How to assess and grade embryo quality on day 3 of development?

 

Number of embryonic leaf cells

48 hours after egg retrieval, the embryo should have 2~4 cells.

About 7~10 cells in 72 hours.

 

Degree of intraembryonic fragmentation

Fragmentation, the process by which a part of an embryonic cell is separated from the nucleated part of the cell. Preferably with little or no fragmentation.

Fragmentation percentage. Embryos with too high a fragmentation rate have a lower implantation potential.

Class A: No debris: good bedding rate

Class B: <10% debris: excellent bedding rate, equivalent to Class A.

Class C: 10%~50% debris: low bedding rate.

Class D: >50% debris: very low bedding rate

 

Presence of multiple cores in embryonic leaf cells

 

◉ An embryo is multinucleate if multiple nuclei can be seen in any blastocyte on day 2 or day 3. The vast majority of multinucleate embryos have been shown to have chromosomal abnormalities.

◉ Sometimes multinucleated embryos implant and result in healthy pregnancies and the birth of normal babies. They are usually transferred to the uterus only when there are no other options.

 

 

Other factors

◉ Similar size of embryonic leaves is best. If the difference in embryonic leaf cell size is too large, the pregnancy rate will not be high.

◉ Embryonic leaf cell symmetry, preferably three-dimensionally arranged

◉ Whether or not there is partial fusion of the blastocytes. If so, the pregnancy rate is higher

◉ Embryonic leaf cell cytoplasm granularity, cytoplasm too dark pregnancy rate is worse

◉ Embryonic malformation (oval shape), poor pregnancy rate

◉ Poor pregnancy rates if embryo is too large or too small

◉ Transparencies that are too thick and have poor pregnancy rates