which involves injection of ovulation-inducing hormones and egg retrieval through laparoscopy or transvaginal needle aspiration. Risks from this procedure are fiercely debated, most notably risk of ovarian hyperstimulation syndrome (OHSS). This review examines risk of OHSS resulting from oocyte donation. We conclude that risk posed by OHSS in egg donation is not significant enough to warrant undue concern, and much of this can be eliminated when proper precautions are taken. This bears relevance to the future of stem cell research policymaking.

Distributive justice and infertility treatment in Canada

An exploration of distributive justice in Canadian infertility treatment requires the integration of ethical, clinical, and economic principles. In 1971, American philosopher John Rawls proposed a theoretical model for fair decision-making in which "rational" and "self-interested" citizens are behind a "veil of ignorance" with respect to both their own position and the position of other decision-makers. Rawls proposed that these self-interested decision-makers, fearing that they are among the least advantaged persons who could be affected by the decision, will agree only upon rules that encode equality of opportunity and that bestow the greatest benefit on the least advantaged citizens. Regarding health policy decision-making, Rawls' model is best illustrated by Canadian philosopher Warren Bourgeois in his panel of "volunteers." These rational and self-interested volunteers receive an amnestic drug that renders them unaware of their health, social, and financial position, but they know that they are representative of diverse spheres of citizens whose well-being will be affected by their decision. After describing fair decision-making, Bourgeois considers the lack of a distributive justice imperative in Canada's Assisted Human Reproduction Act, in contrast to legislation in European nations and Australia, summarizes the economic and clinical considerations that must be provided to the decision-makers behind the "veil of ignorance" for fair decisions to occur, and considers altruism in relation to equality of access. He concludes by noting that among countries with legislation governing assisted reproduction Canada is alone in having legislation that is void of distributive justice in providing access to clinically appropriate infertility care.