Sunday, November 7, 2010

My continuing debate on 3 versus 5 day transfer

Dr Smith replies:
You are correct that only the embryos that make it to the blastocyst stage (and beyond) can generate a succesful IVF pregnancy. In my lab, and many others, all embryos are grown to the blastocyst stage and only well developed blastocyst stage embryos are transferred to the uterus on day 5 or 6. Extra embryos are cryopreserved at the blastocyst stage.

Why aren't all programs doing this? There are numerous reasons for continuing to perform day three transfers: its cheaper, its less work for the lab, lower liability because the lab has the embryos for a shorter period of time, everybody makes it to transfer, if the cycle doesn't result in a pregnancy, the program can still look good, etc. You'll notice I didn't say anything about a day 3 transfer improving your chances of getting pregnant - it doesn't. The reason programs continue to transfer day 3 embryos is because its more convenient for the lab and the docs.

However, growing the embryos to the blastocyst stage prior to transfer does not automatically result in a pregnancy. Because the embryos have reached the blastocyst stage prior to transfer, its reasonable to assume the embryos a capable of implantation. BUT the embryos are transferred to the uterine cavity and they still must attached to the uterine wall (endometrium) and continue the implantation process for 10 ten days before a "pregnancy" is established. The attachement and implantation processes are currently beyond our control and these represent the crap-shoot in all of this.

At least with blastocyst stage embryo transfer you know the embryos are capable of implantation. When day 3 transfers are performed, its completely uncertain as to whether or not the embryos made it to the blastocyst stage (unless there's a pregnancy). If you don't become pregnant, you're left hanging. What went wrong? Were my embryos O.K.? Should I do this again??? Of course, your doc's answer will likely be "Yes" since that keeps him in business. As you can see, there's a potential sinister side to day 3 transfers...


  1. I heard that docs do day 3 transfers in part because it's more likely that they'll keep growing in the uterus as opposed to a petri dish, since "it's where they belong." I always wondered if they were just trying to appeal to my emotional, desperate side of just wanting to start growing a baby. Hmmmm....

  2. Maria, that's what my clinic told me too but I have been reading a lot and it sounds like it is a controversial issue. Dr. Smith also said "Some say that embryos are better in the uterus at day 3 while others say they are not because if you were having a baby the old fashioned way the embryo remains in the fallopian tube until day five or blast stage. And really if we think about it (Ask your RE I bet he agrees with me) the uterine environment on day 3 isn't the same as your fallopian tubes. And on top of that with what labs do regarding sequential culture systems that help grow embryos to blast -- those kinds of conditions in the lab are as close to the fallopian tubes as you are going to get. So with all that being said maybe embryos are better off in the lab until blast"

  3. I saw your comment on "As Fast as My Baby Can" asking for opinions on Day 3 vs. Day 5 transfers and thought I would pop over. I have done 3 fresh and 2 frozen IVF cycles over the last 2 years. My clinic does both Day 3 and Day 5 transfers, but seem to definitely be moving in the direction of more and more Day 5 transfers. As long as I had about 10 embryos to work with, we basically plan on doing a Day 5 transfer and then if on Day 2 or 3 it looks like none are going to make it to Day 5, they call for an early transfer on Day 3. If you have less than 10 embryos, they would likely do a Day 3 transfer.

    One of the most important things from Day 5 is that you can better select the embryos that are likely to “work.” The best looking Day 3 embryos aren’t necessarily the best looking Day 5 embryos. So the longer you wait, the better your decision is. Also, as others said, Day 5 is closer to the natural time when embryos implant. One other thing that isn’t a major driving factor, but a benefit I have seen, is that if you got a lot of eggs and may be a little hyperstimulated, the extra 2 days gives your body a little more of a chance to recover before the transfer (if you get pregnant the hyperstimulation just gets worse). All that being said, I TOTALLY UNDERSTAND that it is so difficult to watch those embryos “tucker out” and you feel like maybe they could have made it if they were in your belly!

    In my opinion, even though it is hard, I personally believe in Day 5 transfers (assuming you have enough embryos to work with and assuming you have several good looking Day 3 embryos that warrant continuing on). That being said, I also think your lab MUST be comfortable with blastocyst transfers. If this is not their normal protocol, I’m not sure I would push it. I think much of it has to do with if they have the proper culture to grow in and the experience of the embryologists. In my opinion, you might be worse off if you try and make them do something they aren’t comfortable with. Also, if you end up freezing extra blastocysts and their freeze process isn’t perfected, those blastocysts may not survive a thaw later on (they are more fragile than Day 3 embryos).

    You may want to check out Shady Grove Fertility’s website for an interesting article on this topic. They are even doing Day 6 transfers. I went for a consult there at one point and they seem to have an extremely strong research program.

    I have one story for you…a good friend of mine (who also had Stage IV Endo) had planned on transferring 2 blastocysts at Day 5. On Day 3, her embryos looked pretty crappy (those are her words). They transferred 3 Day 3 embryos, one of them made it and she has a beautiful daughter today. She asked our RE (we go to the same doc) if he thought her daughter would have made it if they hadn’t transferred until Day 5 and he said “yes.” He said even though she was “slow” or “behind” on Day 3, he firmly believed that she would have become a blastocyst in culture as well. She actually just had her second IVF baby and did a Day 5 transfer this time…so both ways worked for her!

    Like I mentioned earlier, I have been through quite a bit in the IVF world and am glad to answer any questions or provide any additional guidance along your journey. BEST OF LUCK!!