8/10/25
Can a baby have three parents? Early this month, eight children were successfully born in the UK through Mitochondrial Replacement Therapy (MRT), marking a significant milestone in reproductive medicine. This technology, often dubbed “three-parent IVF,” allows women with mitochondrial diseases to have healthy children without passing on mitochondrial defects.
The procedure involves transferring the nuclear DNA from a mother’s egg into a donor egg containing healthy mitochondria, which is then fertilized with the father’s sperm. Though the technique uses genetic material from three individuals, the donor’s 0.1% genetic contribution doesn’t influence inherited traits like appearance or personality. Thus, MRT is generally not considered a “gene-editing” treatment like CRISPR or other targeted gene-editing technologies.
A particularly moving case emerged from the Newcastle clinic this month, where a mother shares her excitement upon successfully giving birth using MRT. “As parents, all we ever wanted was to give our child a healthy start in life,” she shares, “mitochondrial donation IVF made that possible. After years of uncertainty, this treatment gave us hope — and then it gave us a baby.”
However, these scientific advances have sparked intense debate within medical and ethical communities. Dr. Francois Baylis from Dalhousie University in Canada expresses her concern over MRT’s implications: “There are risks to the women who are going to be receiving the embryo, and there are risks to the women who are the donors of the eggs that will be providing the mitochondria.”
Such safety concerns have led the United States to maintain a strict ban on MRT procedures, enforced through federal funding restrictions and regulatory barriers. The FDA has also not approved clinical trials, citing worries about the long-term safety of children born via MRT and the potential for heritable effects. Supporters of the ban also emphasize that legalizing mitochondrial replacement could lead to wider and potentially inappropriate genetic modifications in human reproduction.
Religions worldwide also have different opinions on MRT. While Catholic bishops in England and Wales, led by Bishop John Sherrington, oppose mitochondrial donation treatment due to the destruction of human life, Jewish bioethicists are more supportive under the ethical principles of beneficence and social responsibility. Meanwhile, the Church of England reserved its opinions until “there has been further scientific study and informed debate into the ethics, safety and efficacy of MRT.“
Family dynamics in MRT cases have also attracted attention from social scientists. Researchers have explored the new online family dynamics arising from MRT, observing how these families value relationships beyond traditional genetic links despite multiple contributors. A 2021 Canadian social research study also explores the attitudes of families affected by mitochondrial diseases and discovers a strong desire for reproductive autonomy and biological kinship, with many prioritizing MRT over alternatives like adoption to have healthy, biologically related children.
Currently, only the UK’s Newcastle Fertility Centre is licensed to perform the procedure, while countries such as the United States and Canada have restricted MRT usage. This difference creates “fertility tourism,” where patients travel abroad to seek less strictly governed fertility treatments, leading to regulatory and safety concerns. Several countries, including Australia and Japan, are developing regulatory frameworks for MRT, but progress is slow, and the procedure is not yet fully legalized.
However, the UK’s MRT success will provide crucial data for other countries considering legalization. Meanwhile, support groups for families affected by mitochondrial diseases also offer resources for parents navigating these uncharted waters. As one parent in such a group noted, “[UMDF Support Ambassador] has connected me with other families, which has been invaluable during the ups and downs of my daughter’s diagnosis process.”
As this technology reshapes society’s understanding of biological parenthood, the UK’s MRT success offers hope to families affected by mitochondrial disease. Yet the path forward requires careful consideration of medical outcomes and the complex intersection of ethical, psychological, and social implications that come with pushing the boundaries of human reproduction.