Why culture embryos to the blastocyst stage?
A – The longer the period of time that elapses between egg retrieval and embryo transfer, the easier it is to see differences between good and poor quality embryos. By day 5 after egg retrieval, embryos that have reached the blastocyst stage have distinguished themselves as the best quality embryos. Embryos that are not blastocysts by day 5 or 6 are poor quality and are destined to arrest in their development. Culturing embryos to the blastocyst stage allows us to transfer fewer embryos (usually two) while maintaining high rates of success. Thus the rate of multiple gestations can be reduced.
