P–575 Patients with recurrent implantation failures (RIF): chromosome abnormalities in the resulting embryos

Study question Do RIF patients have the preimplantation genetic testing for aneuploidy (PGT-A) overcome their infertility condition? Summary answer PGT-A positively impact on implantation rate in RIF patients What is known already The most common definition of RIF is failure to achieve a pregnancy after three consecutive transfers of good quality embryos. This term possibly represents a heterogeneous category of infertile couples as the causes of repeated failures can be diverse. Especially intriguing is the case of patients with an age lower than 39 years for which the oocyte quality is expected not to be compromised by the well known age effect on female fertility. The chromosome analysis of the resulting embryos has been proposed as a valid method to improve implantation in the great majority of RIF patients Study design, size, duration This retrospective study included 49 patients with at least three previous consecutive implantation failures, which underwent PGT-A from January 2016 to April 2020. Both partners had a normal karyotype. Only patients with a female age below 39 years were included, who presented with a normal uterine cavity. Couples with a severe male factor were excluded. Single frozen blastocysts were transferred according to chromosomal results Participants/materials, setting, methods Maternal age was 35.5 ± 3.1 years. All blastocysts were vitrified after trophectoderm biopsy. Whole genome amplification and array comparative genomic hybridization were performed on biopsies. Only euploid embryos were transferred. The primary outcome was the live-birth delivery rate after the first transfer Main results and the role of chance Before starting a PGT-A cycle, these patients underwent 213 embryo transfers with 251 embryos replaced. A total of 264 blastocysts were analyzed, 140 of which were aneuploid (53%). Monosomy or trisomy was reported in 67 of the diagnosed samples (67/140, 48%) whereas the remaining 73 carried complex aneuploidies (73/140, 52%). The remaining 124 blastocysts (47%) were diagnosed as euploid. All patients performed an embryo transfer resulting in 28 clinical pregnancies (57%). There were 5 spontaneous abortions and the live-birth delivery rate per patient was 47% Limitations, reasons for caution This study suffers from the weakness related to retrospectivity. In addition, as euploid embryos are still cryopreserved, the delivery rate could change at completion of the cycles Wider implications of the findings: A RIF condition can be attributed, at least in a good proportion of cases, to the generation of high percentages of aneuploid embryos. In this case, the transfer of euploid blastocysts has high chances to classify this category of RIF patients has having an embryonic cause of infertilit. Trial registration number Not applicable