JBRA Assist. Reprod. 2025;29(Suppl 1):67-67
POSTER PRESENTATION
doi: 10.5935/1518-0557.20250119

P-051. Chaotic embryos diagnosed by Noninvasive Preimplantation Genetic Testing (niPGT-A) could be suitable for transfer

Laura D. Vagnini1, Claudia G. Petersen1,2, Fabiana C. Massaro2, Bruna Petersen2, Andreia Nicoletti2, Juliana Ricci2, Camila Zamara2, Renata A. Pouza2, Bianca C. Matuella2, Carla M.F. Dias2, Elisangela V. Espirito Santo2, Ana Clara A. Egydio2, Joao B. Meziara2, Antonio H. Oliani3, Joao Batista A. Oliveira1,2, Jose G. Franco Jr.1,2

1Paulista Center for Diagnosis, Research and Training, Ribeirão Preto, Brazil
2Center for Human Reproduction Prof. Franco Jr, Ribeirão Preto, Brazil
3São Jose do Rio Preto School of Medicine FAMERP, São Jose do Rio Preto, Brazil

Objective: The results of preimplantation genetic testing for aneuploidies (PGT-A) include the diagnosis of euploid, aneuploid, mosaic and chaotic (≥6 aneuploidies) embryos. One issue that has drawn the attention of researchers is the low reproducibility of chaotic embryo results obtained with invasive PGT-A (few studies have shown an incidence of euploidy of 38-40.5% after re-biopsy). Recently, noninvasive preimplantation genetic testing (niPGT-A) has been proposed as an alternative to PGT-A, since cell-free DNA (cfDNA) could represent the embryo ploidy status better than biopsy. In the literature, there are no studies that correlate the falsepositive rate of chaotic embryos with niPGT-A. This study aimed to analyse if embryos diagnosed as chaotic through niPGT-A could be suitable for transfer.
Methods: This prospective study was conducted between December/2023 and November/2024 and included a total of 7 embryos from 7 patients (age µ:35.7±5.5years) whose culture medium was sent for niPGT-A and was previously diagnosed as chaotic. Informed consent was obtained from the patients following the Human Medical Authority regulations. Chaotic blastocysts were thawed, maintained in culture medium for 4-8 hours and their microdrop culture medium were transferred to DNase-free PCR tubes and stored at -80°C prior to genetic analysis. The embryos were subsequently vitrified again. MALBAC® technology (Yikon Genomics), which was initially used to conduct whole-genome amplification (WGA), was used again to confirm the ploidy status (ChromGo™software) of these embryos. The DNA concentration was measured using the Qubit 3.0 fluorometer (ThermoFisher Scientific). Sequencing was conducted using the Illumina MiSeq® platform.
Results: The cfDNA amplification success rate was 100%. Reanalysis of the chaotic embryos by niPGT-A revealed that 3/7 (43%) of these embryos could be suitable for transfer on the basis of genetic analysis. Table 1 shows the results.
Conclusion: In a reanalysis of chaotic embryos by niPGT-A, 43% of the embryos were classified as euploid. The presence of falsepositive results for chaotic embryos analysed by niPGT-A indicates the need for reanalysis. A normal chromosomal constitution found after the reanalysis of cfDNA in culture medium could suggest problems with previous sequencing.

 

Table 1
Table 1. Initial Diagnosis X Reanalysis: Results.