Day 3 Embryos. Why we recommend going to blastocyst for transfer.
The embryos below were beautiful at Day 3 and all of them had 8 perfect cells inside, no fragmentation.
By Day 5, these embryos were still at the cells stage and had not developed much further from how they presented on Day 3.
The patients have male factor infertility and as such have seen what looks like no impact Day 1-3 but quite an impact Day 3-5. Instances like this lead us to encourage patients to extend culture to day 5 to determine if blastocysts can be made. If the embryo transfer took place on Day 3 we would not have known that these embryos would arrest.
Information like this is very helpful. Many patients worry that going to the blastocyst stage is risky, but we see much better pregnancy rates in Day 5 embryo transfers than Day 2 or 3.