Comparative analysis of the most precise technique for the chromosomal study of the embryo. Instituto Bernabeu finding to be presented at ESHRE 2020
July, 31st 2020
One of the latest scientific project carried out at Instituto Bernabeu has been accepted at the next European Society for Human Reproduction (ESHRE) congress. The aim of this research was to evaluate the accuracy of niPGT-A by comparing two different chromosome analysis techniques used to study the embryo.
The non-invasive PGT-A (niPGT-A) has evoked a great deal of interest in reproductive medicine field in recent years as it would avoid the performance of embryo biopsy in the process of preimplantation genetic diagnosis. This would reduce the impact on the embryo’s implantation capacity which, although minimal, requires highly specialized personnel and equipment. To do this, the free DNA, which is present in the culture medium where the embryo develops in vitro, is analysed.
For the validation of this new method, which uses free DNA, different techniques have been developed with varying success rates and agreement. The discrepancies found between the results of PGT-A and niPGT-A appear to be related to embryonic mosaicism, preferential aneuploid cell removal, maternal DNA contamination and the method used for analysis (amplification / detection).
The efficacy of niPGT-A is limited by technical complications associated with the low quantity and quality of DNA present in the culture medium, presenting technical challenges for genetic analysis. It is not clear which method is the most appropriate.
For this purpose, 302 chromosome analyses were carried out using two different techniques: Veriseq (Illumina) and NICS (Yikon). Both techniques showed similar results for all the parameters analysed. Therefore, the diagnostic agreement between PGT-A and niPGT-A seems to be independent of the technique used for genetic analysis. Interestingly, concordance was higher for embryos with day six biopsy. Therefore, niPGTA may be influenced by factors such as DNA contamination and embryonic mosaic. Optimization of embryo culture conditions and media recovery are potential targets for improving the reliability of IPPTN-A.
B. Lledo, R. Morales, J.A. Ortiz, A. Rodriguez-Arnedo, J. Ten, J.C. Castillo, A. Bernabeu, J. Ll. Aparicio, R.Bernabeu.