Time of morulation and trophectoderm quality are predictors of a live birth after euploid blastocyst transfer: a multicenter study

Abstract

Objective: To investigate whether the morphodynamic characterization of a euploid blastocyst’s development allows a higher predic- tion of a live birth after single-embryo-transfer (SET). Design: Observational cohort study conducted in two phases: training and validation. Setting: Private in vitro fertilization centers. Patient(s): Euploid blastocysts: 511 and 319 first vitrified-warmed SETs from 868 and 546 patients undergoing preimplantation genetic testing for aneuploidies (PGT-A) in the training and validation phase, respectively. Intervention(s): Data collected from time of polar body extrusion to time of starting blastulation, and trophectoderm and inner-cell- mass static morphology in all embryos cultured in a specific time-lapse incubator with a continuous medium. Logistic regressions conducted to outline the variables showing a statistically significant association with live birth. In the validation phase, these variables were tested in an independent data set. Main Outcome Measure(s): Live births per SET. Result(s): Theaveragelivebirthrate(LBR)inthetrainingsetwas40%(N1⁄4207/511).Onlytimeofmorulation(tM)andtrophectoderm quality were outlined as putative predictors of live birth at two IVF centers. In the validation set, the euploid blastocysts characterized by tM <80 hours and high-quality trophectoderm resulted in a LBR of 55.2% (n 1⁄4 37/67), while those with tM R 80 hours and a low- quality trophectoderm resulted in a LBR of 25.5% (N 1⁄4 13/51). Conclusion(s): Time of morulation and trophectoderm quality are better predictors of a euploid blastocyst’s reproductive competence. Our evidence was reproducible across different centers under specific culture conditions. These data support the crucial role of moru- lation for embryo development, a stage that involves massive morphologic, cellular, and molecular changes and deserves more inves- tigation. Key Words: Blastocyst, embryo selection, euploid, morula, time-lapse microscopy