Incidence of haploidy and triploidy in trophectoderm biopsies of blastocysts derived from normally and abnormally fertilized oocytes

• Published in: Journal of assisted reproduction and genetics 2024-10
• Main Authors: Girardi, Laura, Patassini, Cristina, Miravet Valenciano, Jose, Sato, Yoshimi, Fagundes Cagnin, Natalia, Castellón, Jose Antonio, Cogo, Francesco, Zambon, Paola, Blesa, David, Jimenez Almazan, Jorge, Akinwole, Adedoyin, Coprerski, Bruno, Rubio, Carmen
• Format: Article
• Language: English
• ISSN: 1058-0468; 1573-7330
• DOI: 10.1007/s10815-024-03278-4

We aimed to identify the correlation between morphological pronuclear (PN) status and the genetically determined ploidy configuration in preimplantation embryos. A retrospective observational study was conducted on 1982 embryos displaying normal fertilization and 380 embryos showing an atypical PN pattern, tested for aneuploidies and ploidy status via preimplantation genetic testing (PGT) between May 2019 and May 2024. Ploidy prediction was performed using a validated targeted-NGS approach and a proprietary bioinformatic pipeline analyzing SNPs B-allele frequency information. Ploidy results were obtained in relation to the morphological PN pattern and further stratified by mode of PN observation, maternal age, and embryo quality parameters. Abnormal ploidy results in 2PN-derived embryos were 1% (n = 20/1982): 0.8% showed triploidy and 0.2% haploidy. Ploidy results in relation to PN number in atypical fertilization were as follows: 0PN (n = 150/380) associated with 87.3% of diploidy, 8.7% of haploidy, and 4.0% of triploidy; 1PN-derived blastocysts (n = 73/153) were haploid in 47.7% of cases, 6.5% were triploid, and 45.7% diploid; 2.1PN (n = 23/280) and 3PN patterns (n = 54/280) predicted a triploid result in 34.8% and 74.1% of cases, respectively. PN observation with time-lapse increased ploidy status predictivity from 28.3% to 80.4% (p