Embryo grading serves as a vital compass in this intricate journey. Some clinics may send you the embryo creation report without explaining the letters or figures in the reports. It is essential to have detailed information about embryo grading, as you may consider you have a high number of embryos, but their quality may not be promising. The Gardner Blastocyst Classification and the Standard Blastocyst Grading system are the two main approaches.
Understanding Gardner Blastocyst Classification:
Some clinics use the Gardner Blastocyst Classification, which has numbers explaining the quality of the embryos:
First Number: Stage of expansion from 1 to 4.
1 – Early blastocyst
4 – Big blastocyst with hatching
Second Number: Quality of the inner cell mass (baby-forming part) from 1 to 3.
1 – Good quality
2 – Medium quality
3 – Low quality
Third Number: Quality of the trophectoderm (placenta-forming part) from 1 to 3.
1 – Good quality
2 – Medium quality
3 – Low quality
Decoding Standard Blastocyst Grading:
Most clinics use the Standard Blastocyst Grading system, which assigns three separate quality scores to each blastocyst embryo:
Blastocyst development stage – expansion and hatching status
1: Blastocoel cavity less than half the volume of the embryo
2: Blastocoel cavity more than half the volume of the embryo
3: Full blastocyst, cavity completely filling the embryo
4: Expanded blastocyst, cavity larger than the embryo, with thinning of the shell
5: Hatching out of the shell
6: Hatched out of the shell
Inner cell mass (ICM) score or quality:
A: Many cells, tightly packed
B: Several cells, loosely grouped
C: Very few cells
Trophectoderm (TE) score or quality:
A: Many cells, forming a cohesive layer
B: Few cells, forming a loose epithelium
C: Very few large cells
It is suggested to have a consultation with your medical coordinator, IVF doctor, or embryologist and get suggestions on which blastocyst embryo has the highest success potentials. If you prefer single embryo transfer and do not wish to transfer two embryos simultaneously, inform the medical team to freeze each embryo separately, even with low quality and success potentials. While some clinics pair one good quality and one poor quality embryo, you can request single embryo freezing. If you undergo PGS/PGD on the embryos, they are frozen separately.
