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

Fertil Steril. 2019 Dec;112(6):1080-1093.e1. doi: 10.1016/j.fertnstert.2019.07.1322.


Objective: To investigate whether the morphodynamic characterization of a euploid blastocyst's development allows a higher prediction 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): The average live birth rate (LBR) in the training set was 40% (N = 207/511). Only time of morulation (tM) and trophectoderm 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 = 37/67), while those with tM ≥ 80 hours and a low-quality trophectoderm resulted in a LBR of 25.5% (N = 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 morulation for embryo development, a stage that involves massive morphologic, cellular, and molecular changes and deserves more investigation.

Keywords: Blastocyst; embryo selection; euploid; morula; time-lapse microscopy.

Publication types

  • Multicenter Study
  • Observational Study
  • Validation Study

MeSH terms

  • Adult
  • Blastocyst / pathology*
  • Embryo Culture Techniques
  • Embryo Implantation
  • Embryonic Development
  • Female
  • Fertility
  • Fertilization in Vitro* / adverse effects
  • Humans
  • Infertility / diagnosis
  • Infertility / physiopathology
  • Infertility / therapy*
  • Kinetics
  • Live Birth
  • Middle Aged
  • Morula / pathology*
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Rate
  • Reproducibility of Results
  • Risk Factors
  • Rome
  • Single Embryo Transfer* / adverse effects
  • Spain
  • Time-Lapse Imaging*
  • Treatment Outcome