Consistent results of non-invasive PGT-A of human embryos using two different techniques for chromosomal analysis. Issue 3 (March 2021)

• Record Type: Journal Article
• Authors: Lledo, Belen; Morales, Ruth; Ortiz, Jose A.; Rodriguez-Arnedo, Adoracion; Ten, Jorge; Castillo, Juan C.; Bernabeu, Andrea; Llacer, Joaquin; Bernabeu, Rafael
• Is Part Of: Reproductive biomedicine online. Volume 42:Issue 3(2021)
• Page Start: 555
• Page End: 563
• Publication Date: 2021-03
• Subjects: Cell-free DNA -- Non-invasive PGT-A -- Spent medium; Human reproductive technology -- Periodicals; Human embryo -- Periodicals; Reproduction -- Periodicals; 616.692
• DOI: 10.1016/j.rbmo.2020.10.021
• Languages: English
• ISSNs: 1472-6483

Abstract

Abstract: Research question: Are discordances in non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) results attributable to the technique used for chromosomal analysis? Design: A prospective blinded study was performed (September 2018 to December 2019). In total 302 chromosomal analyses were performed: 92 trophectoderm PGT-A biopsies and their corresponding spent embryo culture medium (SCM) evaluated by two methods ( n = 184), negative controls ( n = 8), and trophectoderm and inner cell mass biopsies from trophectoderm-aneuploid embryos ( n = 18). Trophectoderm analyses were carried out using Veriseq (Illumina), and SCM was analysed using Veriseq and NICS (Yikon). Results: Genetic results were obtained for 96.8% of trophectoderm samples versus 92.4% for both SCM techniques. The mosaicism rate was higher for SCM regardless of the technique used: 30.4% for SCM-NICS and 28.3% for SCM-Veriseq versus 14.1% for trophectoderm biopsies ( P = 0.013, P = 0.031, respectively). No significant differences in diagnostic concordance were seen between the two SCM techniques (74.6% for SCM-NICS versus 72.3% for SCM-Veriseq; P = 0.861). For embryos biopsied on day 6, these rates reached 92.0% and 86.5%, respectively. On reanalysing trophectoderm-aneuploid embryos, the discrepancies were shown to be due to maternal DNA contamination (55.6%; 5/9), embryo mosaicism (22.2%; 2/9) and low resolution in SCM-NICS (11.1%; 1/9) and in both SCM techniques (11.1%; 1/9). Conclusions: This is the first study evaluating the consistency of different chromosomal analysis techniques for niPGT-A. In conclusion, the diagnostic concordance between PGT-A and niPGT-A seems independent of the technique used. Optimization of culture conditions and medium retrieval provides a potential target to improve the reliability of niPGT-A.