Blastocyst grading - no A students here

A very common criteria for evaluating blastocysts is the Gardner blastocyst grading system.  It assigns 3 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

More info available here:

http://fertilitylabinsider.com/2011/12/understanding-the-gardner-blastocyst-grading-scale/

http://www.advancedfertility.com/blastocystimages.htm (includes pictures!)

My lab does not use the Gardner blastocyst grading system.  It just rates the blastocysts 1, 2, or 3, with 1 good (around 10% of what they use), 2 fair (around 50% of what they use) and 3 poor (less than 15% of what they use).  Those numbers don’t add up to 100 because they also use embryos that have not made it to blastocyst stage.  [Note that they retrieve more low quality embryos than they use because, hopefully, they only have to use good quality ones for those to stick.]  I think 1 very, very roughly correlates closest to AA, 2 to BB, and 3 to CC.

The lab will tell you if you have a hatching blastocyst.  So I know for some of my cycles that the blastocyst was hatching or hatched.  I don’t know if any of my day 5 embryos were hatching, so I’m going to assume they were not.  Instead, I think they were close, so I’m going to give them a rating of “4” – “Expanded blastocyst, cavity larger than the embryo, with thinning of the shell” – but they might be less.  I know that all of my day 6s were hatching or hatched. 

Emby	My lab rating	~Gardner rating	Result
1	Day 5 B2 (fresh)	4BB	Baby!
2	Day 5 B2 (fresh)	4BB	Blighted ovum
3	Day 6 B3 – hatching (frozen)	5CC	No pregnancy
4	Day 6 B3 – hatched (frozen)	6CC	Chemical pregnancy
5	Day 6 B3 (frozen)	?CC	Still on ice (lab said it looked very rough when they froze it, unlikely to survive thaw?)
6	Day 5 B2 (fresh) [chromo normal]	4BB	Anencephaly
7	Day 6 B2 – hatched (frozen) [chromo normal]	6BB	No pregnancy (implanted but failed immediately – ½ pregnant?)
8	Day 6 B3 – hatching (frozen) [chromo normal]	5CC	Two-week wait
9	Day 6 B2 (frozen) [chromo normal]	?BB	Still on ice
10	Day 6 B3 (frozen) [chromo normal]	?CC	Still on ice
11	Day 6 un-ratable [chromo abnormal]

When I look at the sample pictures of blastocysts, though, I think my ratings might be a little bit too high.  A number of the ones we have transferred look like a hot mess.  So they may not even be as good as what I have suggested above.  Or they might be better.  So far all of my frozen ones have survived the thaw.   We did not use our fifth embryo (and might never use it) because apparently it looked really bad.  So it’s possible that it’s chromosomally abnormal/will not survive the thaw.  And even if it did, it would have a super low chance of success.