Chromosomal meiotic segregation, embryonic developmental kinetics and DNA (hydroxy)methylation analysis reassure the safety of human oocyte vitrification in a high security closed system

Oocyte vitrification has been introduced into clinical settings without pre-clinical safety testing. In this study, we analyzed the safety of human oocyte Biopsied PBs were collected into sterile PCR tubes. The samples and positive/negative control samples were lysed, fragmented and amplified using the SurePlex whole genome amplification kit (BlueGnome, Cambridge, UK) according to the manufacturer’s instructions (www.illumina.com). Sample and reference DNA (male and female) were labelled with Cy3 and Cy5 following the manufacturer’s instructions. Labelling mixes were combined and hybridized on 24sure Cytochip (V3, BlueGnome, Cambridge, UK) for about 12 hours. Fluorescence intensity was detected using a laser scanner (Agilent scanner G2565BA), and BlueFuse Multi software was used for data processing (BlueGnome, Cambridge, UK). Each sample is compared with both a male and a female reference. Once a specific amplification was observed, autosomal profiles were analysed for gain or loss of whole or partial chromosomal ratios using a 3SD assessment, ⩾0.3log2 ratio call or both. To pass hybridization quality controls, sex-mismatched female samples had to show a consistent gain on chromosome X and a consistent loss of chromosome Y. Sex-matched female samples had to consistently show no change on either chromosome X or Y.