Aneuploidy and recombination in the human preimplantation embryo. Copy number variation analysis and genome-wide polymorphism genotyping.

RESEARCH QUESTION: What are the incidence and patterns of meiotic trisomies and recombination separately and in relation to each other at the blastocyst stage via single nucleotide polymorphism genotyping combined with array comparative genomic hybridization. DESIGN: Single nucleotide polymorphism microarrays were carried out on a total of 1442 blastocyst stage embryos derived from 268 fertile couples undergoing preimplantation genetic diagnosis for the purposes of avoiding transmittance of known single gene disorders to their offspring; 24-chromosome aneuploidy screening via array comparative genomic hybridization was carried out in parallel. RESULTS: One hundred per cent of meiotic trisomies identified in these embryos were of maternal origin and their incidence increased significantly with advancing maternal age (P < 0.0001). A total of 55.8% of meiotic trisomies were meiosis I-type and 44.2% were meiosis II-type. Certain chromosomes were affected more by meiosis I-type errors, whereas others experienced more meiosis II-type errors. A detailed recombination analysis was carried out for 11,476 chromosomes and 17,763 recombination events were recorded. The average number of recombination sites was 24.0 ± 0.3 for male meiosis and 41.2 ± 0.6 for female meiosis (autosomes only). Sex-specific differences were observed in the locations of recombination sites. Comparative analysis conducted between 190 euploid embryos and 69 embryos presenting maternal meiotic trisomies showed similar recombination rates (P = 0.425) and non-recombinant chromatid rates (P = 0.435) between the two categories; differences, however, were observed when analysing embryos affected with specific maternal meiotic trisomies. CONCLUSIONS: This study yielded unique data concerning recombination and the origin of aneuploidies observed during the first few days of life and provides a novel insight into these important biological processes.

The cost of a euploid embryo identified from preimplantation genetic testing for aneuploidy (PGT-A): a counseling tool.

PURPOSE: To determine the expected out-of-pocket costs of IVF with preimplantation genetic testing for aneuploidy (PGT-A) to attain a 50%, 75%, or 90% likelihood of a euploid blastocyst based on individual age and AMH, and develop a personalized counseling tool. METHODS: A cost analysis was performed and a counseling tool was developed using retrospective data from IVF cycles intended for PGT or blastocyst freeze-all between January 1, 2014 and August 31, 2017 (n = 330) and aggregate statistics on euploidy rates of > 149,000 embryos from CooperGenomics. Poisson regression was used to determine the number of biopsiable blastocysts obtained per cycle, based on age and AMH. The expected costs of attaining a 50%, 75%, and 90% likelihood of a euploid blastocyst were determined via 10,000 Monte Carlo simulations for each age and AMH combination, incorporating age-based euploidy rates and IVF/PGT-A cost assumptions. RESULTS: The cost to attain a 50% likelihood of a euploid blastocyst ranges from approximately $15,000 U.S. dollars (USD) for younger women with higher AMH values (≥ 2 ng/mL) to > $150,000 for the oldest women (44 years) with the lowest AMH values (< 0.1 ng/mL) in this cohort. The cost to attain a 75% versus 90% likelihood of a euploid blastocyst is similar (~ $16,000) for younger women with higher AMH values, but varies for the oldest women with low AMH values (~ $280,000 and > $450,000, respectively). A typical patient (36-37 years, AMH 2.5 ng/mL) should expect to spend ~ $30,000 for a 90% likelihood of attaining a euploid embryo. CONCLUSIONS: This tool can serve as a counseling adjunct by providing individualized cost information for patients regarding PGT-A.