I didn’t post our embryo picture yesterday, because it is seriously ugly. Witness:
Those, my friends, are super-high quality 8-cell embryos for day 3. They look like amorphous blobs. Pea and I looked at the picture before the embryologist came in to discuss the report, and both thought we were doomed. We were so sad. Serves us right for peeking.
I spent some time learning about compaction yesterday – the stage in embryo development where the distinct cell borders start to blur, as the embryo becomes a morula. From morula to blastocyst, the cell borders become redefined as cells are differentiated into their different roles (destined to become fetus, placenta, etc.). Compaction only happens once the embryo has started to transcribe its own genes – become an independently functioning entity. It’s a necessary step, usually seen by day 4 as the morula develops and divides.
There have been three studies with large transfer numbers (300-1000) looking at whether compaction on day 3 is a useful criteria for determining pregnancy rates and embryo quality, and all statistically showed that it is. Pregnancy rates in one study* were 13% higher if at least one compacted embryo was transferred, and implantation rates** with single embryo transfers were 50% for compacted versus 30% for uncompacted single embryo day 3 transfers.
This has alleviated my concern about these developing overly quickly, and renewed my relief about this cycle thus far. Nothing to do now but wait.
I’ll get a call Tuesday about how the rest of our little guys did. At least this time the statement was ‘we’ll call you and let you know how many made it to blast” compared to “we’ll call you and let you know if any make it” – the clinic has faith some of these will continue, and so do I!
*the study = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3663968/
**Note that they say implantation rates of 50%. So pregnancy rates were almost certainly a bit, or a lot, lower.