Morphology of the blastocysts correlates with results of PGS

• Published in: Reproductive biomedicine online 2019-04, Vol.38, p.e32-e32
• Main Authors: Zhylkova, Ye, Feskov, O., Feskov, V., Yegunkova, O., Zozulina, O.
• Format: Article
• Language: English
• Subjects: blastocyst; morphology; NGS; PGS
• ISSN: 1472-6483; 1472-6491
• DOI: 10.1016/j.rbmo.2019.03.053

Embryo quality has always been considered an important predictor of successful implantation and pregnancy. However, knowledge of the relative impact of each morphological parameter needs to be increased, and this evaluation method has some limitations. Usually the morphologically high quality blastocysts are chosen for embryo transfer in IVF treatment. But the results of different authors about the correlation of embryo morphology with its aneuploidy are ambiguous. The aim of our study was to evaluate possible relationships among blastocyst ploidy status and standard morphology in PGS with next generation sequencing (NGS) in IVF cycles. In this study, the morphology of 183 blastocysts, obtained in 53 PGS cycles performed in 45 infertile couples from April 2016 to December 2017, with trophectoderm (TE) biopsy and NGS, were retrospectively analyzed. Totally 183 blastocysts with different morphological quality were biopsied on the 5th and 6th days of culture and outsourced to commercial reference laboratory for next generation sequencing (NGS) test. Correlation of blastocyst morphology and embryo aneuploidy was examined with Spearman coefficient. In the mentioned study60.1% of examined blastocysts were aneuploid or mosaic (110 blastocysts). We evaluated the possible relationship between the morphology of blastocysts and PGS results taking into account the quality of trophectoderm and intracellular mass (ICM). There was no correlation between the quality of ICM and blastocyst ploidy (rs = 0.329, P > 0.05). But the decrease in quality of TE significantly correlated with the aneuploidy in blastocysts (rS = 0.458, P < 0.05). During the interpretation of women's PGS results the ploidy, aneuploidy and mosaicism were taken into account. The average age of patients'was 29.2±5.7 years old. No dependence of the blastocyst aneuploidy on the age was found in mentioned group. Existing data regarding the relationship between embryo morphology and its ploidy are conflicting.Results of the present study point to a significant relationship of the trophectoderm morphology with the chromosomal abnormalities in preimplantation embryos. As no correlation between ICM morphology and blastocyst karyotype has not been found out the development of new approaches is relevant to choose the best embryo for the next PGS examination.