MEDIA outlets reported with enthusiasm last month on the birth and healthy development of what were widely termed “three-parent babies”. A team from the Fertility Centre, in Newcastle, had combined genetic material from mother, father, and donor, resulting in babies who were born free of inherited mitochondrial diseases.
Certainly, avoidance of the severe debilitating effects of these diseases is something to celebrate. The breakthrough raised moral, ethical, and social questions, however, on which the media reports were largely silent. It is in this wider context that Christian voices need to be heard.
But, first, how was the passage of genetic disease from mother to child interrupted? By far the majority of DNA is located within the nucleus of cells. A small but essential portion (less than one per cent) is located outside, however, in the mitochondria, where the cell’s energy is produced. Faulty mitochondrial DNA in a woman’s eggs can result in disease in her children. To counter this risk, the scientists substituted the mother’s mitochondria with those from another woman, the egg donor, during a modified IVF procedure.
In this process (technically termed pronuclear transfer), both the mother’s and donor’s eggs were fertilised with the father’s sperm. A few hours later, the sperm and egg nuclei were removed from the donor’s egg and replaced by those from the mother’s egg. The resulting modified embryo, comprising nuclear DNA from the mother and father plus healthy mitochondrial DNA from the donor, was implanted in the mother’s womb, resulting in pregnancy.
AS WITH any new technology, questions remain about long-term safety for the child. Less emphasised is the potential risk to the women undergoing treatment to produce large numbers of eggs. In terms of effectiveness, we must also wait and see. Faulty mitochondria can be carried over from the mother’s egg into the donor’s egg. The long-term risk of this “reversal process” is as yet unclear. But, beyond safety and effectiveness, what considerations should be raised?
First, there is the status of the human embryo. In total, 160 pairs of embryos, from mothers and donors, were used for mitochondrial transfer, destroying half of them. Forty of the remaining modified embryos were implanted in the wombs of 19 mothers, eventually resulting in eight babies; the remaining embryos were discarded or frozen. The longstanding question about when human life begins remains relevant, as does consideration of using the human embryos as a means to an end.
It is noteworthy in this context that the Newcastle team also have a licence for an alternative approach (termed maternal spindle transfer). With this technique, only the donor’s egg is fertilised, once her nuclear DNA has been removed and replaced with that from the mother. This technique significantly reduces but does not exclude embryo loss. As reproductive science progresses, and calls grow to permit research on embryos beyond the current 14-day limit, it is surely time for theologians and the Church to consider afresh the moral status of the human embryo (Comment, 31 January).
Second, we should ask where the technological advances around assisted reproduction might lead. Current UK regulations permit pre-implantation genetic screening of embryos for more than 1700 conditions; the production of egg and sperm from skin cells is being developed as to combat infertility; and gene-editing technology in embryos is being explored to correct disease or perceived human limitations.
A parent’s drive to have children genetically related to themselves is strong, and the pain of not being able to realise that desire should not be underestimated. Adoption is an option, but is not attractive to all. But it would be a mistake to normalise embryo manipulation to meet a rarely faced need, thereby opening the doors to wider interference in human procreation.
Furthermore, serious mitochondrial disease occurs in about 50 babies per year in England and Wales, and not all can be avoided by mitochondrial donation. The relative rarity of cases justifies calls for greater transparency in assessing the costs and public-health benefits, particularly given intense pressure on health services.
From a theological perspective, there is a need to discern where the technology of assisted reproduction goes beyond the restoration of fertility, diverging from the acceptance of a child as a blessing from God, born of an equal blend of a man and woman within the relationship of marriage. The introduction of a third person, be it via sperm or egg donation, may represent one of those divergences.
THIRD, what will be the effect on family relationships of introducing, for the first time in human history, a third person into the creation of a child? This question is critical, given that the family is a bedrock for nurturing children. In terms of self-identity and self-understanding, it is noteworthy how many children born to sperm donors have expressed a strong desire to learn about their biological fathers. In this regard, the remaining uncertainty as to the part that mitochondria and the contents of the donated egg might play in different human characteristics or disease risks is significant.
Currently, the Human Fertilisation and Embryology Authority states that, because of the quantitatively small amount of mitochondrial DNA, egg donors “will not have any legal rights or responsibilities over the child and they remain anonymous”.
But will that be enough for a child who learns that they are a blend not of two but three individuals? For girls, they will face the fact their children, grandchildren, and so forth will inherit the mitochondrial DNA from the woman who donated her egg. Will the genetic presence of a third person impinge on the precious relationship between a child and its parents, or, indeed, between the parents themselves? Understanding the effects on these relationships is equally as relevant as understanding the safety and effectiveness of these technologies.
THE opportunities and challenges of assisted reproductive technologies are not going away. Infertility is rising globally: about one in six adults is affected in their lifetime. Consequently, an increasing number of families are having to make choices about the growing range of available interventions. These technologies raise complex questions about procreation and the nature and responsibilities of parenthood.
Specific examples include the status of the human embryo during IVF, genetic testing of embryos and foetuses to avoid having children with disability or to select “desirable” characteristics, and the use of donor sperm or eggs. Increasingly, church leaders will need to be aware of these topics and provide support. This implies the availability of relevant education and training, combining scientific, theological, and pastoral perspectives.
In the wider context, far greater debate is needed about the future applications of genetic and reproductive technologies. The Christian faith has much to offer, but, surely, Christians need to amplify its voice. While doing so, they can affirm the immense and equal value of every individual, made in the image of God; aspire to protect the weak and vulnerable; and strive to practise love of neighbour as self. These core beliefs and values should inform personal decision-making, besides driving a fresh public engagement in areas of science which will surely influence the future of humanity.
Dr Chris Wild is author of Unravelling DNA: Applying Christian values to a genetic age (GBJ Books, 2025).
