By Sinead Prince and Julian Savulescu
Imagine discovering that the child you gestated and have been raising for two years isn’t genetically yours – but someone else’s embryo was implanted by mistake. This isn’t science fiction; it happened in Victoria, Australia, in 2025. The case raises a profound question that courts, families, and society must grapple with: when medical errors create competing claims to parenthood, who should keep the child?
The Perfect Storm of Modern Reproduction
Two IVF mix-ups occurred in Victoria this year. In the first case, a woman gave birth to a stranger’s embryo, with the mistake discovered approximately two years after the birth, when the couple tried to transfer their remaining embryos to another clinic. In the second case, a woman gave birth to her own embryo, rather than her partner’s embryo as intended under the treatment plan. While the second case involves complex family dynamics, the first creates an unprecedented legal and ethical dilemma: one child, two sets of parents with legitimate interests in raising the child.
This isn’t the first time IVF mistakes have made headlines. From California to Singapore, embryo mix-ups have resulted in heartbreaking custody battles. However, unlike these other cases, no legal dispute has arisen, that is, the genetic parents haven’t yet made a legal claim to the child. We will, therefore, proactively and theoretically, but briefly, consider which parents have the strongest claim to the child.
The Genetic Claim: But for Us, This Child Wouldn’t Exist
The genetic parents have a compelling argument. They provided the DNA that created this unique person. Without their specific egg and sperm, collected at that precise moment, this exact child would never have existed. Our society places enormous weight on genetic relationships – they shape our identities, our sense of belonging, and our understanding of family. The genetic parents also desperately wanted this child. They endured the physical, emotional, and financial burden of IVF specifically to have a genetically related child.
But genetic relatedness alone doesn’t determine parenthood. Children are successfully raised by adoptive parents, step-parents, and other relatives. The foster care system, while prioritizing genetic parents when possible, recognizes that genetic connection doesn’t automatically equal fitness to parent.
The Gestational Claim: I Carried and Birthed This Child
The birth mother’s claim is equally powerful. She didn’t just provide a ‘vessel’ for someone else’s embryo – she contributed fundamentally to who this child became. During pregnancy, her body provided all the proteins, hormones, and nutrients that developed the fetus. Her immune system, stress levels, and overall health shaped the child’s development in ways that will last a lifetime.
Furthermore, recent research reveals that pregnancy involves much more than we previously understood. The birth mother’s DNA actually exchanges with the fetus, creating microchimerisms – she becomes, in a literal sense, part of the child’s biology. Her microbiome, her epigenetic influences, even her emotional state during pregnancy all contribute to the child’s biology and development.
Beyond biology, there’s the profound psychological and social bond formed during pregnancy, birth, and early care. The birth mother has already established what researchers call the maternal-infant attachment – a connection that benefits both mother and child’s wellbeing.
The Autonomy Problem
Perhaps most troubling is what happens if courts prioritize genetic claims. This effectively makes the birth mother an ‘unconsenting surrogate’: if women can be forced to give up children they gestated and birthed, we’re saying a woman’s body can be retroactively commandeered for another couple’s reproductive goals. Such a woman’s reproductive autonomy would be violated in a second way, namely, with the initial implantation of the wrong embryo, then parental autonomy violated with the removal of custody of the mother who’s so far been raising the child.
This raises uncomfortable questions about reproductive autonomy. If it’s justified to force a birth mother to relinquish a child she carried and intended to keep, what other reproductive decisions might be made for women rather than by them?
Beyond Simple Answers
The current legal approaches vary dramatically. Australian law presumes the birth mother is the legal parent, while US courts have sometimes prioritized genetic relationships. Neither approach seems fully satisfactory for these complex cases.
What’s needed is a more nuanced framework that considers multiple factors: the biological contributions of both parties, the social and emotional bonds already formed, the capacity and willingness of each party to parent, and crucially, what arrangement serves the child’s best interests.
This case also highlights the urgent need for better safeguards in IVF clinics. While mistakes happen, the profound human consequences demand the highest standards of care and verification procedures.
Moving Forward
No legal dispute has yet occurred, and arguably, it is much better for all parties if the dispute is resolved outside of court, namely, with voluntary agreement. But this case won’t be the last of its kind. As assisted reproduction becomes more common and complex, we need ethical frameworks that can handle these unprecedented situations fairly and compassionately.
Perhaps the most important lesson is that parenthood isn’t just about genetics or just about gestation – it’s about the complex interplay of biology, intention, care, and commitment. When medical errors create competing claims to a child, we need approaches that honor all these elements while keeping the child’s wellbeing at the center of our decisions. It’s a problem that deserves our most thoughtful consideration, not our simplest answers.
This post is based on research by Sinead Prince and Julian Savulescu that is intended for peer review. The authors used a personalized model of Claude, a generative AI large language model, to develop this post from an extended analysis intended for peer reviewed publication. The authors have reviewed and edited this piece.
Authors: Sinead Prince and Julian Savulescu
Affiliation: Centre for Biomedical Ethics, Yong Loo Lin School of Medicine, National University of Singapore
Competing Interests: None declared
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