The effects of differences in trophectoderm biopsy techniques and the number of cells collected for biopsy on next‐generation sequencing results

Abstract

Purpose To examine how differences in trophectoderm biopsy techniques affect the frequency of mosaic embryos and sequencing results. Methods We examined differences in next‐generation sequencing (NGS) analysis results among operators or according to biopsy technique. Additionally, we determined the cut‐off for the number of collected cells to predict the occurrence of mosaicism. We collected cells according to the cut‐off value and examined whether there was a difference in the NGS analysis results between the pulling and flicking methods. Results There was no difference in the NGS analysis results among the operators. Regarding re‐biopsy, changes in the mosaic were observed in all specimens. The cut‐off value for the number of collected cells was five, and when more than five cells were collected, there was no difference in the NGS analysis results between the two methods. Conclusions We demonstrated that if trophectoderm biopsy techniques and NGS are stable, the cell collection location has a greater effect on NGS results than the biopsy technique.

The Assessment of Methods for Preimplantation Genetic Testing for Aneuploidies Using a Universal Parameter: Implications for Costs and Mosaicism Detection

“…1), while even modest differences affected detection of mosaicisms (Fig. 3), and concordance studies such as those with blastocyst rebiopsy samples [37][38][39][40] could benefit from normalization of noise, as in this study. However, currently there are no guidelines how to deal with technical noise in mosaicism studies 2 .…”

“…Indeed, biopsy techniques significantly affect the pregnancy outcome according to data from different fertility centers 3,[48][49][50] and sub-optimal biopsy techniques could cause damage to embryos 2,[48][49][50] . Blastocysts that are not particularly high in quality are especially susceptible to damage 40 and there is no standardization of blastocyst biopsy procedures between the centers 20 , again increasing variability. There is no standardized system to interpret and report PGT-A data either 2 .…”

Impact of Freeze-Thawing, Cell Collection, and Laser Irradiation Cycles on Mosaicism Occurrence in Preimplantation Genetic Testing for Aneuploidy

“…Collecting an insu cient number of cells might result in inaccurate analysis; in contrast, collecting more cells than required, as when using the icking method, can cause signi cant damage to the blastocyst. We previously reported that the number of cells needed to be collected for adequate analysis while not damaging the embryo was 5 [7]. Furthermore, NGS analysis was stable at our institute, irrespective of which technician performed the experiment.…”

“…A biopsy is generally performed by aspirating the required amount of TE cells and cutting them by laser irradiation (pulling method) or rubbing them into a holding pipette ( icking method). In this study, we used the pulling method [9] as previous studies indicated that the icking method collects more TE cells than those obtained by the pulling method [7]. The pulling method irradiates the targeted area with a laser, making cell collection easy to control and, thus, ensuring a more accurate collection of the intended number of cells.…”

“…Incidentally though, biased analyses have been reported among various institutions [5]. Mosaicism may also be in uenced by the number of cells collected and the site of collection [7], possibly due to the biopsy procedures involved. According to studies that have used next-generation sequencing (NGS), approximately 10-20% of PGT-A results were classi ed as mosaics [2,8].…”