Vitrification of embryos and oocytes

They can last forever. The thing is that the tanks that we use, they need maintenance, and I would need to check them every day, and we need to see the level of the liquid nitrogen, just to keep them safe and better, but they can be a stored for a long long time.

First, we need to achieve a good survival rate. That’s the first thing that we need to do, that’s why I said we need a good protocol, we need good vitrification program to achieve results close to a 100% survival rate. After that, we’re talking about achieving pregnancy. So the answer to this question is we don’t lose any possibility because if the embryos survive, they have the same possibility to implant as the fresh embryos. When we have frozen embryos, we’re going to transfer them in an endometrium, that doesn’t have any effect of the stimulation.

I mean now with this question, we’re going to talk more about oocytes. I would say the best moment for fertility preservation would be 25 years old. We all know that young women between 25, they don’t think about this kind of treatments or something like that. This is like the last thing that they’re going to think about. So I always say this should be a present from the grandmas to their granddaughters. The grandmas could pay for a treatment like this, for a fertility preservation treatment. The thing is that you need to see every case. Patients under 35 that could be a good age for fertility preservation, so if you’re thinking about doing it, you should do it before you’re 35 because so many patients at the age of 40 don’t have as many oocytes or the quality is diminishing. They wished they knew there is something like fertility preservation back then.

This is a really good strategy in our daily routine. From the economic point of view, we’re going to have more oocytes to get embryos in the end. In our clinic, we don’t recommend this. If, patients are over 38, or 39 their quality of the embryos can be compromised already. So if we vitrify them, the only thing that we can be doing is decreasing their quality so damaging them, so that’s why we don’t recommend it. Sometimes, they don’t have a partner, and they are working really hard, or they just don’t think about having a baby now, and the thing is that you need to tell them that at the age of 39, it’s not a good technique to do because instead of preserving those oocytes we’re damaging them. To answer this question, that is a really good strategy, but you have to know the age of the patient, and you have to explain to them the problems if they are over 38-39 that we can find. Perhaps, we will vitrify 3 oocytes, and in another cycle, we’ll vitrify 3 oocytes as well, so we’ll have 6 but maybe what we have been doing is that those 3 if we used them as they are fresh, maybe we could have some embryos. By vitrifying them, we could be losing the possibility of having some embryos.

When we’re talking about oocytes donation, we prefer to use fresh oocytes, we have our own donors, and we use fresh oocytes as we prefer them. In cases, that we have a particular phenotype requirement, we need to buy them in a bank, but we prefer to have our own oocytes, that way we can perform ICSI with fresh oocytes. I prefer fresh oocytes because you need fewer oocytes to achieve a pregnancy. When you freeze the oocytes, you always need more oocytes to have the same results.

I’m not sure if today there is somebody that still uses the slow freezing method. For sure, the results are much better with vitrification. Oocytes are more difficult to vitrify than the embryos because of the size of the cell. We’re talking about one big cell, and the thing is that we need to dehydrate the cell, so all the water needs to go out and what needs to go in, is a cryoprotectant. That’s the problem with this low freezing, with the slow freezing we’re not able to take all the water out. The problem is the ice crystal formation inside the oocytes, and that can damage the oocytes, and so the survival rate will be much lower.

I mean vitrification is not an old technique, and that’s true that we don’t have embryos vitrified for a long time, but I know that there are reported cases where with this slow freezing, they have a healthy baby born after a lot of years of that freezing.

The thing is that we make like newest sperm every 72 days, so that’s not really a problem. When it comes to the oocytes and the age, it is a great problem, but when it comes to sperm, it is a lot different. I don’t know why they don’t want to accept the sperm that you have frozen, because I am sure when they’ve frozen the sperm back in Australia, they performed all the tests for the infectious diseases. But even if your husband is 50, I don’t see a problem with using a new sperm sample. When we’re talking about sperm we can test the chromosomes, we can test the DNA fragmentation, but we don’t really see if we have any infectious disease in that sperm. Once you have your sperm frozen, the quality of that sperm is going to be damaged, so you better not do too many things because you’re not going to have enough sample for ICSI or other technique that we’re going to use.

I would say the one that was 26 maybe is a little bit big. We normally plan 2-3 days before the oocytes retrieval. We like to have not more than 21-22 follicles, depending on the number of follicles that you have. Sometimes, you need to lose one, like this one f. e. sometimes you need to lose that one. I guess you have 5 follicles and 5 oocytes, 26 one is a little bit too much, but 21, 18, 17 they’re correct. The question on if the quality was compromised by waiting too long, I don’t think so, sometimes with this size, you can not even retrieve it, you just lose it. In this case, as you are 33, it is very good, and the problem is that your ovarian reserve is low, and the quality is not good because it is C and D, we don’t use the D for transfer, we could only use the C, but I don’t think this was the problem. With just one cycle, we cannot say that neither the quality was bad nor the follicles were too big, and that’s why you have Bad quality embryos.

Like I said, here we prefer to use fresh oocytes. A lot of clinics, prefer to bye the oocytes from the banks because having own donors is always a lot of work, you have to do a lot of things to have a good donor program. We always prefer that because as I’ve mentioned you will always need more vitrified oocytes to achieve pregnancy. The success rates are about the same with fresh oocytes. The only difference is that we need more oocytes.

If you are 40 years old woman and you have a very good response, you can get good quality embryos. I would always prefer the 37-year-old with frozen eggs than a 40-year-old. Because of the chromosomal abnormalities that you’re going to find when you are over the 39. This is the problem with the age of the oocytes which means the number of chromosomal abnormalities that you’re going to have in the embryos as a result. Most of our patients are over 38, so that’s why we perform the PGD which analyzes the embryos because we have a lot of embryos with chromosomal abnormalities and that results in no pregnancy, or even if you get a pregnancy, you can have a miscarriage more easily.

We perform the oocytes vitrification 2 hours after the oocytes retrieval. We prepare all the media, we prepare everything in our cabin, and we accumulate the oocytes for 1 hour and a half, and in 2 hours they should be already verified. Once you want to use those oocytes, we warm the oocytes, and we wait 3 hours after warming to perform the ICSI. We do that because that way the oocytes can recover and the quality of the embryos is better.

That depends on the clinic. We cannot perform embryo transfer over 50, but like I said if you do a transfer and you achieve a pregnancy, and we’re talking about the next year, I don’t know that depends not really on the embryologist but more on the gynaecologists because they are the ones that see the problems when you get pregnant over 50, we’re talking about obstetric problems etc.

In general, you need like 7-8 oocytes to achieve a pregnancy, and when we’re talking about vitrified oocytes, you need like 12 depending on the age. If we’re talking about oocytes from a donor we can say maybe 6 fresh oocytes, then 8-9 vitrified oocytes.

It is something that a lot of patients ask, and my answer is no, not really. They are always talking about the DHEA, folic acid that you can find in Fish, or there are some pills that you can take, but you don’t really increase the quality of your sperm. I mean you can try it because this is something that is is not bad for you or your partner.

I would like to tell you, of course, use them. I mean we have to see what is your ovarian reserve. If you can have a good number of oocytes, you can try, but the possibilities to get pregnant are very low. In your case, I would use the PDT-A to study the chromosomal abnormalities in those embryos, and the thing is that we have different possibilities. After the oocytes retrieval, we need to have good quality embryos, after that, we need to perform the biopsy PGT-A, so pre-implantation genetic diagnosis and see which embryos are normal or which ones are abnormal. The first possibility is if we analyze 3-4 embryos if none of them is normal, we cannot have an embryo transfer. The second possibility is more common, we will analyze the embryos, and the possibility to have some normal embryos is very low too, and if so, we’ll transfer a normal embryo.

Yes, I mean you have them there, so you have to try even though if they were frozen with an old technique, you should try and you see what you have. I mean you don’t lose anything trying to do it.

The transport shouldn’t affect the quality of those embryos or the possibility of those embryos to implant. If we’re talking about warming, defrosting procedure, we’re talking about different things. You have to make sure that in that clinic, they use the same protocol or even the same media because we have a lot of different media from different brands. You have to make sure that they know how to use that procedure in that clinic because that could harm the embryos for sure. With the transfer, I don’t see any problem because if you have a good tank for transport and you have liquid nitrogen inside, this shouldn’t be a problem.

I mean we’re using different brands, every media has a different protocol. If you bring your embryos to my clinic, if I don’t use that media, I’m not sure if I’m going to be able to do it correctly because of the different protocol.

This is more of a question for the gynaecologists, but as far as I know, there is no risk for ovarian cancer. We normally use the amount of hormones that are not too high. In the past, it used to be higher, but now it’s much lower, and I wouldn’t worry about it.

This is a difficult question to answer because sometimes you only need 1 egg you know with that egg, you have a really good quality embryo, and you don’t need anything else. Sometimes, you need more depending on the quality of the eggs and then the resulting embryo. It’s not something that I can really answer. Sometimes, even younger patients with 20 oocytes, they didn’t achieve the pregnancy. In general, a good number of eggs it would be 12, that’s a good number, in general for all the patients. We always aim for a good quality embryo, not a good number of eggs.

The devices that we use for vitrification are not really like in sperm, they have like a plastic at the end, where we place the embryos, and then we put it right away in liquid nitrogen. So they’re not in the straws like the sperm. The way we do it nowadays, so with vitrification, the results are better because you’re putting the embryos in contact with the nitrogen.

This is something that we normally do. The thing is it cannot be transported by a private person, it has to be done between clinics. They have to collaborate with this. The only thing you have to do is to go to that clinic and say that you want to take my embryos and I want my embryo to be transferred to another clinic. You have to sign the consent for that and then once you have signed, we talked to each other, and we’re talking between labs and try to organize the transport. This is something that we do quite regularly so they should collaborate for sure. It doesn’t make sense that they are collaborating with this.