Event Review: Testing Embryos – How far should we go?

The first event in the Frontiers in the Ethics of Human Reproduction series from the Hastings Centre for Bioethics in New York – Testing Embryos: How Far Should We Go? – explores some of the most pressing questions in reproductive ethics, asking not only what embryo selection technologies can do, but what they should do.

Chaired by Dr Vardit Ravitsky, president and CEO of the Hastings Centre for Bioethics, the event opens with a concise overview of advances in IVF – from preimplantation genetic testing (PGT) for single-gene conditions in the 1990s, to whole-genome sequencing and preimplantation genetic testing for polygenic traits (PGT-P) today. As Dr Ravitsky explains, the debate has evolved into one about 'not just how we make babies, but what kind of babies we make.'

This sets the stage for a discussion looking to the future of embryo selection, focusing on whole-genome sequencing and PGT-P. Such topics were also explored during the 2025 PET annual conference 'What Does Genomics Mean for Fertility Treatment?' (see BioNews 1320).

I wrote about PGT-P while studying a module in bioethics at Newcastle University in 2024, drawing on Dr Ravitsky's work and countering Professor Julian Savulescu's idea of 'procreative beneficence' to argue that it should not be legalised in the UK. I am staunchly against the use of PGT-P for both trait and disease-based embryo selection and was happy to find points of both agreement and disagreement with all three panellists throughout the event.

The first panellist, Nat de Luca, an intensive care unit chaplain and master's student in bioethics at Harvard University, brings a personal dimension to the discussion. His presentation focuses on having had his own 'designer babies', a term he openly uses. He walks the audience through his major IVF decisions in an accessible way, including choosing his egg donors, surrogates, and who the genetic father would be.

Hearing a personal story is illuminating and unveils practical and ethical complexities that often receive less attention, such as the potential medical and travel restrictions imposed on surrogates, cross-border citizenship issues, and the expanded genetic screening offered to certain populations, for instance, Jewish communities at higher risk of Tay-Sachs disease. I felt there was a missed opportunity to further interrogate these points during the event.

Fertility specialist Professor Avner Hershlag from the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell in New York focuses on additional dilemmas that emerge in the clinic, including whether mosaic embryos and embryos affected by genetic conditions should be transferred during fertility treatment. He refers to Professor Michael Sandel's book 'The Case Against Perfection'when cautioning against PGT-P for trait selection, but expresses support for its use for certain diseases such as cancer. He also suggests that screening for conditions such as autism may one day be feasible. As an autistic person myself, this future makes me nervous. I am doubtful that polygenic screening will ever become good enough to give a robust prediction for autism; even if this were possible, however, it does not mean we should do it.

Professor Sandel's book is later referenced again by third panellist Dr Louise King, director of reproductive bioethics at the Harvard Medical School Centre for Bioethics, when emphasising the importance of prospective parents' and disabled people's perspectives. She reframes the debate as 'what would we lose' if we were to aim to screen for predisposition to all diseases, citing how disabled people have contributed to art, sport and science. I hesitate to justify the existence of disabled people in terms of the value they produce, however, preferring de Luca's assertion that our total human diversity is what 'makes life glorious'. Dr King also highlights the emotional, decisional and financial burden that increased choice puts on prospective parents, asking: 'is there ever such thing as too much choice?'

The last half of the event is a Q&A with the panellists that centres around three major themes: how embryos should be selected, the impact on disabled communities, and the legal ramifications of transferring embryos affected by genetic conditions. While de Luca stresses the right for prospective parents to transfer affected embryos, Dr Hershlag emphasises physician autonomy, sharing thathe would be unwilling to transfer an embryo with Huntington's disease but would attempt to support prospective parents by offering a free or discounted IVF cycle instead. Choosing which embryos to transfer can reflect assumptions about disability and quality of life. However, I disagree that we can predict a person's quality of life from an embryo's predicted disease status (BioNews 1325).

Dr King says that teaching this topic to bioethics students often 'puts her brain into pretzel mode', and that is certainly what this discussion does. By challenging the audience to consider multiple angles and perspectives, the event resists easy conclusions. For those who appreciate the format of PET online events, this series will feel familiar in structure but distinct in tone. I would recommend this event to anyone interested in the ethics of embryo selection, and I look forward to future installments in this series.