Atypical embryo phenotypes identified by time-lapse microscopy: high prevalence and association with embryo development

Fertil Steril. 2014 Jun;101(6):1637-48.e1-5. doi: 10.1016/j.fertnstert.2014.02.050. Epub 2014 Apr 14.


Objective: To characterize atypical dynamic embryo phenotypes identified by time-lapse microscopy, evaluate their prevalence, and determine their association with embryo development.

Design: Retrospective multicenter cohort study.

Setting: Five IVF clinics in the United States.

Patient(s): Sixty-seven women undergoing IVF treatment with 651 embryos.

Intervention(s): Embryo videos were retrospectively analyzed for atypical phenotypes.

Main outcome measure(s): Identification of four groups of atypical embryo phenotypes: abnormal syngamy (AS), abnormal first cytokinesis (A1(cyt)), abnormal cleavage (AC), and chaotic cleavage (CC). Prevalence and association with embryo morphology and development potential were evaluated.

Result(s): A high prevalence of atypical phenotypes was observed among embryos: AS 25.1% (163/649), A1(cyt) 31.0% (195/639), AC 18% (115/639) and CC 15% (96/639). A high percentage of embryos with atypical phenotype(s) had good quality on day 3 (overall grade good or fair): AS 78.6% (70/89); A1(cyt) 79.7% (94/119), AC 86.4% (70/81), and CC 35.2% (19/54), but the blastocyst formation rates for these embryos were significantly lower compared with their respective control groups: AS 21.5% vs. 44.9%, A1(cyt) 21.7% vs. 44.6%, AC 11.7% vs. 43.1%, and CC 14.0% vs. 42.3%.

Conclusion(s): Embryos exhibiting atypical phenotypes are highly prevalent in human embryos and show significantly lower developmental potential than control embryos.

Clinical trial registration number: NCT01369446.

Keywords: Atypical phenotype; abnormal embryo development; embryo selection; embryo viability assessment; time-lapse microscopy.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Video-Audio Media

MeSH terms

  • Adult
  • Blastocyst / pathology
  • California
  • Cleavage Stage, Ovum
  • Cytokinesis
  • Embryo Culture Techniques
  • Embryo, Mammalian / pathology*
  • Embryonic Development
  • Female
  • Fertilization in Vitro*
  • Humans
  • Male
  • Microscopy, Video*
  • Phenotype
  • Retrospective Studies
  • Sperm Injections, Intracytoplasmic
  • Time Factors
  • Time-Lapse Imaging*

Associated data