Beyond appearance: Can morphologically low-grade euploid blastocysts yield successful pregnancies?

PurposeThe primary objective of this investigation is to evaluate how morphological quality affects the pregnancy outcomes in euploid embryos determined by preimplantation genetic testing for aneuploidies (PGT-A). Concurrently, as a secondary objective, we aim to identify which specific aspects of morphological evaluation exert the most significant impact on these outcomes.MethodsA retrospective analysis of 451 single euploid embryo transfer cycles at our clinic was conducted. Embryos were evaluated based on the degree of blastocyst expansion, inner cell mass (ICM), trophectoderm (TE) morphology, and the day of blastocyst vitrification. Outcomes between morphologically low-grade and high-grade embryos were compared. Additionally, the study analyzed which morphological factors most influenced pregnancy outcomes.ResultsPregnancy outcomes were significantly lower in morphologically low-grade blastocysts compared to high-grade ones. Among the morphological evaluations, the ICM assessment was significantly associated with the live birth rate.ConclusionOur study indicates that the morphological quality of euploid embryos, particularly the evaluation of the ICM, plays a crucial role in IVF-ET success. In this study, we investigated the impact of morphological evaluation on the success rates of in vitro fertilization and embryo transfer (IVF-ET) in euploid embryos. Our results indicated significantly better pregnancy outcomes for embryos with morphologically high-grade evaluations compared to those with low ones, with the assessment of the inner cell mass (ICM) being notably associated with live birth rates. This suggests the crucial role of morphological quality, especially ICM evaluation, in the success of IVF-ET with euploid embryos.