DOES TROPHECTODERM BIOPSY AFFECT BLASTOCYST’S EXPANSION RATE POST THAWING?

Abstract

The expansion of blastocyst post thawing is one of an important indicator of embryo viability and affects it’s implantation potential . Previous research found that there is correlation between rate of expansion and number of trophectoderm cells.Embryo biopsy involves reducing the number of trophectoderm cells . So this study looks into the trophectoderm biopsy would affect post thawing embryo expansion as a proxy of viability. retrospective comparative study. A total of 406 vitrified/thawed blastocysts were observed from May 2019 to April 2020. Blastocysts were divided into two groups: biopsied blastocysts (n=195) and non biopsied blastocysts (n=204).Biopsy was done using flicking technique of pre-herniated blastocysts. All vitrified blastocysts were of good quality at least 4BB according to Gardner’s criteria 1999, and vitrification was done using cryotop kitazato method. We assessed the expansion rates (%) immediately post thawing (t0), after one hour (t1), and at time of transfer (t2). Data was recorded and analyzed using SPSS version -23 statistical software. There is no significant difference in the female age between the non biopsed blastocyst group (29.5 years) and the biopsed blastocyst group (30.3 years). We found no significant differences between the expansion rates of the biopsied and non biopsied blastocysts at the t(0), .t(1), and t(2).Tabled 1Non biopsied blastocyst n=209Biopsied blastocyst n=197P-valuesExpansion t(0) (%)8.6±146.9±11.20.37Expansion t(1) (%)27±24.726.4±22.30.81Expansion t(3)(%)64±37.763.9±390.84Data presented as mean ± standard deviation, Data are considered significant if p value ≤ 0.05. Open table in a new tab Data presented as mean ± standard deviation, Data are considered significant if p value ≤ 0.05. This study suggests that embryo biopsy does not seem to affect the rate of expansion of blastocyst post thawing.