Analysis of compaction initiation in human embryos by using time-lapse cinematography

J Assist Reprod Genet. 2014 Apr;31(4):421-6. doi: 10.1007/s10815-014-0195-2. Epub 2014 Mar 9.

Abstract

Purpose: To analyze the initiation of compaction in human embryos in vitro by using time-lapse cinematography (TLC), with the goal of determining the precise timing of compaction and clarifying the morphological changes underlying the compaction process.

Methods: One hundred and fifteen embryos donated by couples with no further need for embryo-transfer were used in this study. Donated embryos were thawed and processed, and then their morphological behavior during the initiation of compaction was dynamically observed via time-lapse cinematography (TLC) for 5 days.

Results: Although the initiation of compaction occurred throughout the period from the 4-cell to 16-cell stage, 99 (86.1 %) embryos initiated compaction at the 8-cell stage or later, with initiation at the 8-cell stage being most frequent (22.6 %). Of these 99 embryos, 49.5 % developed into good-quality blastocysts. In contrast, of the 16 (13.9 %) embryos that initiated compaction prior to the 8-cell stage, only 18.8 % developed into good-quality blastocysts. Embryos that initiated compaction before the 8-cell stage showed significantly higher numbers of multinucleated blastomeres, due to asynchronism in nuclear division at the third mitotic division resulting from cytokinetic failure.

Conclusions: The initiation of compaction primarily occurs at the third mitotic division or later in human embryos. Embryos that initiate compaction before the 8-cell stage are usually associated with aberrant embryonic development (i.e., cytokinetic failure accompanied by karyokinesis).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Embryo, Mammalian / cytology*
  • Embryo, Mammalian / ultrastructure
  • Embryonic Development*
  • Humans
  • Species Specificity
  • Time-Lapse Imaging*