#190 : Impact of Fertilisation Techniques and Day of Biopsy on Pre-Implantation Genetic Testing Outcomes: A Retrospective Study

Background and Aims: Pre-implantation genetic testing (PGT) is a technology utilised in assisted reproductive technologies (ART) to aid in embryo selection and reduce time to pregnancy. However, the impact on PGT outcomes of different fertilisation techniques, to date, has been the subject of a limited number of studies. Therefore, we investigated the effect of three different fertilisation methods - intracytoplasmic sperm injection (ICSI), PIEZO-ICSI, and standard in vitro fertilisation (IVF) - on PGT outcomes, with further analysis performed for day of biopsy. Method: Retrospective analysis of 760 embryos biopsied for PGT from 290 patients undergoing IVF treatment in 2021. Fertilisation was achieved via ICSI, PIEZO-ICSI, or IVF, followed by embryo culture using a sequential media system. Trophectoderm biopsy samples were analysed using a Next Generation Sequencing based assay (Illumina VeriSeq PGS). Ploidy outcomes from PGT (euploid, aneuploid, mosaic, inconclusive and no result) were interrogated for differences between fertilisation method or day of biopsy (Day 5 or 6). For analyses, frequency data of ploidy outcomes were reported as percentages and divided into two maternal age groups: <38 and [Formula: see text]38 years. Statistical differences were determined using a chi-squared test. Results: Fertilisation technique did not have a significant effect on ploidy across both maternal age cohorts (% euploid embryos: >38 years old (n=431) PIEZO-ICSI 61% vs ICSI 58% vs IVF 51%; p>0.05, and [Formula: see text]38 years old (n=329) PIEZO-ICSI 37% vs ICSI 40% vs IVF 39%; p>0.05). For both age groups, no significant differences were observed in PGT outcomes for Day 5 biopsy compared to Day 6 (% euploid embryos: <38 years old (n=431) Day 5 62% vs Day 6 54%; p>0.05, and [Formula: see text]38 years old (n=329) Day 5 45% vs Day 6 37%; p>0.05). Conclusion: The study suggests that different fertilisation techniques or the day of biopsy may not influence PGT outcomes.