When undergoing IVF, and after you have made it through taking all of the stimulation medications, endured monitoring and the fears and worries that go along with it, and have finally been through egg retrieval a new question suddenly pops up. In the days that can seem like years between the retrieval, getting the fertilization report, and finding out when your transfer will be you will probably ask yourself many, many times whether or not a five-day blastocyst transfer or a two or three day transfer is better. More accurately, especially if your embryos are not developing as you hoped, you may wonder if you should just go ahead and have them transferred rather than wait and see what happens in five days.
The general consensus among fertility specialists seems to be that a day five blastocyst transfer is optimal. A blastocyst is an embroyo that has developed for five to seven days after fertilization and has two distinct cell types. The transfer procedure facilitates the selection of the best quality embryos, and clinics contend that by allowing for the transfer of fewer embryos it reduces the risk of multiple pregnancy while keeping overall pregnancy rates high. The counter-point to the argument that blastocyst transfer is always better is that embryos often do better in their natural environment and that the stress of being out of the woman’s body causes the possible deterioration.
The primary factor for me personally wanting to make it to blastocyst stage even if that meant a significantly reduced number of embryo options, was the fear of another ectopic. Typically two or three day embryos are found in the fallopian tubes, not the uterus. The embryo moves into the uterus 3+ days after ovulation. Therefore, transferring blastocysts on day five means you are putting embryos back in at the stage when they would naturally be in the uterus. This was significant for me because after having an ectopic it was a prevailing fear that I would have another and it just made sense to me that waiting would help to eliminate some of the potential for implantation in my one remaining tube.
Another “benefit” of blastocyst transfer is also one reason many people would rather just go ahead and do the transfer and day 3. Some 2 or 3 day embryos do not have the capacity to become blastocyst nor a viable pregnancy. By waiting for them to make it to the blastocyst stage more often than not some of the embryos will not become viable and only the most competent ones are available for transfer on day five. Those who wait for day five and are left with no embryos to transfer inevitably wish they had given the embryo a chance to make it inside the body, rather than not have any chance at all. I am probably beginning to sound like a broken record, but here I say again – trust your doctor. I agonized over my doctor’s decision to go to five days. We had 11 fertilized and by day 5 only had 4 embryos available. Initially, I was devastated – not only because we lost 7, but because I had hoped that we had some to freeze for use at a later time. My doctor, though, throughout the procedure told us repeatedly that he would assess the embryologist’s report on day two and if he felt that none would make it to day five we would do a three day transfer but that he would make every effort to have at least one high-quality embryo to transfer on day five. When all was said and done we transferred two blastocysts that are now my healthy twins – I guess he knew what he was doing!