Low fertilization rate (50%), but high blastulation rate (100%)? I don't understand


I’ve got a lot of issues, but this one stumps me. I had 2 healthy children and then 5 miscarriages of 6 children. All naturally conceived. As I’m 38, I started IVF to do some freeze all cycles to preserve my fertility while we try to conquer the Recurrent Pregnancy Loss problem. So far my cycles have looked like this: [FONT=Times]
[FONT=Times]Cycle 1: 9 eggs retrieved, 6 were mature, 3 fertilized, 3 high quality blasts (2AA, 2AB, 2BB)
Cycle 2: 10 eggs retrieved, 8 were mature, 4 fertilized, 4 high quality blasts (2AA, 2AA, 2BB, 2BB)[/FONT]
They freeze them at the 2 stage. I talked to the embryologist today and she was stumped. She said that it’s very rare to get 100% of fertilized embryos make it to blast and in 2 cycles. So, it tends to indicate that one cycle wasn’t a fluke. But, as you can see, I only had 50% fertilization rate and low egg numbers and this was on maximum stims. (Antagonist cycle: 12 days of 450iu Follistim, 150iu Menopur, HCG trigger).

I just don’t get it. It doesn’t make any sense. If I have DOR, I would see poor quality eggs, right? I don’t see that. My few eggs, high stims and low AMH point to it.

Has anyone had this before? Seen it before? Have a hypothesis? Any input whatsoever would be great.


I’m old and creaky, so generally REs don’t push eggs as ancient as mine past day 3 as bad eggs is assumed to be the norm rather than the exception. For my IVF in May, I had fertilization not terribly much better than yours (out of 12 mature, we had 7 embryos), and 100% of those made it to blast. We transferred the 4 best and only 1 of them stuck. Heartrendingly, she had Trisomy 9 and passed away at 10 weeks. The other 3 embryos didn’t qualify for freezing.

For my IVF back in January, we had 100% fertilization (4 mature eggs, 4 embryos) and 100% made it to day 3, we transferred all 4 and got BFN.

For my IVF in 2010, we had sort of better than 100% fertilization (2 mature eggs, 4 embryos) and 100% made it to day 3, we transferred 2 and have a 2 year old daughter.

My eggs LOOK plentiful and good, and they make really gorgeous embryos, but clearly looks can be deceiving. Did you do any chromosome testing on the babies you’ve lost? Or are you doing PGD on the embryos from your IVF cycles?


My twins, which made it the longest to 13 weeks were 46XX, so normal. But, they were monoamniotic which carries it’s own risks. Most of the losses were too early, 5-6 weeks to do karotyping (sp?).

We’ve thought about PGD, but it is, of course, very expensive and not covered by insurance, whereas the IVFs are covered. To do it now we’d have to defrost them all, get a sample and then refreeze. That makes me nervous that the embryos would be damaged too much to recover. Plus, with only 7 I’m completely comfortable putting them all back over time and come what may. The way I figure it, PGD doesn’t actually get me any closer to baby. If I do PGD and they’re bad, we don’t put them back. If they’re bad and we put them back, there’s no successful pregnancy. Either way, if they’re bad, they’re bad. We just save a few months and, maybe, answer some questions.

I worry that the look of these can be deceiving, too. Essemkay, can I ask how old you are?


I just turned 45.

The only issue with putting back potentially chromosomally abnormal embryos is that you could end up where I am. Happily pregnant for 10 weeks with the baby of my dreams and then completely shattered. Added to the unbelievable heartbreak is the race against the clock. There was the time to do that cycle, the time I was pregnant, and the time it took to recover from the D&C. So I’ve got empty arms, an empty womb, and I’ve lost 5 months of time on a journey that is screeching towards the end limit. We’re out of money (we have always been completely out of pocket) and out of time and unless I magically end up pregnant without assistance or through unmedicated IUIs, there will be no more babies in our lives.

But you’re much much younger than I, so you don’t have that time component. And if insurance pays for your IVFs, then you don’t have the financial one, either.

Good luck!


I’m sorry. I didn’t mean to be uncaring. That’s part of the reason we’re doing freeze all cycles now, so when we go to put them back we have time. The embryos will still be from a 38 year old me even when I’m 40+.

I worry that somehow, my embryos do like yours and look great even when they’re aneuploid. I guess only time will tell.


Xerxella - I’m in a similar situation regarding fertilization and blasts. On my 1 IVF, I had 6 mature eggs, only 3 fertilized (and that was w/ ICSI). But those 3 made it to blast. I had one put back (according to the RE it was graded an ‘A’ by their lab, which he says they never do). It stuck, but resulted in a missed miscarriage at 8 weeks. Just no heartbeat at the 3rd u/s. So looking perfect and making it to blast is definitely not a guarantee. We’re going to give the two frosties a shot in a month or two. We’ll see if the less perfect ones are actually better. Have you done a reproductive loss panel to make sure you don’t have immune issues that are causing the miscarriages? Going they pregnancies and miscarriages can cause you to have problems where you didn’t before. My RE is going to test me before trying the frosties. Check out this website for a better description than I can give. http://www.rialab.com/miscarriages_prevented.php


Just saw in your signature that you have done the RPL testing. I think it’s a good idea to cover both Dr’s opinions when trying w/ your frosties.


I think so much of the grading system is speculation. I read about people getting pregnant with embies graded much worse than mine, and I had a ton thrown away because they were deemed “not good enough to freeze.” That makes me really sad, because if we want to try for another, we will have to start from scratch.

From what I’ve read, making it to blast after day 3 is mostly the responsibility of the sperm. The egg does all the work before that point. So, maybe he has really great swimmers with great DNA, and once you get a few of your eggs fertilized, he takes over and makes some nice blasts. That’s what I keep telling myself, since we have the opposite problem…I had 10 follicles and ALL fertilized and made it to day 3, but only one was deemed a “good blast” by day 5 (we did have quite a few others at blast or morula but my clinic has super high standards, as I mentioned). It’s his fault! :wink:

Just a thought. Hope you find success soon!!