ASRM 2015: CCS Poster Summary
Analyses of 37,000+ Embryos with 24-Chromosome Single-Nucleotide Polymorphism (SNP)-Based Preimplantation Genetic Screening (PGS)
Rabinowitz M,1 McCoy RC,2 Demko Z,1 Simon AL,1 Ryan A,1 Kiehl M,1 Petrov DA,3 Givens C,4 Bush M5
This is a study presented at the October 2015 annual meeting of the American Society for Reproductive Medicine in Baltimore, Maryland.
This report comprises the largest reported embryo dataset from women undergoing IVF treatment with 24-chromosome SNP-based PGS (also known as Comprehensive Chromosomal Screening, or CCS). The data was gathered from 181 IVF centers with pregnancy outcome data obtained primarily from two large IVF centers, Pacific Fertility Center in San Francisco, California and Conceptions Reproductive Associates in Littleton, Colorado. Over 37,000 human embryos were analyzed by CCS at the reference laboratory, Natera, Inc. (San Carlos, California).
Embryo implantation rates, clinical pregnancy rates and live birth rates were calculated on the outcome data and analyzed primarily by maternal age category. 37,711 embryo biopsies (22,599, Day 3; 15,112, Day 5and 6) from 5,821 IVF cycles were included in this analysis, which is clearly the largest embryo genetic testing dataset ever reported.
Complex chromosomal abnormalities are more common in Day 3 embryos as compared to Day 5/6 embryos. The proportion of normal embryos is higher on Day 5/6 than on Day 3, but the total number of normal embryos on Day 5/6 is less, suggesting that chromosome abnormalities are a major reason for the drop-off in the number of normal embryos between Day 3 and Day 5/6. As expected, the numbers of normal embryos were high in women under 35, but decreased rapidly thereafter.
Genome-wide association studies with these embryos have also identified a variant region on Chromosome 4 that is strongly associated with having a large number of chromosomally abnormal embryos. Women with mitotic-error-associated genotypes at this region had significantly fewer Day 5 biopsies which is consistent with an increase in nonviable aneuploid embryos.
To see the full poster, click here.
- Carolyn Givens, M.D.