Patient's question:
My husband and I are using IVF. I heard there are two types of blastocysts, D5 and D6. Could you please tell me the difference between D5 and D6 blastocysts?Doctor's answer:
After the early embryo stage, by the 5th or 6th day, the embryo develops into hundreds of cells and transforms into a blastocyst. Although blastocysts can also be graded, it's important to know that even the lowest-grade blastocysts have a higher implantation rate compared to fresh embryo transfer. A Day 5 blastocyst is an embryo that is in the process of hatching, while a Day 6 blastocyst is fully hatched. Both are relatively fragile because they lack the protection of the zona pellucida, making them prone to death or damage during the freezing and thawing process.