Trophectoderm biopsy protocols may impact the rate of mosaic blastocysts in cycles with pre-implantation genetic testing for aneuploidy

Abstract

Purpose This study aimed to analyze the impact of different biopsy protocols on the rate of mosaic blastocysts. Methods This is a retrospective cohort study which included 115 cycles with pre-implantation genetic testing for aneuploidy (PGT-A). Two groups were allocated based on the biopsy protocols: method 1 group, the zona pellucida (ZP) was drilled on day 3 embryos followed by trophectoderm (TE) biopsy; and method 2 group, the ZP was opened on day 5 or 6 blastocysts followed by TE biopsy. All biopsy samples were assessed using next-generation sequencing (NGS) at a single reference laboratory. The euploid, aneuploid, and mosaic blastocyst rates and clinical outcomes were compared. Results The mosaicism rate in the method 1 group was 19.58%, significantly higher than the method 2 group (8.12%; P < 0.05). No statistically significant difference was observed in euploid, aneuploid blastocyst rates, and clinical pregnancy rates between the two groups. Logistic regression analysis indicated that the biopsy protocols were independently associated with the mosaicism rates among all the variables. Conclusions The present study showed that different biopsy protocols may have an impact on the mosaic blastocyst rate. ZP opening on day 3 combined with TE biopsy might increase the incidence of mosaic blastocysts.

Application of Two Blastocyst Biopsy Strategies in Preimplantation Genetic Testing Treatment and Assessment of Their Effects

“…Therefore, the no-results rate of Strategy B is higher. Contrary to Shun Xiong et al (26), our results showed that Strategy A had a lower rate of mosaic blastocyst. Mosaic embryos with mosaicism <50% transplantation could lead to a healthy pregnancy, it may be related to reduced implantation rate, increased miscarriage rate, and increased risk of fetal 229 abnormalities (27,28).…”

A Mini-Review Regarding the Clinical Outcomes of In Vitro Fertilization (IVF) Following Pre-Implantation Genetic Testing (PGT)-Next Generation Sequencing (NGS) Approach

“…Illumina twelve with MiSeq [ 11 , 13 , 14 , 16 , 24 , 27 , 29 , 33 , 34 , 38 , 43 , 44 ]; three with HiSeq [ 15 , 28 , 32 ]; two with NextSeq [ 31 , 41 ]; one with sequencing-by-synthesis [ 45 ]; …”

The “mosaic” embryo: misconceptions and misinterpretations in preimplantation genetic testing for aneuploidy

“…3). This issue may be amplified by the challenges associated with genetic analysis of very few cells, biopsy procedures potentially introducing both intact cells and fragmented cellular material (artifacts) (49,50), or incomplete lysis of cells before amplification, all of which may affect the level of noise observed. Some groups (51) have begun to address the ability to distinguish signal from noise by establishing more rigorous quality control thresholds from parameters such as the median absolute pairwise difference .…”