Does timing matter? : Hi just looking... - Fertility Network UK

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Does timing matter?


Hi just looking for advice, ladies 😊😊

When you have a frozen transfer with all the drugs , does it matter what day of your cycle the embryo goes back in ? 😘😘😘

44 Replies

Of course it does! There’s only a couple of days when the uterus is more ‘receptive’, which is when, in nature, the fertilised egg travels to the uterus to implant....and that happens 5 day after ovulation. So clinics use that principle to calculate the best time for transfer! 😉

Thank you it’s but should it be a certain day like 22 / 24 25 day of your cycle xxx

It depends from when you ovulate/ have egg’s 5 days after that xx

It’s a frozen cycle donor embryo xx

Then it’s 5 days after the take the eggs from the donor...

Sorry you said head is not working today! Anyway, they use the same principle of a fresh cycle....usually ovulation is between day 15-17 of cycle, so they calculate 5 days after that in your cycle (which is medicated so under their control). They have scanned you so they know how’s the lining etc....when the lining is ready they transfer!

Yes thanks , my last cycle was cancelled due to low progesterone, but they would of been doing the transfer on day 26 which I now think would that of been to late anyway xx

Yes agree, way too late! The first time I got pregnant with a FET, my transfer was on day 21 of cycle. Again, my last transfer (last week) was done on day 21 of cycle.

Thank you, I thought I was going nuts xxx

Only in a natural cycle.xx

I was confused by this too. I had my transfer booked in for a specific date (which turned out to be day 22 of cycle). Seemed a bit late to me, but I think it ties in with available lab dates. When I asked the nurse about the timing, she said it needed to be after been on progesterone for 5 days. I've also read that there is a implantation window (if I remember correctly - 6 to 10 days after ovulation), which would be the day after transfer. So I'm thinking it is timed in with that. Think the drugs control much of it, so there is a transfer window. Best of luck x

Thanks , but when your on the drugs how do you when you’re ovulating? Xxx

Cmc2020 in reply to Angels2us

They give a trigger injection to make you ovulate so they know when you will ovulate

Angels2us in reply to Cmc2020

No my Clinc doesn’t though xx

Cmc2020 in reply to Angels2us

I don’t know then that’s what I done xx

Angels2us in reply to Cmc2020

Ok thanks

Sorry might have confused things with mentioning ovulation. I really meant - when ovulation would usually happen. With the frozen transfer, the drugs prevent ovulation. From what I've worked out, the transfer window seems to be day 20 to 24, and mine was day 22, so maybe they aim for the middle day. That's just my protocol tho, may be different for others..

Oh right, was you on a long protocol?

No short protocol, but doesn't seem that short, lol 😂 Have you been given a transfer date yet?

No I should of had my transfer last Tuesday which would of been day 26 , but my levels of progesterone was so low the day before we decided to cancel it , but I just thinking now about things and was that to late anyway to transfer? Xx

Ok thanks xx

It doesnt matter! When you are doing a medicated cycle with progynova, this stops you from ovulating. It's only when your lining is thick enough (and suits the clinic) will they start the progesterone to make your uterus start to prepare itself for receiving the embryo. I usually transfer around day 24 of my cycle.xx

Thanks 😘😘

I think is matters.. lining align itself to the time that embryo blastocyst

Angels2us in reply to fay2399


With a frozen medicated cycle you won’t be ovulating, and the transfer can end up being a bit later. It depends how long it took your lining to be thick enough. The progesterone then changes the composition of the lining to make it more receptive so that has to be working for 5-7 days. If you didn’t have enough progesterone your lining wouldn’t have been receptive and even a good embryo wouldn’t have been able to attach! It doesn’t have to be an exact day because there are so many factors!

It will take a day or a few days for them to attach anyway. And that may depend on whether it was already starting to hatch before it was transferred! So there is a window of possibility not 1 exact day!

I have also heard though if you have lots of failures you can do a ERA test to check if there is a more receptive time for the transfer (like. 12 hour window! Or 24 more hours of progesterone needed!)

I would check with your clinic if they think anything like that is necessary. But if you haven’t had one yet I’m pretty sure they won’t think you’d need it. Most women have the same window!

Either way you need to progesterone to be working, so I assume they will change your progesterone this next time and all will be fine. I’m having to have lentogest as well as the pessaries this time! Will start Friday if my lining is thick enough, and transfer next Thursday (6.5 days of progesterone). I know it’s because of availability more than anything. They didn’t have many scans left so I got Friday and they only transfer on a Tuesday or Thursday! I assume that’s within my window!! It would be day 20. But I have really irregular cycles so it is really just 7 days of progesterone! My last one (failed) was day 21.

Good luck! X

Angels2us in reply to LSandJ

Thanks you xx

It’s all about the lining and progesterone with a FET under meds. I go completely natural so it does matter about ovulation etc etc.

Angels2us in reply to Vegemite

Ok thanks

I had a frozen transfer with a day 5. 7 days after starting progesterone. I did also look at weather this was too late and the nurse said they always do a week of progesterone before hand. Started My progesterone Monday evening and were fine day 4 on Friday lunch. I then had transfer Monday mid morning. During my regular cycles I ovulate roughly day 12 but the clinic said it didn’t matter been a frozen transfer? 🤷‍♀️

Fingers crossed for you.

Angels2us in reply to Nik1988

Ok thanks

Yes I got a test done to get the exact day it’s called an ERA it basically measures your window for implantation, I got this when my FET didn’t work and turns out I needed an extra day of progesterone and it worked

Angels2us in reply to flonatips


So good to hear this. My dr suggested me to do the same after three failures

My transfer was on day 17. I was on ovulation blockers until my lining was think enough for transfer. Once it was, I stopped them and had transfer 5days later x


My transfer will be next thursday which is day 16 of my cycle. I thought it seemed early but I had a scan yesterday (day 5) and lining is alreay 7.4 so dr has scheduled transfer. I will start progesterone on saturday, so that will be 6 days of progesterone before transfer.

Good luck everyone :) xx

Angels2us in reply to Isla2019

Thank you xx

Angels2us in reply to Isla2019


My dr suggested me to do ERA to determine the perfect time for transfer after 3 loss of FET. It might be worth of checking it

My FET will be done on day 14 my cycle. Day one was the day I started progynova according to my clinic. They said that they try to mimi a regular cycle. So they would try to get to day 14. My lining was already 8.4mm on day 8 when I had a scan, I started progesterone on day 9.

God that’s a lot of difference to mine , thank you xx

HMKing in reply to Angels2us

Hi I wanted to message Cus I had exactly the same worries as you...

basically I have had success with transfers on day 19 of my cycle. Sadly I did loss them with hematomas. However I changed Clinic due to travelling times and had a transfer planned for cycle day 25!!! Was mortified. However, progynova stops your natural ovulation if it’s working and you lining is looking good. When they are happy with the lining measurement they will then put you on progesterone for 5 days plus and than have the transfer. With a medicated fet it does not matter what cycle day as long as you lining looks ok.

There are tests to see when your body is most receptive like others have said and that might be worth doing if you have reoccurring failures.

I looked into the same situation and we are in safe hands even on a later day in the cycle xx

Thank you so much for getting back to me , it’s all such a worry, and we just never know, but this forum is so helpful to speak to people what give you advice , and know exactly what we are all going through, hope all works good for your self xxx

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