Optimal embryo growth stage to freeze/transfer?

[mojitoito]

Hi everyone. I haven't been on here in a while since I left the UK in October. We were planning on doing IVF in the UK, but it didn't work out for us time-wise, so we decided to do it here in Japan once we settled down. I will be starting my medicated cycle in a week or so!!! I'll be throwing out questions on here as its all quite overwhelming with it being right in front of us now (finally!).

First question.... did anyone's clinic give them the option to freeze embryos at the cleaved stage (2-3 day growth) or the blastocyst stage (5-6 day growth)? My understanding was that only the embryos that make it to 5 days get frozen. But our clinic claims it makes no difference in pregnancy rates when transferring cleaved embryos or blastocysts. They also charge more to freeze at the blastocyst stage, and also require assisted hatching when transferring the blastocyst.

I'm reading through a lot of studies online, and most say that transferring blastocysts lead to more pregnancies. I also read the assisted hatching is not necessary for younger patients (I'm 33). Maybe they do things differently here in Japan, but just wanted to double check!! Thank you ladies...

[Ivfgotadream]

My clinic has a policy of freezing at least one on day 3 so when we did a 3 cycle Package we froze our top quality day 3 from the first cycle and then on the next 2 egg collections they were frozen on day 5.

We then thawed the day 3 and cultured it to day 5 and transferred it with a thawed day 6 as they said on revising the time lapse these two embryos bear complemented each other. Both stuck and I gave birth to twins this week.

My clinic like doing it this way so that they know it’s “alive” and active when it goes back in rather than having been just thawed an hour or so before. It was the first time we had done it this way in 4 transfers and it was the only success we had so who know if it made the difference?

[mojitoito in reply to Ivfgotadream]

congratulations on the twins!! Im realizing that every clinic does it differently. so I think its a matter of researching and deciding what we want.

[Jumpppy]

Not uncommon in US to offer freeze at 2PN, day 3 or day 5. Between day 3 and 5 they have to change culture so it is more expensive the longer they grow them. The research I've seen "per cycle" (so stim + ALL transfers) is that there is no benefit (a little bit of a reduction in pregnancy rates actually) when they transfer day 5 rather than 2PN or day 3. This suggests that some embryos that would result in a pregnacy/live birth don't make it to day 5 or the extra time in culture harms the embryo (i.e. your uterus is better for culture).

Issue is that you may need more transfers transferring early, but won't negatively impact your pregnancy rate. Clinics prefer day 5 as it improves their "pregnancy per transfer" statistics.

I've had success with day 3 and day 5 and have a bunch of 2PN frozen.

Good luck - my friend had success when she took a year off to do embryo banking treatment in Japan. They had a different approach and were pickier about what they considered "viable" to transfer or as a viable pregnancy, but it worked out for her.

[mojitoito in reply to Jumpppy]

this is very interesting! I hope it won't be as hard of a decision once we find out how many eggs we retrieve. were having a hard time coping with the thought that these are potential future children, and our decision to freeze them at day 3, or day 5 could determine their lifespan! I probably should just trust the doctors/embryologist, but good to do my own research!

[Jumpppy in reply to mojitoito]

Yeah it's tough, but you sound more realistic about how it all plays out than others just starting out. Most MF results in fertilization issues or activation issues (so arrest around day 3/4). If it is just low count and not bigger issues clinic will know with fertilization rates and day 3 numbers. Of course you never know until you start in these scenarios whether there is any FF too. Best of luck

[BBHH1]

When you transfer fresh blastocyst has higher implantation rate per embryo than cleavage. But you also have less blastocyst available than cleavage because many arrest between cleavage and blastocyst stage. When you freeze/thaw, some embryos die, because the blastocyst is “stronger” they survive more, so it’s better to freeze blastocyst. I think 70% cleavage and 90% blastocyst survive the freeze/thaw. For those reason,s if you are older and have few embryos is better to transfer cleavage fresh. If you are younger and have many embryos you can freeze blastocyst and have higher chances of success per transfer.

Also, sometimes they want to do genetic testing on the blastocyst. Unless you and your husband have a known recessive disease, it’s not a good idea, because many of the ones the label as abnormal can correct themselves and turn into normal babies, so you end up wasting good embryos.

Hope that helps! Good luck!