The Promise and Peril of Genetic Screening: From Embryo Selection to Newborn Genomics

Two emerging frontiers in genetic testing are reshaping reproductive and pediatric medicine, but experts warn of significant scientific, ethical, and regulatory challenges.

Polygenic Embryo Screening

A growing number of private US companies—including Herasight, Orchid Health, and Nucleus Genomics—are offering polygenic embryo screening to prospective parents undergoing IVF. These tests use polygenic risk scores (PRS) to estimate the likelihood of embryos developing certain diseases and traits, from late-onset conditions like heart disease and Alzheimer's to non-medical traits such as height, IQ, and eye color.

The practice has drawn sharp criticism from medical organizations and experts regarding its scientific validity, clinical utility, and ethical implications. While marketed primarily in the United States, these services are not currently offered by Australian companies, though some Australian parents have sent samples overseas.

How the Tests Work

Polygenic risk scores represent a new frontier in IVF screening, distinct from existing tests that target single-gene disorders. PRS aim to predict complex traits and conditions influenced by thousands of genes. An embryo's PRS is generated from a biopsy sample, and prospective parents can use the results to select which embryos to transfer.

Scientific Validity and Limitations

Multiple expert analyses have concluded that the science of polygenic risk scores is not sufficiently reliable for embryo screening. The American College of Medical Genetics and Genomics and the American Association of Reproductive Medicine have both issued statements indicating the technology is not ready for clinical use for this purpose.

Key limitations cited by researchers include:

• Predictive uncertainty: Mathematical modeling suggests predicted benefits are minimal—a potential gain of a few IQ points or 1–3 centimeters in height.

• Population derivation: PRS are typically derived from studies of older populations who lived in different environmental conditions, which may affect accuracy for embryos raised in future environments.

• Gene-environment interaction: Traits and diseases result from lifelong interactions between genes and environmental factors such as nutrition, education, and socioeconomic status. PRS accounts only for genetic factors.

• Pleiotropy: A single gene can influence multiple traits. Selecting for one trait (e.g., higher educational attainment) might inadvertently increase risk for another condition (e.g., bipolar disorder).

Regulatory Status

In Australia, the National Health and Medical Research Council (NHMRC) recommends preimplantation genetic testing only to avoid serious genetic conditions. Using PRS for embryo selection is inconsistent with these guidelines, as it predicts future risk rather than diagnosing a current condition. The practice operates in a regulatory grey zone.

Medical Risks

IVF carries established medical risks, including increased chance of high blood pressure in pregnancy and preterm delivery. The embryo biopsy process required for DNA analysis may also affect pregnancy outcomes. Experts have noted that parents accepting these proven risks for unproven benefits face a net potential for harm.

Ethical Concerns

Critics raise several ethical concerns:

• Misleading patients: Companies may overstate the reliability and clinical value of the tests.
• Eugenics parallels: Selecting embryos for traits like intelligence has drawn comparisons to historical eugenics movements.
• Social inequality: The practice may entrench discrimination and deepen social divides.
• Decision paralysis: Parents may face complex, difficult value judgments when evaluating multiple embryos across dozens of conditions and traits.

Companies offering these services have defended them as state-of-the-art and primarily focused on disease prevention.

Newborn Genomic Screening

Current Practice

In Australia, newborns are currently offered a heel prick test (Newborn Bloodspot Screening) within 72 hours of birth, which screens for 32 manageable conditions by detecting biochemical markers and genetic signals. This test does not sequence DNA.

Genomics Australia

In July 2024, the Australian federal government established Genomics Australia, allocating $30 million over four years, to explore integrating DNA mapping into healthcare. The body is due to present 11 recommendations on the use of genomics in newborn screening to state health ministers later in 2025. The scope includes investigating personalized cancer care and assessing the risks and benefits of providing parents with a child's full genome map.

Potential Applications

Genomic newborn testing can identify risks for conditions not detected by standard screening, including:

• Rare and life-threatening genetic disorders (e.g., familial hemophagocytic lymphohistiocytosis)
• Hereditary cancers (e.g., retinoblastoma)
• Late-onset conditions (e.g., dementia, certain cancers)

Two documented case studies illustrate potential benefits:

Freddie Underhay (UK): Genomic mapping revealed hereditary retinoblastoma, a rare eye cancer not detected by standard tests, allowing early treatment.

Giselle (Australia): Through the BabyScreen+ study, Giselle received an early diagnosis of familial hemophagocytic lymphohistiocytosis, enabling a life-saving bone marrow transplant.

Ethical and Social Implications

Experts have raised several concerns regarding widespread newborn genomic screening:

• Consent: Questions exist about the ability to obtain informed consent for a newborn whose data has lifelong implications.
• Privacy and data security: Stored genetic data requires robust protection.
• Insurance discrimination: Risk profiles could affect life insurance eligibility. The Australian government plans to introduce legislation banning the use of adverse genetic test results in life insurance underwriting; this does not extend to health insurance.
• Over-diagnosis: Genomic tests may detect genetic changes that never cause disease, potentially leading to unnecessary monitoring and treatment, creating "patients-in-waiting."
• Parental burden: Complex information provided shortly after birth may cause confusion and uncertainty for new parents.
• Impact on existing programs: There are concerns that widespread genomic testing could negatively affect uptake of the established Newborn Bloodspot Screening program.

Views on Scope of Screening

Professor Zornitza Stark, clinical geneticist and co-lead of BabyScreen+, has stated there is consensus that newborns should primarily be screened for severe, early-childhood onset, and treatable conditions. BabyScreen+ currently screens for 500 additional treatable conditions but does not assess for diseases like cancer or dementia in newborns.

Dr. Jane Tiller, advisor on public health genomics at Monash University, has advocated against universal widespread newborn genomic screening, citing cost, ethical, and public health reasons. She emphasizes testing for "the right things at the right time for the right reason."

First Nations Considerations

Associate Professor Sarah Norris from the University of Sydney has noted significant concerns regarding First Nations Australians, particularly around consent for biological samples and the potential to widen health gaps. Organizations including ALIGN and NCIG are working to ensure testing is safe and culturally appropriate, with Indigenous governance deemed vital for data sovereignty rights.