Implementing Expanded Prenatal Genetic Testing: Should Parents Have Access to Any and All Fetal Genetic Information?

Should the scope of NIPT be limited by a 'threshold of seriousness'?

Non-invasive prenatal testing (NIPT) has the potential to screen for a wider range of genetic conditions than is currently possible at an early stage of pregnancy and with minimal risks. As such, there have been calls to apply a 'threshold of seriousness' to limit the scope of conditions being tested. This approach is based on concerns about society at large and the potential impact on specific groups within it. In this paper, we argue that limiting the scope of NIPT using the criterion of 'seriousness' is arbitrary, potentially stigmatises certain disabilities over others and fails to respect reproductive autonomy. We contend that concerns about expanded NIPT are more appropriately addressed by the provision of adequate information, counselling and consent procedures. We recommend a decision-making process that helps healthcare providers support prospective parents to make informed decisions about the nature and scope of NIPT screening based on their own values and social context. In addition to addressing concerns about expanded NIPT screening, this process would help clinicians to obtain legally valid consent and discharge their duty of care (including the duty to inform) in the prenatal context.

Australasian genetic counselors' attitudes toward disability and prenatal testing: Findings from a cross-sectional survey

Diagnostic genetic testing and non-invasive prenatal testing (NIPT) for conditions associated with disability are becoming increasingly available to consumers. This genetic information can be used in the disability setting to inform factors such as prognosis, management, and reproductive decision-making. Genetic counselors (GCs) play an important role in the provision of genetic testing and NIPT, and their attitudes toward disability can influence how genetic information is communicated and shape patients' responses. This study aimed to evaluate and describe Australasian GCs' experience with and attitudes toward disabilities to identify potential biases and training needs. A cross-sectional survey was distributed to 400 GCs registered with the Human Genetics Society of Australasia. Of the 106 respondents (participation rate: 26%), a significantly greater proportion were more comfortable interacting with individuals with physical disability as compared to intellectual disability (p < 0.001). GCs with personal experiences with disabilities reported significantly greater comfort interacting with people with intellectual disability than those without experience (p = 0.012). Qualitative analysis revealed discomfort was less reflective of bias than inexperience and apprehension about communicating disrespectfully. GCs believed people with disabilities experience discrimination and that having a disability could make a person stronger, wiser, and more motivated. Most GCs viewed prenatal testing for disabilities positively as it allowed for decisions regarding continuing the pregnancy and/or provided opportunity to prepare. Challenges identified for prenatal counseling included negative societal attitudes and the low visibility of disability. GCs felt that 'personal beliefs' was the primary factor influencing the decision to terminate a pregnancy affected by disability. These findings highlight important education and training needs for GCs to improve preparedness and comfort when communicating with people with a disability.

Screening embryos for polygenic disease risk: a review of epidemiological, clinical, and ethical considerations

BACKGROUND

The genetic composition of embryos generated by in vitro fertilization (IVF) can be examined with preimplantation genetic testing (PGT). Until recently, PGT was limited to detecting single-gene, high-risk pathogenic variants, large structural variants, and aneuploidy. Recent advances have made genome-wide genotyping of IVF embryos feasible and affordable, raising the possibility of screening embryos for their risk of polygenic diseases such as breast cancer, hypertension, diabetes, or schizophrenia. Despite a heated debate around this new technology, called polygenic embryo screening (PES; also PGT-P), it is already available to IVF patients in some countries. Several articles have studied epidemiological, clinical, and ethical perspectives on PES; however, a comprehensive, principled review of this emerging field is missing.

OBJECTIVE AND RATIONALE

This review has four main goals. First, given the interdisciplinary nature of PES studies, we aim to provide a self-contained educational background about PES to reproductive specialists interested in the subject. Second, we provide a comprehensive and critical review of arguments for and against the introduction of PES, crystallizing and prioritizing the key issues. We also cover the attitudes of IVF patients, clinicians, and the public towards PES. Third, we distinguish between possible future groups of PES patients, highlighting the benefits and harms pertaining to each group. Finally, our review, which is supported by ESHRE, is intended to aid healthcare professionals and policymakers in decision-making regarding whether to introduce PES in the clinic, and if so, how, and to whom.

SEARCH METHODS

We searched for PubMed-indexed articles published between 1/1/2003 and 1/3/2024 using the terms 'polygenic embryo screening', 'polygenic preimplantation', and 'PGT-P'. We limited the review to primary research papers in English whose main focus was PES for medical conditions. We also included papers that did not appear in the search but were deemed relevant.

OUTCOMES

The main theoretical benefit of PES is a reduction in lifetime polygenic disease risk for children born after screening. The magnitude of the risk reduction has been predicted based on statistical modelling, simulations, and sibling pair analyses. Results based on all methods suggest that under the best-case scenario, large relative risk reductions are possible for one or more diseases. However, as these models abstract several practical limitations, the realized benefits may be smaller, particularly due to a limited number of embryos and unclear future accuracy of the risk estimates. PES may negatively impact patients and their future children, as well as society. The main personal harms are an unindicated IVF treatment, a possible reduction in IVF success rates, and patient confusion, incomplete counselling, and choice overload. The main possible societal harms include discarded embryos, an increasing demand for 'designer babies', overemphasis of the genetic determinants of disease, unequal access, and lower utility in people of non-European ancestries. Benefits and harms will vary across the main potential patient groups, comprising patients already requiring IVF, fertile people with a history of a severe polygenic disease, and fertile healthy people. In the United States, the attitudes of IVF patients and the public towards PES seem positive, while healthcare professionals are cautious, sceptical about clinical utility, and concerned about patient counselling.

WIDER IMPLICATIONS

The theoretical potential of PES to reduce risk across multiple polygenic diseases requires further research into its benefits and harms. Given the large number of practical limitations and possible harms, particularly unnecessary IVF treatments and discarded viable embryos, PES should be offered only within a research context before further clarity is achieved regarding its balance of benefits and harms. The gap in attitudes between healthcare professionals and the public needs to be narrowed by expanding public and patient education and providing resources for informative and unbiased genetic counselling.

A Wolf in Sheep's Clothing: Idealisations and the aims of polygenic scores

Research in pharmacogenomics and precision medicine has recently introduced the concept of Polygenic Scores (PGSs), namely, indexes that aggregate the effects that many genetic variants are predicted to have on individual disease risk. The popularity of PGSs is increasing rapidly, but surprisingly little attention has been paid to the idealisations they make about phenotypic development. Indeed, PGSs rely on quantitative genetics models and methods, which involve considerable theoretical assumptions that have been questioned on various grounds. This comes with epistemological and ethical concerns about the use of PGSs in clinical decision-making. In this paper, I investigate to what extent idealisations in genetics models can impact the data gathering and clinical interpretation of genomics findings, particularly the calculation and predictive accuracy of PGSs. Although idealisations are considered ineliminable components of scientific models, they may be legitimate or not depending on the epistemic aims of a model. I thus analyse how various idealisations have been introduced in classical models and progressively readapted throughout the history of genetic theorising. Notably, this process involved important changes in the epistemic purpose of such idealisations, which raises the question of whether they are legitimate in the context of contemporary genomics.

Is It Just for a Screening Program to Give People All the Information They Want?

Genomic screening at population scale generates many ethical considerations. One is the normative role that people's preferences should play in determining access to genomic information in screening contexts, particularly information that falls beyond the scope of screening. We expect both that people will express a preference to receive such results and that there will be interest from the professional community in providing them. In this paper, we consider this issue in relation to the just and equitable design of population screening programs like reproductive genetic carrier screening (RGCS). Drawing on a pluralistic public health ethics perspective, we claim that generating and reporting information about genetic variants beyond the scope of the screening program usually lacks clinical, and perhaps personal, utility. There are both pragmatic and ethical reasons to restrict information provision to that which fits the stated purpose of the program.

Managing Prognosis in Precision Medicine: Utility, Imagination, and Communication

Research on how physicians predict and communicate prognosis focuses primarily on end-of-life care. Unsurprisingly, as genomic technology gains traction as a prognostic tool, the focus has also been on terminality, with research focused on how genetic results may be used to terminate pregnancies or redirect care towards palliation for neonates. However, genomic results also have powerful impacts on how patients who live prepare for their futures. Genomic testing provides broad-reaching and early—albeit complex, uncertain, and shifting—prognostic information. In this essay, we argue that as genomic testing occurs earlier and increasingly in a screening context, researchers and clinicians must strive to understand and manage the prognostic implications of results. While our understanding of the psychosocial and communicational aspects of prognosis in symptomatic populations is incomplete, it has progressed further than our understanding in a screening context and therefore provides useful lessons and feasible opportunities for further research. By providing an interdisciplinary and inter-specialty perspective on the psychosocial and communicational aspects of prognosis in genetics, we discuss prognostication with respect to genetics from the neonatal period through adulthood, highlighting medical specialties and patient populations that are especially informative for considering the longitudinal management of prognostic information in genomic medicine.

Ethical issues associated with prenatal screening using non-invasive prenatal testing for sex chromosome aneuploidy

Prenatal screening for sex chromosome aneuploidies (SCAs) is increasingly available through expanded non-invasive prenatal testing (NIPT). NIPT for SCAs raises complex ethical issues for clinical providers, prospective parents and future children. This paper discusses the ethical issues that arise around NIPT for SCAs and current guidelines and protocols for management. The first section outlines current practice and the limitations of NIPT for SCAs. It then outlines key guidelines before discussing the ethical issues raised by this use of NIPT. We conclude that while screening for SCAs should be made available for people seeking to use NIPT, its implementation requires careful consideration of what, when and how information is provided to users.

Experiences of pregnant women with genome-wide non-invasive prenatal testing in a national screening program

Pregnant women’s perspectives should be included in the dialogue surrounding the expanding offers of non-invasive prenatal testing (NIPT), especially now that technological possibilities are rapidly increasing. This study evaluated women’s experiences with the offer of genome-wide (GW) first-tier NIPT in a national screening program. A nationwide pre-and post-test questionnaire was completed by 473 pregnant women choosing between targeted NIPT (trisomies 21, 18 and 13 only) and GW-NIPT (also other findings) within the Dutch TRIDENT-2 study. Measures included satisfaction, reasons for or against choosing GW-NIPT, anxiety, and opinion on the future scope of NIPT. Most respondents (90.4%) were glad to have been offered the choice between GW-NIPT and targeted NIPT; 76.5% chose GW-NIPT. Main reasons to choose GW-NIPT were ‘wanting as much information as possible regarding the child’s health’ (38.6%) and ‘to be prepared for everything’ (23.8%). Main reasons to choose targeted NIPT were ‘avoiding uncertain results/outcomes’ (33.7%) and ‘not wanting to unnecessarily worry’ (32.6%). Nearly all respondents received a low-risk NIPT result (98.7%). No differences were found in anxiety between women choosing GW-NIPT and targeted NIPT. Most respondents were favorable toward future prenatal screening for a range of conditions, including life-threatening disorders, mental disabilities, disorders treatable in pregnancy and severe physical disabilities, regardless of their choice for GW-NIPT or targeted NIPT. In conclusion, women who chose first-tier NIPT were satisfied with the choice between GW-NIPT and targeted NIPT, and most women were favorable toward a broader future screening offer. Our results contribute to the debate concerning the expansion of NIPT.

Prospects for limiting access to prenatal genetic information about Down syndrome in light of the expansion of prenatal genomics

Down syndrome (Trisomy 21) is a mild to moderate intellectual disability. Historically, this condition has been a primary target for prenatal testing. However, Down syndrome has not been targeted for prenatal testing because it is an especially severe illness. The condition was just one that could be easily identified prenatally using the techniques first available decades ago. We are moving into an era in which we can prenatally test for a vast range of human traits. I argue that when we can test for anything, there is no longer any reason to continue targeting Down syndrome. I present an argument based on the value of nondiscrimination. It is justified to set limits on access to prenatal information if the information is going to be used for discriminatory purposes. I use the examples of (1) prenatal testing for misogynistic fetal sex selection, and (2) homophobia-motivated prenatal testing for potential homosexuality, as compelling analogies.

Views on disability and prenatal testing among families with Down syndrome and disability activists: A comparative analysis of interviews from Germany and Israel

The prenatal genetic testing arena has witnessed great changes over the past decades and has been the focus of extensive discussion of its ethical, legal, and social implications. Germany and Israel were previously known for strongly contrasting regulations and attitudes of both professionals and laypeople towards genetic testing. Based on qualitative analysis of 37 semi-structured interviews, this study compares German and Israeli family members of individuals with Down syndrome and disability activists, thereby examining the interplay between lived experience and cultural scripts and their impact on the formation of personal views toward disability and prenatal testing. We have found that the differences between Germany and Israel remain, despite the emergence of new technologies, and that family members and disability activists reflect the norms of their socio-cultural environments, thereby emphasising the role society plays in shaping the views of those with direct experience of disability.

Problems with Using Polygenic Scores to Select Embryos

Companies have recently begun to sell a new service to patients considering in vitro fertilization: embryo selection based on polygenic scores (ESPS). These scores represent individualized predictions of health and other outcomes derived from genomewide association studies in adults to partially predict these outcomes. This article includes a discussion of many factors that lower the predictive power of polygenic scores in the context of embryo selection and quantifies these effects for a variety of clinical and nonclinical traits. Also discussed are potential unintended consequences of ESPS (including selecting for adverse traits, altering population demographics, exacerbating inequalities in society, and devaluing certain traits). Recommendations for the responsible communication about ESPS by practitioners are provided, and a call for a society-wide conversation about this technology is made. (Funded by the National Institute on Aging and others.).