Dr. Smith replies again
You're right that many programs will transfer the embryos on day 3 when they are concerned that the embryos may not develop to the blastocyst stage. HOWEVER, its not because they feel the embryos will do better in the uterus. They know there's no scientific evidence to back up this assumption. It is because they do not want to face the patient and infom them their embryos failed to reach the blastocyst stage. They are afraid that you will think the embryos failed to grow because of suboptimal lab conditions. As I explained, the embryos fail to reach the blastocyst stage because they are genetically incapable of doing so, not because anything anybody did or didn't do. In our program, we attempt to grow ALL embryos to the blastocyst stage. We have at least 1 blastocyst stage embryo for transfer 96% of the time.
You'll notice in your research into the pactices of other programs that no programs claim that their pregnancy rates improve when failing embryos are transferred to the uterus on day 3. The rationale for a day 3 transfer is to get out from under the "blame" for the failing embryos. By transferring failing embryos on day 3, the program also transfers the responsibility for the subsequent failed cycle to the patient. It is a subtle manipulation of the patient's emotions. Here's the scenario: "We're so sorry the cycle didn't work, but you know the embryos were still growing when we transferred them. We don't know what you did to them afterwords. Wanna try again?" Using this pyschological manipulation, it becomes the patient's fault the cycle didn't work, not the programs's. See how it works?