Help! FET transfer - timing question


Hi all -
I’m in the middle of my first FET cycle. I’ve been on estrace/ delestrogen since CD3. Yesterday was CD20 and at the checkup my lining was at 9.03.
My RE plans to keep me on estrace only until CD24, then start progesterone, and to do the transfer on CD 27.
I have 4 frozen 5 day good quality embryos. My cycles are usually very normal and 28 days long.
I’m also on prednisone, lovenox, baby aspirin, folgard and vitamins right now as prescribed by Beer Center for immune issues (I have them all - NKs, uNKs, cytokines, MTHFR, etc etc).

My question: everything I have been reading on FETs indicates that the transfer is usually around the same time as it would be in a normal cycle - ie CD 21. So I am going to be doing it at a very different point in the cycle. Has anyone ever heard of this, any idea why my RE would want to do it this way? Any success or failure stories with this kind of timing? Also wondering if anyone with immune issues can speak to their experience with FET timing…

thanks for any insight!


My understanding of it is, your cycle is being medically controlled, so it can be longer if it needs to be. IF all the medication brings your hormones up to the right levels at the same time as on a regular cycle, then the timing is the same - but again, because your cycle is being medically controlled, they can stretch it out if they want to or need to, for bringing up hormone levels or increasing uterine lining thickness, etc.

Have you taken your LH phase shot yet (mine was Omnitrope for an FET, once daily for three days)? Once they have you do THAT and start taking progesterone as well, your transfer is four or five days later (for 5-day blasts) and is is set in stone. But beforehand, you can delay and take estrogen and other meds as long as your RE needs, to get you in the right physical state for them to pull the trigger, so to speak.

In sum, I think your RE is just doing it to make conditions as optimal as possible.


Well, I am certainly not an expert for FET (had only one FET cycle which ended up with pregnancy), but from my own personal experience, seems that your RE have been waiting for so long in order that your lining become thick enough for FET (I had 11mm at the moment when I started Progesterone). But, thickness is very individual and not every RE is waiting for 11mm as mine did (this is the link to April FET cycle, you can notice huge variety of lining thickness:
About number of CDs for transfer, on medicated cycle your own hormones are fully suppressed, so I guess that number of CDs of your normal cycle doesn’t have anything with medicated cycle. But, I agree with you that it is a bit unusual to wait for that long (you may check in April FET file (link above), but I don’t remember any lady who had transfer so late). What your RE says?

And, at the end (not to forget): GOOD LUCK!!! :cheer: :cheer: :cheer:


Greetings Dear D, Heather, Valleytype,

I am also slated for a FET (July at CCRM) and had this same question. I’ve been on Estrace patches/baby asprin since CD1, but it seemed like they were going to wait as late as CD 23 for my FET! Luckily, we were able to move this up a few days (tentative July 5), but with my cycles being 26 days and getting ONLY on Estrace (progestrone will be added a lil later) I’m a lil concerned about ovulating and throwing everything off.

As you can see we are only going to have one shot at this so I’m realllllllllly on edge.

Good Luck Ladies and :babydust: to all.


Thanks so much for the replies… here’s an update. I had a BW/US last week and asked the doc about the timing. He said the same thing essentially - that with the medication, the timing doesn’t really matter. My lining was at 9.3 that day (CD22) and I am getting the transfer today at CD27. He wanted the extra days to get the lining even thicker.

One strange thing is that he didn’t give me any ovulation trigger shot, as you guys mention and which seems to be the normal process… I just started progesterone on CD22 and now am getting the transfer.

So, fingers crossed that everything is still okay today with the lining, I will know soon… thanks so much for the support - and good luck Heather1977 and flygirl9999 with your next FETs… Dear D congrats on your BFP!