P-279 Donor oocyte recipients do not benefit from preimplantation genetic testing for aneuploidy

Abstract

Study question Do donor oocyte recipients benefit from preimplantation genetic testing for aneuploidy (PGT-A)? Summary answer The PGT-A does not improve the likelihood of live birth and time to pregnancy for recipients of vitrified donor oocytes. What is known already Oocyte vitrification has led to increased live birth from cryopreserved oocytes and has led to widespread use of this technology in donor egg IVF programs. However, oocyte cryopreservation has the potential to disrupt the meiotic spindle leading to abnormal segregation of chromosomes during meiosis II and may increase aneuploidy in the blastocyst. Therefore, PGT-A might have benefits in vitrified donor egg cycles. However, blastocysts derived from young donor oocytes are expected to be predominantly euploid, and trophectoderm biopsy may harm blastocysts compared to embryo transfer without PGT-A. Study design, size, duration Retrospective single-center study encompassing 2233 vitrified-warmed donor oocyte cycles conducted between March 2021 and August 2024 at a private Italian IVF clinic. The study included 299 donor cycles with and 1934 without PGT-A. Vitrified donor oocyte cycles were analyzed for live birth as the main outcome measure. Secondary outcomes were time to achieve pregnancy defined as the days from the egg thawing until a live birth achieved, clinical pregnancy, ongoing pregnancy miscarriage rates. Participants/materials, setting, methods The study included women aged 30-49 who underwent blastocyst single embryo transfer (SET). Trophectoderm biopsy was performed on day 5 or 6 based on embryo development. Both natural and artificial cycle SETs were considered. Exclusions were women with fibroids >3 cm, severe adenomyosis, or male partners with sperm concentration <1 million/ml. Statistical analyses included chi-square and Student’s t-tests for group comparisons. Logistic regression adjusted for confounders was used to analyze live birth rates (LBR). Main results and the role of chance The fertilization and blastulation rates were similar in both groups with PGT and no-PGT-A, respectively p = 0.24 and p = 0.49.The mean euploidy rate per recipient was 75.3% in the PGT-A group.No statistical differences were reported for age of the donor type of endometrial preparation (natural/artificial), endometrial thickness, and days of endometrial preparation.Regarding the sperm parameter in the PGT-A, the sperm concentration (mil/mL) and sperm motility was lower than no-PGT-A (p < 0.001).The live birth rate was not different in the PGT-A group 39.9% (CI95%35.31-44.74) vs no-PGT-A 42.9% (40.95-44.87), p = 0.27.The days to reach a live birth was higher in the group with PGT-A 65.5 (CI 95% 44.31-86.77) than no PGT-A 49.7 (CI95%42.52-56.95), p = 0.48.The pregnancy rate was lower in the PGT-A group 53.3% than in no-PGT-A 62.3% (p < 0.01), while no statistical differences were reported for the clinical pregnancy rate 52.33% (CI95% 47.72-56.92) vs 56.6% (CI95%54.79-58.50), p = 0.08.The miscarriage rate calculated on the pregnancy rate was 21.37%(CI95%16.44-27.00) in the PGT-A group vs 22.44%(CI95% 20.46-24.53) in the no-PGT-A group, p = 0.76.The multivariate analysis adjusted for several confounders (patients and oocyte age, BMI, male age, sperm characteristics, day of embryo transfer, endometrial thickness, PGT-A) confirmed that these factors do not influence the live birth rate. Limitations, reasons for caution The nature of the retrospective study and two different laboratories used for the PGT-A represent the principal limitation of the study. Wider implications of the findings PGT-A testing in donor oocyte-recipient cycles does not improve the chance for live birth nor decrease the risk of miscarriage. The use of PGT-A in the donor cycle does not reduce the time to reach a live birth. Further large studies are required to confirm these results. Trial registration number No