A zygote undergoing first mitosis which has not been completed by 25 h post-insemination. The mitotic groove can be seen. This embryo should still be assessed as a 1-cell embryo.
Figure 212
The first embryo division nearing completion but the two daughter cells are still not separated. This should be assessed as a 2-cell embryo.
Figure 213
A 2-cell embryo with evenly sized blastomeres each containing one nucleus. Generated by ICSI but was not transferred.
Figure 214
A 3-cell embryo with one larger blastomere and two smaller blastomeres, i.e. it has a stage-specific cell size (see Section C). The embryo was generated by ICSI but was not transferred.
Figure 215
A 4-cell embryo with four evenly sized blastomeres each one containing one nucleus. Generated by ICSI. The embryo was transferred and implanted.
Figure 216
A 5-cell embryo where one cell is slightly out of focus. There is a slight difference in cell size but not significant enough to be called an uneven sized embryo. It was generated by ICSI and cryopreserved.
Figure 217
A 6-cell embryo with four small and two larger blastomeres, i.e. it has a stage-specific cell size (see Section C). The embryo was generated by IVF and cryopreserved.
Figure 218
A 7-cell embryo in which four of the blastomeres show a single nucleus. The embryo was generated by ICSI, it was transferred and implanted.
Figure 219
An 8-cell embryo with evenly sized blastomeres with no visible nuclei. It was generated by ICSI and transferred but the outcome is unknown.
Figure 220
A cryopreserved 9-cell embryo, warmed on Day 3. One blastomere is slightly larger and one blastomere is slightly smaller than the others. It was generated by ICSI and transferred but failed to implant.
Figure 221
A 10-cell embryo with visible nuclei in some blastomeres. It was generated by ICSI and cryopreserved.
Figure 222
An embryo with more than 10 cells on Day 4. This embryo has not compacted which is unusual at this late stage. Generated by ICSI and cryopreserved.
