Progesterone before FET

[Maui2020]

This may be an obvious Q but it is really confusing me.

If for example you were having a medicated FET on a Friday, which day are you supposed to start progesterone? My last FET I started on the Sunday so I had 5 clear days days of progesterone and then transfer the next day. That was a bfn.

I’m confused as in my natural FETs at my previous clinic they started my progesterone on a Monday for a Friday transfer. So 4 days of progesterone and transfer next day. I got pregnant on one of these FETs so I know that it works.

My new clinic prefer medicated FET so I’ve gone along with it as success rates seem to be similar. However when I questioned the progesterone days with my Dr he said it equates to the same thing...?

I haven’t been advised an ERA as I’ve had a successful pregnancy but reading how even 12 hours can make a difference to receptivity I’m now freaking out a bit that I’m not matching my receptive window.

Can anyone shed light on this? Or even let me know how many days is standard to take progesterone before transfer in either their natural or medicated FET?

[RockPig]

I’m in a similar situation and discussed this exact question with my Dr. yesterday. The response was that he doesn’t recommend the ERA test because he says there isn’t any good evidence that altering the transfer day has a significant impact on the outcome. I’m not convinced but the nearest clinic that offers the test is about 400 miles away, so not really feasible for us right now anyway.

The other thing he told me that did give me some hope was that they have now introduced injectable progesterone on top of pessaries as a standard part of their protocol for 5 days before transfer because some clinics have reported better outcomes. If part of the issue with the implantation window is identifying when progesterone levels are just right then perhaps this could help?

[Maui2020 in reply to RockPig]

Hi RockPig, that’s really interesting. I tried to look for the research myself and it’s very patchy. The only thing I can gauge is that not enough is known about ERA but it looks promising. My clinic also used the injectable progesterone as standard. That now makes more sense as I was reading that endometrial receptivity is more to do with level of progesterone. Reassuring that’s what your Dr said also. It’s all so confusing and even the Drs admit there are so many unknowns but I guess we have do just do what’s in our power to control. Wish you luck with yours X

[RockPig in reply to Maui2020]

Thanks, hope yours goes well too.

[Millbanks]

Hi Maui, I have done a lot of reading in to the ERA test (I had it done and I came out as pre-receptive, so need an extra 24 hours of progesterone before transfer). One article explained it really well - basically when they transfer the embryo it sends out signals to the uterus to let it know it's there - and if the uterus isn't at the exact moment of receptivity then it won't recognise the signals, and potentially expel the embryo (even if it's top quality and chromosomally normal). So the window of transfer is really important. In regards to your question about your clinic not being specific about the time of progesterone, I've found that different clinics have different standards of time before transfer - they don't seem to all be the same at all - which seems weird to me. But the ERA research is relatively new so I guess it takes time to standardise. If you've had 2 or more failed transfers then it's something they should really look at (especially if you have PGT-A tested embryos). My consultant is convinced by the ERA test for this reason but I know not all are. xx

[Maui2020 in reply to Millbanks]

Hi Millbanks, thank you that helps. I read your response and wrote an email to my clinic, just so we make sure we have my transfer timed right. It’s crazy there is a variation between clinics when you would think timing is so important. I always find something to get really stressed about in my cycle, that’s become a given! Did your ERA then show you to need 6 days of progesterone before transfer or 5? And have you heard back at all regarding the cyst? X 🤞🏽

[Millbanks in reply to Maui2020]

Good plan - it is so strange. Oh bless you - I'm the same - there is always something!! The only thing I can think of is that until they know there is an issue they just assume that you'll fit in to the usual window - which I think is roughly 24 hours at 5 days. So anything around that window (give or take a few hours) is likely OK to them. My window is 6.5 days of progesterone, and I've had transfers before at 110 hours, 125 hours and 132 hours - it should be 156 hours.Still waiting to hear about my cyst!! xx

[sunset212]

Hi i very much agree with the BFP cycle you had with the progesterone timing of 4 days of progesterone with transfer the next day ( so in effect transfer on the same day as the 5th day of progesterone) as i had my son with this timing in 2019 although my cycle was a natural FET as i ovulate naturally on my own. I surged on the Wednesday ( ovulation was assumed on the thursday and i began my pesseries Friday morning ( twice a day) and my transfer was the Tuesday. So with a natural a cycle i can only comment on is its usual to begin progesterone the morning following ovulation day. transfers are usually scheduled LH surge + 6 . ( for a 5 day blast transfer) i think the medicated progesterone is very much started as soon as lining is thickened enough from oestrogen you are given and then you take progesterone for 5 days prior to transfer. ( in other words so the number of supplimental days matches the maturity of your uterus. Hope that helps and good luck x

[Maui2020 in reply to sunset212]

Hi Sunset.. thank you that’s spot on to what the Dr discussed with me afterwards. I was getting worried because the medicated and natural FET progesterone days weren’t matching, but he explained its more to do with how many days after ovulation that you have the transfer. So in effect the same thing. Also in natural FET the number of progesterone days is less relevant as it’s supplementary to your body’s own. I saw you are having a natural FET for your 2nd.. good luck with it! X

[sunset212 in reply to Maui2020]

Thank you i have a handful of frozen embryos in storage so fingers crossed one is a success. Good point on the natural cycle aspect i.e it being supplimentary to your own body in producing its own progesterone. All the very best. Will keep you all updated how i get on x