Embryo Grading

shutterstock_192510077 [Converted]

Cleavage embryo grading (Veeck classification)

Grade 1 – embryo with blastomeres of equal size, no cytoplasmic fragmentation

Grade 2 – embryo with blastomeres of equal size, minor cytoplasmic fragments or blebs

Grade 3 – embryo with blastomeres of unequal size, none or few cytoplasmic fragmentation

Grade 4 – embryo with blastomeres of unequal size, significant cytoplasmic fragmentation

Blastocyst grading (Gardner and Schoolcraft classification)

Grade 1 – Early blastocyst; the blastocoel less than 50% of the volume of the embryo

Grade 2 – Blastocyst; the blastocoel more than 50% of the volume of the embryo

Grade 3 – Full blastocyst; the blastocoel completely fills the embryo

Grade 4 – Expanded blastocyst; the blastocoel volume is larger than that of the early embryo and the zona thinning

Grade 5 – Hatching blastocyst; the trophectoderm has started to herniate through the zona

Grade 6 – Hatched blastocyst; the blastocyst has completely escaped from the zona

ICM grading

A – Numerous and tightly packed cells

B – Several and loosely packed cells

C – Few cells

Trophectoderm grading

A – Many cells organized in cohesive epithelium

B – Several cells organized in loose epithelium

C – Few cells

Translate »