How viable are zygotes in which the PN are still intact at 25 hours? Impact on the choice of embryo for transfer

The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting

BACKGROUND

Many variations in oocyte and embryo grading make inter-laboratory comparisons extremely difficult. This paper reports the proceedings of an international consensus meeting on oocyte and embryo morphology assessment.

METHODS

Background presentations about current practice were given.

RESULTS

The expert panel developed a set of consensus points to define the minimum criteria for oocyte and embryo morphology assessment.

CONCLUSIONS

It is expected that the definition of common terminology and standardization of laboratory practice related to embryo morphology assessment will result in more effective comparisons of treatment outcomes. This document is intended to be referenced as a global consensus to allow standardized reporting of the minimum data set required for the accurate description of embryo development.

Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting

This paper reports the proceedings of an international consensus meeting on oocyte and embryo morphology assessment. Following background presentations about current practice, the expert panel developed a set of consensus points to define the minimum criteria for oocyte and embryo morphology assessment. It is expected that the definition of common terminology and standardization of laboratory practice related to embryo morphology assessment will result in more effective comparisons of treatment outcomes. This document is intended to be referenced as a global consensus to allow standardized reporting of the minimum dataset required for the accurate description of embryo development. This paper reports the proceedings and outcomes of an international consensus meeting on human oocyte and embryo morphology assessment. An expert panel developed a series of consensus points to define the minimum criteria for such assessments. The definition of common terminology, and standardization of laboratory practices related to these morphological assessments, will permit more effective comparisons of treatment outcomes around the world. This report is intended to be referenced as a global consensus to allow standardized reporting of the minimum descriptive criteria required for routine clinical evaluations of human embryo development in vitro.

The influence of early cleavage on embryo developmental potential and IVF/ICSI outcome

PURPOSE

To observe whether early cleavage can be a predictor of embryo developmental potential, pregnancy and implantation rates.

METHODS

A total of 9,544 embryos in 1,095 in vitro fertilization or intracytoplasmic sperm injection cycles were observed with regard to the appearance of early cleavage at 25-29 h post-insemination.

RESULTS

A significantly higher proportion of excellent quality embryos were observed in the early cleavage group compared to the late cleavage group (52.5 versus 28.9%, P < 0.01). In the early cleavage group there was also a higher rate of pregnancy per transfer compared with the late cleavage group (38.7 versus 26.3%, P < 0.01). In addition, we found that transfer of only one early cleavage embryo resulted in a high pregnancy rate (38.5%) and a low multiple pregnancy rate (18.0%).

CONCLUSION

Early cleavage is a strong indicator of embryo quality, and may be used as an additional criterion in the selection of embryos for transfer to increase pregnancy rate and reduce multiple pregnancy rate.