Split Opinion on Polygenetic Embryo Screening in in Vitro Fertilization

Three out of four U.S. adults favor the use of new technologies that estimate the likelihood that a future child will develop one of several diseases influenced by genes – such as diabetes, heart disease and depression – before implanting an embryo during in vitro fertilization (IVF). This is according to a new opinion poll conducted by researchers at Harvard Medical School. The results of the poll, to be published in JAMA Network Open on May 14, underscore the need for public education and discussion about the positive and negative impacts of these ethically controversial technologies, the researchers said.

Polygenic Embryo Screening

Although the approach known as polygenic embryo screening is not yet available at most IVF clinics, some companies have begun offering such estimates – or risk assessments – to estimate disease risk, the researchers noted. “Polygenic embryo screening is largely unregulated in the United States, and without proper context and targeted patient education, risk assessments can create false expectations,” said first author Rémy Furrer, a research fellow in bioethics in the Department of Global Health and Social Medicine at HMS’s Blavatnik Institute.

Nearly three-quarters of respondents said they supported the use of such screenings to assess the risk of a future child developing a physical or mental health condition, such as heart disease, diabetes or depression. However, that number dropped when respondents were presented with various concerns for the individual and society. Far fewer respondents endorsed the use of the technology to predict traits not related to disease, such as intelligence, height and skin color. The results suggest that better educating people about the current shortcomings and implications – including regulating the promises that companies can make – will dampen optimism and help ensure that these technologies are implemented in a scientifically sound, ethical and equitable manner as they develop, the authors said.

How Accurate Are Polygenic Risk Assessments?

To date, patients undergoing IVF have been able to decide which embryos to implant based on DNA tests that detect chromosomal abnormalities such as Down syndrome and diseases caused by mutations in a single gene, such as cystic fibrosis. Such screenings, known as preimplantation genetic diagnostics, are well established and widely used. In contrast, polygenic embryo screening involves estimating probabilities for conditions and traits influenced by many gene variants, each increasing or decreasing the risk by a small amount.

Experts disagree on how useful this technology might be in the future, but at present there are still significant limitations in accuracy. Polygenic conditions arise from various combinations of genes, environment and behaviors in ways that are not yet fully understood. The American College of Medical Genetics and Genomics has stated that polygenic embryo screening is not yet ready for clinical use. It is this gap between the state of science and the increasing availability of such tests that prompted Furrer and his colleagues to conduct the survey. They hope the results will inspire professionals to advocate for more informed dialogue and guidance on these technologies.

Results

The survey was based on the team’s interviews with IVF patients and reproductive health professionals. The questions included lists of conditions, characteristics and potential effects for participants to comment on. The survey also made it clear that polygenic risk assessments could be used simply for information, to prepare for a future child or to select an embryo for implantation.

The first part of the study surveyed more than 1,400 participants who were representative of the general U.S. population in terms of age, gender, and race/ethnicity. The study was conducted between March and July 2023. The results showed, among other things, that 72 percent of respondents generally supported the use of polygenic embryo screening. 17 percent were ambivalent and 11 percent opposed. 77 percent supported the selection of embryos based on the risk of certain physical health conditions. 82 percent said they would be at least somewhat interested in undergoing polygenic embryo screening if they were already undergoing IVF. Thirty percent said they would consider IVF to gain access to polygenic embryo screening. Agreement to use risk assessments to prepare for a child was higher than to select an embryo.

Positive and Negative Aspects

In the second part of the study, conducted from March 2023 to February 2024 with about 200 respondents, the list of potential concerns was placed either at the beginning or at the end of the survey.

The concerns were:

• Parents having false expectations about the future child.
• Promoting eugenic thinking or practices – unethical efforts to select on a large scale for traits deemed desirable.
• Stigmatizing certain traits and conditions seen as less desirable.
• Treating embryos like a product by selecting for preferred genetic odds for disease or traits.
• Risk assessments are not equally relevant to all ethnicities due to the Eurocentric nature of many genetic databases.
• Unequal access to the technology due to high costs.
• Low accuracy of genetic estimates for diseases or traits.
• Reduced diversity of the human population.
• Potential for genetic parenting – parents consciously or unconsciously shaping their children’s environment based on genetic estimates.
• Confusion about how to interpret and use test results.
• Guilt over decisions if the child develops a particular condition or trait.
• Discarding embryos.
• Feeling pressured to use the technology.

In the second survey, respondents who were presented with the list at the beginning indicated less overall approval (28 percentage points less) and greater uncertainty (24 percentage points more) regarding polygenic embryo screening than those who were presented with the list at the end – a result that underscores the importance of education and the framing of public discourse.

Striking the Right Balance

Some of the survey results are nuanced, the authors say, and should not be taken as unqualified public support or opposition to polygenic embryo screening. These results provide a first glimpse of public opinion based on a limited presentation of the technology. Future research needs to examine how opinions develop.

For example, the team recommends further research into what it means that a majority of respondents endorse polygenic screening to select embryos, but also express strong concerns about a slide into eugenics. It will also be important to explore the role that personal and group values, such as reproductive freedom and autonomy, play in shaping public opinion, the authors say. The authors conclude that the work highlights the need to educate not only the public and IVF patients, but also clinicians and genetic counselors, who need to be prepared for the rising tide of questions about the potential benefits, current limitations, and concerns associated with polygenic embryo screening.