Blastocyst Morphology Based on Uniform Time-Point Assessments is Correlated With Mosaic Levels in Embryos

Avoiding aneuploid embryo transfers has been shown to improve pregnancy outcomes in patients with implantation failure and pregnancy loss. This retrospective cohort study aims to analyze the correlation of time-lapse (TL)-based variables and numeric blastocyst morphological scores (TLBMSs) with different mosaic levels. In total, 918 biopsied blastocysts with time-lapse assessments at a uniform time-point were subjected to next-generation sequencing-based preimplantation genetic testing for aneuploidy. In consideration of patient- and cycle-related confounding factors, all redefined blastocyst morphology components of low-grade blastocysts, that is, expansion levels (odds ratio [OR] = 0.388, 95% confidence interval [CI] = 0.217-0.695; OR = 0.328, 95% CI = 0.181-0.596; OR = 0.343, 95% CI = 0.179-0.657), inner cell mass grades (OR = 0.563, 95% CI = 0.333-0.962; OR = 0.35, 95% CI = 0.211-0.58; OR = 0.497, 95% CI = 0.274-0.9), and trophectoderm grades (OR = 0.29, 95% CI = 0.178-0.473; OR = 0.242, 95% CI = 0.143-0.411; OR = 0.3, 95% CI = 0.162-0.554), were less correlated with mosaic levels ≤20%,