The objective of this investigation was to determine the inter- and intraobserver agreement when assessing embryo quality.METHODS
This investigation included 4002 cleaved embryos from 7535 oocytes retrieved in 688 patients undergoing IVF cycles in a multicentre trial. Embryos were evaluated locally at the inverted microscope at 28, 44 and 68 h (±1 h) post-insemination. Digital images of the embryos were assessed centrally by three blinded embryologists. To assess reproducibility, 215 randomly selected cleaved embryos from 33 patients were re-evaluated by the three central embryologists.RESULTS
The interobserver agreement among the central embryologists (using the same method of evaluation; 2D images) was good for classification of top-quality embryos (kappa 0.71–0.73), excellent for classification of normally developed embryos (kappa 0.83–0.86) and good–excellent for classification of transferable embryos (kappa 0.78–0.82). The interobserver agreement between local and consolidated central assessment (different methods of evaluation, inverted microscopy versus 2D images) was good for all three embryo classifications (kappa 0.64–0.79). The intraobserver reproducibility for all three overall embryo classifications was excellent for the consolidated central assessment (kappa 0.80–0.91).CONCLUSION
Embryo quality can be determined with a good degree of interobserver agreement independently of the method of evaluation. Embryologists classify embryos with excellent intraobserver reproducibility.