Key Takeaways
- Whole genome sequencing for preimplantation genetic testing (PGT-G) of embryos can help with IVF decisions
- PGT-G was more than 99% accurate and identified clinically relevant genetic disease variants in 20% of embryos that standard testing misses
- PGT-G may enhance IVF success rates
- Findings presented this week at the National Society of Genetic Counselors (NSGC) 44th Annual Conference
SEATTLE – Nov. 8, 2025 – Whole-genome sequencing for preimplantation testing can accurately spot disease-causing variants in embryos—including many that routine tests miss—giving parents more complete information during in vitro fertilization (IVF). This type of testing delivered more than 99% accuracy and identified disease-causing variants in 20% of embryos, often for conditions not covered by standard IVF testing, according to a study presented at the National Society of Genetic Counselors (NSGC) 44th Annual Conference.
Although preimplantation genetic testing with whole-genome sequencing (PGT-WGS) has been publicized as a method to select embryos for non-medical traits such as eye color, this study focuses on the benefits of PGT-WGS for identifying genetic disease. To differentiate, the researchers use the term PGT-G for “genomics”. PGT-G examines the embryo’s entire genome and can identify genetic conditions not covered by standard screening.
“PGT-G allows hopeful parents to make more informed family planning decisions by providing the opportunity to screen for thousands of clinically relevant conditions not included in other tests, such as expanded carrier screening or other PGT-WGS tests,” said Kaylene Ready, MS, CGC, lead author of the study and genetic counselor and chief product officer at Juniper Genomics, Toronto. “This state-of-the-art testing also can detect genetic changes linked to pregnancy loss or poor embryo development, helping to prioritize embryos more likely to lead to a healthy pregnancy and live birth – potentially making IVF faster and easier.”
PGT has been used for more than 20 years to test embryos before implantation in the uterus. PGT-A typically screens embryos for chromosomal issues (such as trisomy 21). Other forms of PGT screen for one condition (such as cystic fibrosis) and are limited to families known to be at risk due to their family history or previous genetic test results.
Researchers used PGT-G to test more than 200 samples from 50 embryos donated by 10 families that had completed their fertility treatment, as well as blood samples from the 20 biological parents. The results from the samples matched what was in the parents’ blood and were >99% concordant, meaning researchers got the same result from different samples of a few cells from the same embryo, as well as the inner cell mass and "remainder" of the embryo. This is important because PGT biopsies come from the outermost layer of the embryo that eventually turns into the placenta, and the inner cell mass turns into the fetus. Having samples from a biopsy and the inner cell mass with the same result demonstrates an important link between PGT-G results and the results that would be expected in a newborn. This link confirms that PGT-G results can reliably be used to predict clinical outcomes.
Excluding two conditions that the parents already were being tested for, 10 of the 50 embryos (20%) were affected with one of five pathogenic or likely pathogenic variants, increasing the risk of disease. Overall, the conditions identified include increased cancer risks, hearing loss, a muscle disorder, a brain disorder and neurofibromatosis. Standard carrier screening and other types of PGT do not detect most of these variants.
“A PGT-A tested embryo has a 55% chance of resulting in a pregnancy and live birth, while PGT-G could increase that chance to 85%,” said Ready. “PGT-G is not common, but we believe it will eventually be offered to all patients undergoing IVF. Patients likely will value its ability to detect variants associated with pregnancy loss and poor embryo development and the added reassurance of being the best clinical tool to identify genetic disease.”
News releases may contain updated data or language that does not match what is reported in the abstract.
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Media interested in viewing study abstracts, interviewing authors and/or attending sessions at the NSGC Annual Conference can contact NSGC’s PR team at 630-344-2009 or NSGCPR@pcipr.com.
About the National Society of Genetic Counselors
NSGC is the leading voice, authority and advocate for the genetic counseling profession. Membership represents more than 5,000 masters-level health professionals, who are committed to ensuring that the public has access to genetic counseling and genetic testing. For more information, visit www.nsgc.org.
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