Sunday, January 16, 2022

Preimplantation Genetic Testing for Aneuploidy: New Methods and Higher Pregnancy Rates (re-post with video)

The post below appeared originally November 1 2021, just after the annual American Society for Reproductive Medicine meeting in October. The video of Dr. Wiemer's talk was embargoed so I could not include it. However, now that the embargo has passed you can view it at the link below.


Comparison of Outcomes from Concurrent Use of 3 Different PGT-A Laboratories, Main program of ASRM 2021, Presented on October 18th by Klaus Wiemer, PhD.

Let me stress again that improved success rates resulting from higher accuracy in aneuploidy screening of embryos will affect millions of families around the world, and over 60% of all IVF families in the US.

[ NOTE ADDED NOVEMBER 12 2021: Research seminar videos from ASRM are embargoed until 12/31. So this video will not be available until then. ]

This talk describes a study of PGT-A (Preimplantation Genetic Testing - Aneuploidy, i.e., testing for chromosomal normality) using 2 different methods: NGS vs the new SNP array platform (LifeView) developed by my startup Genomic Prediction. 

The SNP array platform allows very accurate genotyping of each embryo at ~1 million locations in the genome, and the subsequent bioinformatic analysis produces a much more accurate prediction of chromosomal normality than the older methods. 

Millions of embryos are screened each year using PGT-A, about 60% of all IVF embryos in the US. 

Klaus Wiemer is the laborator director for Poma Fertility near Seattle. He conducted this study independently, without informing Genomic Prediction. There are ~3000 embryos in the dataset, all biopsied at Poma and samples allocated to three testing labs A,B,C using the two different methods. The family demographics (e.g., maternal age) were similar in all three groups. Lab B is Genomic Prediction and A,C are two of the largest IVF testing labs in the world, using NGS.

The results imply lower false-positive rates, lower false-negative rates, and higher accuracy overall from our methods. These lead to a significantly higher pregnancy success rate.

The new technology has the potential to help millions of families all over the world.

Comparison of Outcomes from Concurrent Use of 3 Different PGT-A Laboratories 
Oct 18 2021 annual meeting of the American Society for Reproductive Medicine (ASRM) 
Klaus Wiemer, PhD

While Down Syndrome population incidence (i.e., in babies born) is only ~1 percent, the incidence of aneuploidy in embryos is much higher. Aneuploidy is more likely to result in a failed pregnancy than in the birth of a Downs baby -- e.g., because the embryo fails to implant, or does not develop properly during the pregnancy. 

False positives mean fewer healthy embryos available for transfer, while false negatives mean that problematic embryos are transferred. Both of these screening accuracies affect the overall pregnancy success rate.

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