Embryo thaw rate

**minniemouse** · November 22nd, 2012, 08:47 AM

hi everyone,

we have 11 embryos frozen at the moment, we have never had any frozen before, they were frozen day 1 for pgd down the track, the scientist said 75% usually survive the thaw so i was wondering what others experience is.

have you lost many during the thaw ?

did the ones that survived the thaw continue to divide normally ? (for those frozen before day 5)

thanks

**Cass72** · November 22nd, 2012, 09:26 AM

Wondering the same thing myself. We have one.

**murraycod** · November 22nd, 2012, 09:50 AM

With our second stim we got to freeze 13 day 4 embryos out of 23 follies and we only got two that thawed.
We were devastated. BUT apparently day 4 don't thaw as well as the younger embryos.
Third stim we got 27follies and only 3 to freeze.
I guess I have quantity not quality.

Good luck to you xx

**minniemouse** · November 22nd, 2012, 10:15 AM

thanks murraycod that's interesting because the clinic were intially going to freeze mine day 2 but decided on day 1, their theory was they will thaw better if they hadn't started to divide, or rather if they had divided they might lose a cell or 2 in the thaw and then that would put them behind because they need them at a certain level (6-8 cell) on day 3 for the pgd and then they would also be behind in growth than what they like on day 5

**nothing2lose** · November 22nd, 2012, 10:35 AM

Never lost any during freeze or thaw.

All have thawed and grown before transfer.

Hope that helps

**juniper76** · November 22nd, 2012, 11:01 AM

From what I've read, what your clinic says is true - the earlier they are frozen, the better they thaw. There are other factors though. There are 2 methods of freezing - the slow method and vitrification. Vitrification has a better thaw rate than the slow-freeze method. The clinic's experience and skill also comes into play as it seems to be a bit of an art and some embryologists are just better at it than others.

We have had 3 frozen (slow-freeze method) embryos thawed. Two were frozen on day 2 and only 1 of those two survived the thaw and it lost a cell in the process. The third was frozen on day 3 (different IVF cycle) and it survived the thaw with all cells intact. I don't think either of them divided between thaw and transfer. Both of our FETs were BFN, but we have egg/embryo quality issues.

**Janie71** · November 22nd, 2012, 11:20 AM

Ours were frozen at day2. Of 3 that we have defrosted we only lost one and the other 2 have gone on to be successful pregnancies

Janie xxx

**Amy_jellybean** · November 22nd, 2012, 11:32 AM

I've done two Stims and one FET. Our embryo was frozen at day 2 and had no problems thawing and Continued to divide, I'm now 32 weeks and will be meeting our little man soon!

**onthefly** · November 22nd, 2012, 01:25 PM

We thawed 4 day-3 embryos and 1 did not thaw well enough, 2 did not make it to day 5 and one is my DD.

**minniemouse** · November 22nd, 2012, 02:58 PM

Thanks everyone for your replies, I'm about to go into another cycle & I have a choice of doing a short cycle now & freezing everything or doing a long cycle & having 'fresh' embryos to test (due to when the pgd date is). I'm not sure what is best & I'm worried I'll lose quite a few to thaw & pgd is such a numbers game i want as many to test as i can, so I'm not sure what to do

**Cass72** · November 22nd, 2012, 03:20 PM

Thanks everyone for your replies, I'm about to go into another cycle & I have a choice of doing a short cycle now & freezing everything or doing a long cycle & having 'fresh' embryos to test (due to when the pgd date is). I'm not sure what is best & I'm worried I'll lose quite a few to thaw & pgd is such a numbers game i want as many to test as i can, so I'm not sure what to do

My FC has a policy of you not being able to do another fresh cycle when you have in excess of XX frozen (XX because I'm not sure on the numbers - will have to check it tonight).

**minniemouse** · November 22nd, 2012, 03:32 PM

Cass72: I would be interested to hear those numbers, I asked about if there was a limit (given that we already have 11 frozen but they haven't had a chance to do anything yet so who knows how good they are), I was told there wasn't a limit & the fs had no problem with us going again because he realizes we will lose some from those 11 (& will lose a lot more if not all when they are pgd tested)

**onthefly** · November 22nd, 2012, 04:44 PM

It might be different if you have to do pgd? Good luck!!

**Amy_jellybean** · November 22nd, 2012, 08:02 PM

Yeah mine is the same with you not being able to do another fresh cycle with more than 3 in the freezer.

**~TT40~** · November 22nd, 2012, 08:36 PM

all our ones we have had frozen at day 5 have thawed fine, none stuck though, but if that was due to the thawing I dont know. One of our currently frozen ones is a day 2 (the other a day 5) havent had to defrost it though so dont know. I hope yours are successful.