Polygenic embryo screening: The tension between choice and acceptance

Polygenic embryo screening (PES), also known as preimplantation genetic testing for polygenic conditions and traits (PGT-P), is a hot topic right now. The recent PET (Progress Educational Trust) annual conference had a session exclusively devoted to discussion of the technology (see BioNews 1320), and MIT Technology Review has named it as one of the ten breakthrough technologies of 2026.

In a qualitative study of US-based reproductive endocrinology and infertility specialists and recent or current IVF patients, a gap exists between the two stakeholders' perspectives of PES. Many patients were interested in PES or conditionally so, depending on whether it was free or affordable, or contingent on their specific family histories. Even patients who were not interested in using PES were respectful of others' choice to use it.

In contrast, most clinicians were either unwilling to discuss or offer PES, or to do so only under certain circumstances – such as if the patient inquired specifically about it or as part of a research protocol. Clinicians' reservations were largely due to concerns about the limitations of PES – as highlighted by Dr Emma Meaburn (see BioNews 1302) – with respect to its clinical validity and clinical utility, including its transferability to individuals of non-European descent.

However, there is another important limitation that is shared by other prenatal and preimplantation genetic tests: these tests cannot determine condition severity. Though there is no consensus over what severity entails, its subjectivity relies on perceptions of and the interplay between symptoms of and associations with conditions.

Considering the uncertainty of severity for conditions with variable expression, (prospective) parents desiring the best for their offspring may find reproductive decisions challenging when faced with these tests. Therefore, they may focus on 'worst' case scenarios (the most severe manifestations of the condition), as indicated by a study of individuals who underwent reproductive carrier screening and received an increased-chance result.

However, it's important to keep in mind that polygenic conditions are multifactorial, influenced by the interaction of many genes as well as environmental and lifestyle factors, and thus many are manageable or treatable. They're common conditions – such as autism, various cancers, depression, and diabetes – that many people survive, live with, and even flourish with.

As with other biotechnologies that enable selective reproduction (such as prenatal testing and other forms of PGT), PES brings about a tension for (prospective) parents between choice and acceptance. Choice may be framed in terms of the principle of procreative beneficence, which endorses the selection of embryos that are most likely to have the best life, based on available genetic information.

Demonstrating this principle, IVF patients and clinicians in the aforementioned study expected and thought it was natural for parents to select embryos with the lowest genetic chances for developing health conditions or the highest genetic chances for developing desirable non-medical traits. Some characterised such embryo selection as what a responsible parent does to protect a child from difficulty, struggle, or suffering. They also discussed how such embryo selection is done in the best interest of the future child.

Additionally, several patients and clinicians noted desires for 'the best' or a child's success and societal contribution. Furthermore, as Professor Angus Clarke commented (see BioNews 1318), the offer of PES may exploit (prospective) parents' tendencies of procreative beneficence. Certainly, some of its marketing seizes upon this.

In contrast to procreative choice, there is acceptance, which may be framed in terms of an ethic of 'openness to the unbidden': a disposition of welcoming others in all their uniqueness and particularity. Demonstrating this ethic, patients and clinicians in the same aforementioned study discussed unconditional love and acceptance as defining features of a (good) parent. Their comments also indicated that they valued human diversity in terms of experiences and perspectives. Several patients and clinicians also raised concerns about control and 'playing god'.

Compared to other tests for rarer chromosomal or monogenic conditions, PES, with its broad capacity to screen embryos for the genetic chances of a plethora of (common) complex conditions and traits, exacerbates the tension between choice and acceptance among greater swaths of (prospective) parents. This tension between choice and acceptance may conflate one's desire for the best for a child with a desire for the 'best' child. And that's against a backdrop of uncertainty as to whether PES can assist in either endeavour, considering its multiple limitations.

When considering the use of PES, (prospective) parents should not only be made aware of its limitations but also explore this tension between choice and acceptance to contemplate what they really want for their offspring.

Any opinions expressed above do not represent those of my institutional affiliation.