ESHRE PGT Consortium data collection XXII-XXIV: PGT analyses from 2019 to 2021†.

study questionWhat are the trends and developments in preimplantation genetic testing (PGT) in 2019-2021 as compared to previous years? SUMMARY ANSWER: The main trend observed in the 22nd to 24th datasets on PGT is that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT for aneuploidies (PGT-A) and concurrent PGT-M/SR/A, while for PGT for monogenic disorders (PGT-M) and PGT for chromosomal structural rearrangements (PGT-SR), single-cell targeted testing with PCR and FISH still prevails. WHAT IS KNOWN ALREADY: Since it was established in 1997, the PGT Consortium within the European Society for Human Reproduction (ESHRE) has been collecting and analysing data from mainly European PGT centres. To date, 21 datasets and an overview of the first 10 years of data collections have been published. STUDY DESIGN, SIZE, DURATION: The data for PGT analyses performed between 1 January 2019 and 31 December 2021 with a 2-year follow-up, after analysis were provided by participating centres on a voluntary basis. Data were collected using an online platform; the data reported on a per genetic analysis basis as opposed to the former cycle-based database. PARTICIPANTS/MATERIALS, SETTING,

methodsData on biopsy methods, diagnostic technologies, genetic diseases, and clinical outcomes were submitted by 45 centres. Records with multiple PGT-M and/or PGT-SR analyses or inconsistent PGT data were excluded. Embryo transfers performed within 2 years of analysis were included to calculate clinical outcomes, including stratification by biopsy day and cumulative pregnancy rates. Data analysis, calculations, and preparation of figures and tables were carried out by expert co-authors. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 14 731 PGT analyses were reported: 3782 for PGT-M, 874 for PGT-SR, 8492 for PGT-A, and 1583 for combined PGT-M/SR with PGT-A, henceforth referred to as combined testing. The use of trophectoderm biopsy increased for PGT-M (33% in 2018 to 49% in 2019-2021), remained stable for PGT-SR (33-36%), and was consistently high for PGT-A (98%) and combined cases (96%). The adoption of genome-wide or targeted technologies following whole-genome amplification (WGA) remained relatively stable for PGT-M (12-14%) and PGT-SR (44-45%), while genome-wide analysis performed on whole-genome-amplified DNA became the standard for PGT-A (99%). The combination of PGT-M/SR with PGT-A was performed either by applying a technology following WGA (74%) or by targeted methods (PCR or FISH, 24%). Diagnostic efficiency was 87% for PGT-M, 92% for PGT-SR, 98% for PGT-A, and 90% for combined testing. Pregnancy rates per embryo transfer were 26% for PGT-M, 26% for PGT-SR, 35% for PGT-A, and 36% for combined testing. Across all groups, Day 5 biopsies yielded better outcomes than Day 3 or Day 6 biopsies. LIMITATIONS, REASONS FOR CAUTION: The findings refer to data submitted by 45 participating centres and do not reflect global trends in PGT. Information on the health of babies born following PGT was not included in this manuscript. It should also be noted that final outcomes may be influenced by the number and type of centres submitting data in different years. WIDER IMPLICATIONS OF THE

findingsThe Consortium datasets provide a valuable resource for monitoring trends in PGT practice, both from a technological perspective and in terms of clinical outcomes. STUDY FUNDING/COMPETING INTEREST(S): The study has no external funding, and all costs are covered by ESHRE. There are no competing interests declared. TRIAL REGISTRATION NUMBER: NA.