Hello everybody, I'm Dominique De Ziegler, I work at Hôpital Foch in Surin, near Paris. And before we start this great Journal Club Global, let me introduce to you our new media editor. Now you understand that the Fothillian Sterility will have a new team starting July 1st, and in the case of media editing, well, the words have changed, what used to be new media has become simply media editor.
And the person I want to introduce to you is Mika J. Hill, who is the new media editor for Fothillian Sterility. Welcome, Mika, we're so happy to have you. Thank you, Dom.
It's a pleasure to do this, and I'm excited to continue this role with the Journal Clubs and all the media efforts with Fothillian Sterility. I also want to introduce Pietro Bortoletto from New York. He is replacing my old position as the Interactive Associate-in-Chief, so you'll be seeing him all over Twitter, Instagram, Facebook, and these Journal Clubs, so we're excited to be here.
We have a great topic today of pre-implantation genetic testing for aneuploid, can non-invasive testing based on spent media analysis replace classic trophectoderm biopsy? So Dom, who are our discussants on the pro and the con side today? Well, we have two discussants. This is going to be a heated discussion, I believe, such to a point that we actually are going to have in a little while a poll, and one at the end of the presentation. We have two discussants.
Ladies first, Carmen Rubio from Genomics in Spain is going to introduce the non-invasive aneuploidy testing, and she will be followed by Dr. Getea, who is the Clinical Director of the program at FOSH in the Department of Dr. UB, and he will present the opposite view. I have to say that Dr. Petya was well-trained. He has spent a research fellowship in Dr. Scott's office.
So we're going to have the two positions presented. Carmen, go ahead. Okay.
Thank you very much. So I will try to summarize in four slides the four questions that appear in the fertility battle issue, trying to recapitulate Catherine's opinion and my opinion, too, and then let's start discussion after that. So if you can share the slides, please.
Okay. This is the first question that we have in the fertility battle. It's about how reliable is embryonic cell-free DNA compared to trophectomyopsy.
So in this section, we were talking about the previous studies and the concordance rates found. First is the informativity rate, that there has been a wide variety of different informativity rates reported in the different studies, ranging between 80 percent and 100 percent. Later on in the discussion, for sure, we can comment about what are the factors that impact in the informativity rates.
But once we detect DNA in the media, the concordance rate with trophectomyopsy can be as high as 89 percent, with inner cell mass biopsies as high as 84.5 percent. And in this study from our group, we had similar concordance rate of the media and the trophectomyopsy with the inner cell mass, very, very comparable in a subset of samples. And the concordance rate with whole blastocysts that appear in some papers can be as high as 93.8 percent.
So in our experience, for fresh blastocysts without any previous vitrification or any previous manipulation, Day6 looks better in terms of higher informativity and higher concordance rate. When I talk about concordance rate, it's like ploidy concordance rate, it's not exactly the same as ploidy in the two samples, in the trophectoderm or the media, it's just if the embryo is abnormal and the media is abnormal too. And the main risk that we are facing is the contamination from cumulus cells that should be properly washed during embryo development to avoid the contamination with the DNA.
And also we have to be aware that environmental DNA can affect this. So we have to work in proper conditions. From the Katherine Rakowski opinion, sorry, can we go to the, OK, so on the right hand we have a table from Katherine Rakowski and she was comparing the results of these cases in which the embryos were previously vitrified and in this table she was summarizing the result of some papers, four papers, in which the media was collecting from Day3 and at different stages to Day6 or Day7 and the comparison with the whole blastocyst was showing very nice results.
In this comparison that Katherine did, the concordance rate, as you can see here, is as high as 90% for the non-invasive compared to 84% in the invasive and the main difference was in the false positive rate with lower false positive rate in the non-invasive. Katherine also presented in the paper a comparison in embryos that were cultured for one day from Day5 to Day6 or Day7 and in this subset of cases the concordance rates were even higher and showing significant differences with the invasive PGTA. So, high accuracy and reliability was supported by the comments of Katherine.
OK, now next slide, please. So the second question was if the embryo cell-free DNA is related to self-correction and or apoptosis. And I think this is the question that maybe we have more different opinions.
My point of view is that we don't really know the origin of the mechanisms for which the embryos release this DNA. The first idea is always to think that this is apoptosis because we compare the results that we obtain with the results of the non-invasive prenatal testing and at the very beginning we were with the same idea that maybe it should be apoptosis, but the truth is that the quality of the DNA that we observe is giving us very nice NGS results. So it's difficult, it's hard to think that this is degraded DNA or necrotic or apoptotic DNA.
That's the truth. Also, we observe very high concordance with trophectomyopsies, inert cell mass and with cold blastocysts. So if we have such a high concordance rate, it should not be because there is a self-correction mechanism because if not, the concordance would have not been so good.
Also, in one of our studies, we observed that low-quality blastocysts and embryos with an aneuploidy, they had the same concentration, the same quantity of cell-free DNA in the media before amplification and after amplification. So we don't think that aneuploid embryos secrete more DNA than good-quality embryos, at least in our hands when we are talking mainly with, working with basic blastocysts. On the other hand, Katherine has been commenting the results in the Murin model and in the Murin model, we all know this nice paper in which the frequency of apoptosis in inert cell mass of aneuploid cells was higher compared to the apoptosis in euploid embryos.
So let's see, because the Murin model is pretty different to the human model and in this Murin model, the aneuploidies were induced aneuploidies, they were not physiological aneuploidies and we know that in the Murin model, we don't have a high aneuploidy risk in mouse embryos. So I don't know if all the conclusions that we reach from the Murin model can be translated into the humans. But the truth is that the only properly designed study that we have is this one in the Murin model.
And also Katherine was commenting that in the blastocellic fluid, it was described that there are two, the DNA, when we analyse it, it shows two peaks and the dominant peak is of 160-220 base pairs and that is the similar size to the fetal DNA coming from the trophoblast. So I was trying to put together the two ideas and also we have been talking with Luca Giannaroli and he also thinks that the DNA in the blastocellic fluid can be from an apoptotic origin and he observed that each sample has a higher number of aneuploid chromosomes in the blastocellic fluid. We were testing this because we are working also, Luca Giannaroli is involved also in one of our RCT studies.
And the truth is that when we were checking the mean number of abnormal chromosomes in the media compared to the mean number in the trophoctone biopsies, it was very similar. So we can comment a little later more about this. And next slide, please.
So the third questions are, what are the reasons that the non-invasive model will prevail over a non-invasive model? And I think we all agree with this, that if we can find a non-invasive technology to do the aneuploidy testing in the embryos, that will be fantastic. We will not need to have highly trained personnel, lower cost, lower impact in the embryos. And what I think both of us, Catherine and me, we were highlighting these aspects.
Also that the RCTs with PGTA, Catherine was commenting, they show the benefit in patients ageing between 35 to 40 years, patients of an advanced maternal age, and still we need more studies confirming that the results can be good for any patient, despite we are applying PGTA and we all feel very comfortable with this and the non-selection of studies by Richard Scott group are very clarifying about the impact and the benefit of PGTA. So the non-invasive PGTA, we need to run away before substituting the PGTA. I think we need a way to think that non-invasive can substitute PGTA, but we can offer the non-invasive now with the studies we have as a prioritisation model and we think that as a biomarker to help to select the embryos for transfer can be very helpful, but not a dichotomic strategy, not transfer, not transfer, just to help to prioritise the embryo for transfer.
For sure, with automation, the automation is coming to all the IVF procedures and for sure is going to be also being applied to the fact that we can automatically wash the embryos and avoid contamination. So we think that once we can solve these different methodological problems and once we can also work with the OFINIs, the randomised control trials and the non-selection trials that we are doing, maybe we can have the answer if this can substitute or not PGTA. But at the current stage, we think that it can be used as a biomarker, not to substitute the PGTA, but to be offered to patients that they do not desire PGTA or as an alternative strategy for young patients in which the benefit of the LCTs has not been shown so clearly.
Next slide, please, last one. So what additional evidence is needed to support the probe? So we think that with the concordance studies we have done and with the subset of clinical data we have, we can offer this for clinical application, as I mentioned, as a prioritisation test. For sure, we need more studies with larger sample size and it's very important that the results can be reproduced in different laboratories.
So this will give us the assurance that the technology can be applied in any IVF lab and any genetic labs. But at the point, if there is a genetic lab, an IVF lab that has been working with a properly validated technique and the results are good, we think it can be applied now for this prioritisation system and to decide whether this will substitute or not it as a diagnosis test in the future to PGTA. For sure, we need more ongoing studies and there are already ongoing studies, randomised control trial and non-selection studies.
So I think we will agree in this part. So that's all I wanted to comment. Thank you, Carmen.
This was very nicely put, very concise as we expected it. Thank you very much. Muchas gracias.
Now, Dr. Pieter is going to show his way and his views on this. Paul. Well, thank you.
Thank you very much for having me here and allowing me to present my clinician point of view because, as you know, today the status in France is that PGTA is not legal at this point. So I will just try to take the evidence for sustaining my point of view. So PGTA in the traditional form or the newest form is, from my point of view, clinician's point of view, is a clinical embryo screening tool.
And this is to select out unemployed. This is the core of the subject because I think that some of the discussions were about unemployed. But actually, as the title says, the name of the test says, it's for selecting out unemployed, meaning that those embryos that are not employed have to be discarded.
So since the first clinical implantation of PGTA, technology has evolved. But today there is a mandatory requirement for validation, making sure that the technology behind that is validated. And this is a multi-step process.
And it has to prove specificity, sensitivity, safety, and all of this has to be proven in compliance with a proven safe clinical procedure, normal procedure, because otherwise the impact would be quite catastrophic. Next slide, please. So for the question, how reliable is embryo cell-free DNA versus the affected DNA, the representative of embryo chromosome constitution, well, by looking at the data that we have today, we know that by apoptosis, abnormal chromosome cells are eliminated.
So the DNA that is released into blastocell or the spread media culture is probably mostly abnormal. And this specimen cannot really affect the actual reproductive potential of the embryo itself. So discordances between the trophectoderm DNA and the sampling of whole embryo DNA are mostly attributed to maternal contamination, as mentioned by Carmen in the case of cell-free DNA, and embryonic mosaicism.
Specimen assessment is also compromised by the embryo cell correction that occurs quickly between day five and day seven or day eight of development. And this is very, I think this is very tricky as a problem. Maybe we are actually looking at the embryo at the wrong time.
And also, there are data showing that good embryos may shed fewer apoptotic cells and also have less DNA available in the spread media. So this will compromise the analytical process. And the spread media of those blastocysts with a higher reproductive potential will probably fail to amplify.
So as mentioned by Carmen before, concordance rates with trophectin biopsy were up to 89%, with ECM biopsies up to 84.5%, and with all blastocysts up to 93.8%. So maybe in reality, the mean level may be sufficient. But actually, clinically, we find to be not really clinically relevant because it has a high prevalence for intermediate results. So given that a useful technique requires 98% of samples to have sufficient DNA to provide analytic results, we find the cell-free DNA today to be unreliable.
Please, next slide. So what are the reasons why we think, or my opinion is that at this point in time, maybe in the future that will change, but at this point, the non-invasive model cannot really prevail over the invasive. So today, PGT-8 have shown enhanced safety without compromising the outcomes because since its implementation in clinics, it has increased implantation rates and decreased pregnancy losses.
PGT-8 technology has been validated with large prospective non-selection study, even though it has taken some time since its clinical implementation, but today we have the data showing that the predictive value for both euploid and aneuploid is quite correct. Random control trials have shown that the trophectin DNA-based selection actually improves the state implantation rates. And also very good data has acknowledged the safety of the trophectin biopsy, which was needed for the PGT-8, even though that requires training and validation.
So with this in mind, I think at this point in time, PGT-8 has a strong case. Also for the future, I think that it could also be impossible for the cell-free DNA to provide the same clinical value as the trophectin biopsies due to the fact that the embryo development is very dynamic. So you have, first of all, you have very small quantities of cell-free DNA and also you have a very rapid embryo cell correction that happens actually between day five and day seven.
Also recently published in FNS, there was a blind and non-selection study that evaluated the productive value of cell-free DNA. And this found to have, they found actually higher sustained implantation rate in the failed amplification group than those in the euploid group. And this has actually shown the high prevalence for intermediate results.
Cell-free DNA samples, as recently mentioned, are best obtained from spayed media culture that are from embryos culture between day four and day six. And this will mean not only extra manipulation, but also the necessity to continue culture to day six for all embryos, even if the optimal time of eutrophication would be at day five. So given that efficiency of more than 98% has already been clinically shown using trophectin in DNA, and that is being performed safely in many programs, it will be highly unlikely to accept anything less than that.
Next slide, please. So what are the additional evidence needed to support the case of cell-free DNA? So studies correlating cell-free DNA results with the trophectin in DNA are not sufficient because most of DNA analytic platforms have not been fully validated, even though it's been used in clinics for over 20 years now, but still. So cell-free DNA needs a large prospective blind and non-selection study to demonstrate the predictive value of both euploid and aneuploid results.
Also, it has to be followed by random control trials in order to report whether that selection based on cell-free DNA actually improve outcomes, otherwise it would be no use. Studies evaluating the impact of extended culture to day six for all embryos are required because this is what cell-free DNA needs to be accurate. And also, given the data that has been reported that PGTA trophectin bias increases preeclampsia, when we looked at the results in the paper, we have shown there is a little, let's say, substantial bias, given that most of the patients that didn't have PGTA were actually transferred in a spontaneous cycle.
And we all know that preeclampsia and hypertension conditions are something which are closely related to the frozen embryo transfer in a substituted cycle. So this really is important to be proven. Next slide, please.
So many technical questions require an answer, and this will be my last slide. So we all hope for a non-invasive PGTA. We all hope for that.
It's just that we are concerned to do no harm because this is what we want. We want to provide better results, and we have to stay away from doing harm. And new things, sometimes untested things, can be actually harmful.
So in order to make sure that the non-invasive will have a correct clinical implementation, several questions have to be answered. So what type of amplification should we use? Is it necessary to sample the blastocyst fluid or only the spent media? What is the best timing for the sample collection? Also, as mentioned, not all embryos are in the development stage at the same time. Does this really mean that following these embryos throughout day five and collect load samples at multiple times for each patient? I mean, if that would be the case, automatization or simplification of lab work would be highly challenging.
Also, how much volume should embryos be culturing? Because let's say people can claim that some platforms or technologies for non-invasive use too much volume of the medium culture. So this really has to be clarified and validated. Also, for that validation to happen, large well-designed non-selection prospective studies are really needed to prove the safety and efficacy of these techniques in the normal clinical process, because doing extended culture to day six for all embryos, even for those who don't need it, it's not a really normal clinical process.
Also, I think and maybe some of my clinical colleagues think that any early clinical implementation without answering all the technical questions mentioned would lead to catastrophic consequences, as we have seen recently in Australia, where they have maybe too soon accepted and implemented clinically a non-invasive PGT-A technique. Thank you. Paul, Mika, he's taking over.
All right. Thank you, Dom. Thank you, Carmen and Paul, for that fantastic introduction.
There's going to be a lot for us to unpack with our expert panelists there. Just a few quick things before we get to that. We've had some of these authors talk about the recent non-selection study that came from Brett Hansen and Dr. Scott's group.
That was in FMS Journal Club Global a few months ago. So if you want to log into First Start, you can read that. It definitely has some bearing on this discussion.
For our audience, we have over 600 people that registered to watch this, and we have several hundred live right now on. If you look on the right, you can see the Fertile Battle PDF. Fertility and Sterility is providing that to you for free.
So you can read the written arguments that were published by our group that is here today. Also, if you have questions for our experts from the audience, you can type them into the chat section, and Pietro will be curating those. You can also tweet us out at First Start, and we're monitoring the Twitter account and can also answer those questions there.
So before I introduce our experts to unpack all this, Thea, if we could please launch our audience poll. So audience, you've heard the opening debates on the pros and the cons. So we want to know what you think, and then we're going to ask you again at the end after we hash this debate out.
So will non-invasive PGT-A and spent culture media substitute for trophectoderm biopsy? Yes or no? And we'll close that out in about 30 seconds. And Thea, once you close it out, you can go ahead and publish those results so we can see it, and then we'll go back to our cameras. All right.
So we're very split. This is going to be interesting. Almost 50-50, probably a statistical tie.
Okay. So if we can go back to the cameras, I'm going to introduce our expert panelists who need no introduction. This is really a who's who of research on this topic.
So we have Dr. Catherine Rakowski, who is a university consultant of OBGYN and gynecology and reproductive medicine at Hospital Fauche. She is joining us from France. She is professor emeritus at Harvard, and of course, the past president of the American Society for Reproductive Medicine.
So welcome, Catherine. Thank you for joining us from Paris. We have Laura Rinzi.
She's clinical senior embryologist and IVF director. She's an adjunct professor in biotechnology and ART at University of Urbino in Italy, and the scientific director of General Life International Reproductive Medicine Network, which is all over Europe. And then last but not least, we have Dr. Richard Scott, founding partner of EVRMA Global, additionally the clinical director of andrology, the clinical director of the practice, clinical director of andrology and endocrinology laboratory director, embryology director at RMA New Jersey.
And I think between these three expert panelists, we have six or 700 publications, many of them on this topic. So Catherine, we'll just go in the order in which we introduced everyone. In past debates on this topic for trophectin or PGT, we've had you on the con side, and now on this one, we have you on the pro side.
So tell us what your thoughts were and why you took that stance to this debate. Oh, I think we can't hear you. Thank you very much, Micah.
And it's a real pleasure to participate in this discussion. It's going to be very interesting, as you said, to see what happens at the end of the discussion in terms of the polling. So I think we all would agree that this is a very tricky discussion to have.
The question posed is extremely awkward. And I think it's particularly awkward because as a field, we've not been good at doing the correct validation work before putting any technology into the field. And that's not to say at all that we shouldn't do it for this particular technology, technology non-invasive PGTA.
I think it's fair to say that there is a sufficient number of studies that have been now performed that demonstrate the presence of cell-free DNA in spectrum culture media. And the question really is whether the cell-free DNA can be reliably amplified. And if it can be, do the results represent the ploidy of the NSL mass? I mean, those are the two, I think, real crux of the issue questions that we need to address.
So other than the recently published paper from Richard Scott, Dr. Scott's group, first author, Brent Hansen, as was mentioned, all previous studies, to my knowledge, have used either vitrified blastocysts and or blastocysts that were previously biopsied. And there is an argument that can be made that either of those interventions might change the way that there is leakage of cell-free DNA from the embryo, particularly with a previous biopsy. I would offend the study that we published in PNAS, the first author of which was Lei Huang, by simply saying that, as we all know, it's very difficult to do these studies with clinical material.
And this was the first of several studies that we planned in order to, first of all, to ask, can you actually reliably detect cell-free DNA in the culture media despite the embryo being previously biopsied? And I think it is fair to say, and we haven't the data yet, that perhaps with assisted hatching on day three, that might be sufficient to actually be able to amplify the DNA more reliably. I do note, though, that Hansen's study did do that assisted hatching on day three, and I'm sure we'll be addressing why the amplification rates were very much lower than has previously been published. So, collectively, if we look at the data comparing the spent culture media to the whole embryo and to affect the biopsy with the whole embryo, as Carmen mentioned, one finds that there is a really compelling data that there is a lower false positive rate and higher positive predictive value in concordance with the non-invasive PGTA versus the invasive.
I would also mention that there really are several disadvantages with trophectoderm biopsy. Obviously, there's this mosaicism issue. It affects a relatively small percentage of embryos, probably less than 5%.
But I think the issue that we've not carefully really considered is we are forced to discard embryos that don't meet the criteria for biopsy when we do trophectoderm biopsy. And we all know from the morphological evaluation work that's been done over the decades, that morphological evaluation is not perfect by any means. And by discarding embryos based on the fact that they don't meet criteria for biopsy, I think it's not responsible.
Because some of those could perhaps have made healthy babies. And then, as was mentioned by Paul Papieta, there is emerging data showing that there is an increased risk of preeclampsia and hypertension associated with trophectoderm biopsy. I commend Richard Scott's group.
They did the early work showing that there was no difference in gestational age and weight of the babies born from trophectoderm biopsy versus non-biopsied embryos. However, we're now actually starting to see data, because more studies are being done, that actually suggest there may be some risks to the mother from trophectoderm biopsy. And we must remember that hypertension is associated with placental disorders.
And of course, the placenta arises from the cytotrophic blast. So, I mean, there is perhaps the real issue that trophectoderm biopsy does increase the risk of these serious obstetrical conditions in the mother. So, just in closing, I think it's clear that we need to work much more diligently to improve non-invasive PGTA.
It should not be used clinically in the field. This is my position. The work has not been done for it to be used in the field.
But by the way, the work wasn't done with trophectoderm biopsy really before it was put in the field, or with cleavage stage biopsy. But aside from that, standardizing the methodology, as was mentioned, we need to understand what is the best volume of culture media? What is the best day to collect the culture media? There are all sorts of issues with actually collecting the media. How is the media collected? If the embryo is sitting in the middle of a micro drop, there's going to be more concentration of cell-free DNA immediately around it than there would be at the periphery of the drop.
So, how does this all play into whether one can actually reliably amplify the cell-free DNA or not? So, that's my position. I've covered a fair amount of stuff, but thank you for the opportunity. Catherine, a quick follow-up before I go on to Laura.
So, you're on the con side, but you're also, or the pro side, but you're also giving a lot of cons. So, I guess, would your standpoint be that this is something that is not ready for clinical usage and to be charging patients for, but needs more evidence, and you just think that the future research will lead us to have this as the way we do PGT? A hundred percent, Micah. We don't have the data yet to be able to charge patients for this technology, just like we didn't have the data to charge patients for time-lapse imaging for the metabolomic work, and indeed for the cell over cleavage stage biopsy, where, by the way, there were lawsuits with that as well.
You know, we've just not been good as specialists in the field of actually doing the correct work before actually putting these technologies into the clinical field, and there are many reasons for that. Yeah, I'll stop there. I agree with that point.
I think it's an important one that can't be overstated. So, Laura, give us your opinion as an expert on this topic, please. Thank you for this invitation.
It's such a nice webinar. I'm so happy to be participating. I'm learning a lot, and I have a lot of food.
So, I will try to summarize. So, I will start from a completely different point of view, which is the assumption that one technique should replace another. I don't think that in this field, we will have a single technology able to represent the quality, the complexity of an embryo.
So, each technology is just adding something, and by combining them, we can really obtain comprehensive information about the embryo. I don't think that we should exclude morphology because we are applying genetic testing. I don't think that if we introduce non-invasive genetic testing, it means that we cannot use invasive genetic testing in case we have no results or in case we have a particular case.
So, these are opportunities that technology is giving us. And because I am a scientist, and I believe in science, I'm sure that the technology will evolve, and we have to be open to accept the new possibilities that will arise in our field. So, about today, the assumption to say that we have 98 percent concordance when we do trophectomy and biopsy.
This is true in Dr. Scott's lab. It's true in some of the labs in the world, but it's not true everywhere. To think that what has been published by the leaders group is reproduced in every single lab is also a mistake.
So, we don't have to think that in all the labs, we have a perfect setting for genetic testing with trophectomy and biopsy. And it's easy to prove that because there are some centers that are reporting five percent mosaic, some other 30, 40, 50. What happens to these 30, 40, 50 percent embryos that are considered mosaic? I mean, the biology is the same everywhere.
So, the interpretation of the genetic testing may be very different, and we are maybe losing embryos by overestimating or misinterpreting, making misinterpretation of the data. So, to say that trophectomy and biopsy is perfect everywhere, and now we are going to change to an imperfect technology, for me, it's not a good assumption. So, also trophectomy and biopsy, and especially the genetic interpretation of the output should be standardized.
And what is lacking in our field is not really the validation, but it's the standardization and the homogeneity between labs and centers, especially when we combine different expertise, which is the gynecologists, the embryologists, plus the geneticists now. So, whatever is helping, standardization, reproducibility, lower manipulation means more standard results, because each time there is a manual manipulation, we are adding variability to our test. We have to be very, very positive, accepting this kind of new approaches, because it means that maybe we're not going to reach the top standard, but we are going to reach a standard which is acceptable everywhere.
And the last point I would like to raise is the idea that when we have a positivity in the test, in the genetic test, we discard the embryo. So, this is not the case in my country, I cannot discard any embryo, or even one that is affected by a genetic disease, so we keep the embryo frozen. And this is also the idea that we have when we may think about introducing non-invasive PGD.
The idea is not to discard the embryo if there is a positive output, but is maybe to give a second chance with a trophectomy and biopsy, maybe just use the prioritization as it is done for morphology. Nobody is complaining that a bad embryo morphologically is transferred. So, combination of technology, standardization, homogeneity in the way we make the interpretation, this is the way to go.
More than saying we need randomized controlled trials, because randomized controlled trials are done in supersetting, but maybe are not reproducible. So, for me, the real validity of a technology is when it is the same, with the same results in the majority of the lab. So, Laura, I appreciated your comments on the nuance of not having it be a dichotomous debate, but maybe both have some role and could potentially be complementary.
So, modifying the question to Catherine, do you think that is something that is clinically useful today? Should we implement that clinically as an adjuvant to help us select the best embryo? And if not, do you think it is something that will be a viable technology in the future to have that role? So, I think that if patients are counseled appropriately, that the data that is going to be acquired with a non-invasive approach is actually going to be used in a responsible way to advance the science, then absolutely, it can be done. Because it's not invasive, it does not harm the embryo as long as you're not forced to culture the embryo for longer. We can discuss that.
And there is data, as Carmen has pointed out, that shows that you're not harming the embryo by keeping it in culture until day six or seven, if it has become a very good blastocyst on day five. I would actually, I would question that. I mean, I've always taken the view, and people have probably heard me at the podium say this, that the less you tamper with embryos, the better, the shorter the time you keep them in culture, the better.
The in vitro system is entirely different from the in vivo environment. And although, you know, we're very cavalier in saying, well, the culture systems are so great today and we're not doing any harm to the embryos. Guess what? We really actually don't know.
And so, you know, I would say that patients need to be counseled and the data that's acquired can add to the information to balance the science. And Laura, do you agree? You think this will be a technology that we'll be using 10 years from now, five years from now in the lab? I'm sure about it. It's a little bit the same story of non-invasive prenatal diagnosis.
It was something that 10 years ago was a dream and today is a reality. So I truly believe that science is so fast evolving that we will get what we are expecting from this technology very soon. Great.
So, Richard, I'm fascinated to hear your thoughts. You're a mandatory speaker on the pro PDTA trophectoderm biopsy side for a decade now. And here we have you on the con side for NIPDTA.
So why did you take that position with this topic? Thank you so much, Micah, and everyone for the opportunity to be here and participate in what is already, for me, a fascinating discussion of this topic. And there are a few points where we're going to disagree, but I think there's actually a great degree of concurrence amongst the people who are commenting on these things. And I was making notes as to what Catherine said and what Laura said, and I could fully support their position on many things.
But I will point out just a few things where maybe if I look hard, I can try to find a few differences. One of which is that I think it's important to remember that PGTA is different than PGTM and SR. With PGTM and SR, we need a genetic diagnosis, right? But with PGTA, all we're trying to do is separate embryos which are truly reproductively competent from those which are not. You're never going to validate a PGTA assay by saying it's correlated with the ICM or other trophectoderm biopsies.
Because really, in the end, that's not clinically sufficient. I'm not saying it's unimportant. And as a part of validating and standardizing these assays, it is important.
The researchers need to do that, and we need to understand the biology. But clinically, it's just whether or not if you say the embryo is going to implant, that it will. And really, most often, if you're using it as its own sole marker, if you say it's not going to implant, because there's so many reasons embryos fail, not for genetics, that you're never going to get perfect predictive value out of just one parameter, as Katherine and Laura both said very elegantly, and I would agree.
But the ones that are aneuploid, no matter what, should not be making babies. And I agree with that. So again, you're not going to validate these things.
And they probably shouldn't be showing up in the clinic because you can correlate it with other biopsies. I think the most fascinating issue to discuss here is whether or not noninvasive PGT, as done today, is safe and whether it brings no risk. And Katherine already beat me to the punch and brought up the issue.
And I'm smiling very big, Katherine, because it's an excellent point you made. But the reality is that in our laboratory, and we have, through our system, many hundreds of thousands of even millions of embryos. If you take an embryo that's expanded on day five, we tried for logistical reasons to move everything to the morning of day six freezing.
And I have to tell you, the ones that were ready on day five, if you go to day six, implantation rates decline. And that's an internal QA project for us. We never really did that as a prospective study, but the data points go into the many, many hundreds of thousands.
And so I don't believe that extending culture beyond that which is optimal for the embryo was good. And that's what Katherine said, and I'm just agreeing, Katherine, I'm just agreeing. And I don't think the data and the literature are compelling, are sufficiently powered to be compelling just yet.
Her PNS paper, which I consider to be a landmark early contribution and could talk for a long time about many positive things, does bring the qualifier of warm blastocysts that were already at that stage, which now you're going to lose some cells and the DNA may end up in the media from warming, as you know, and then they were cultured for up to another day. Again, giving more time for more DNA from potentially lost cells. We're never going to do that clinically.
And so while it was an important proof of concept, it needed to be done. Extremely valuable contribution. The reality is it's not a clinical correlate.
Also comparing whole embryos is not a really good clinical correlate. And so I don't know that it's safer as it's done now. Katherine brought up the issue of lower amplification rates.
You know, quite frankly, the higher the quality of the embryos, the lower the amplification rate. And so we're not using discarded embryos. We're not using ones that have been through the cryoprocessing.
We're not using one that have had far extended culture beyond the optimal time. And so you would expect lower rates because there's going to be a lot less DNA there. And it is still disturbing that the highest implantation rates are in the embryos that don't amplify, which is a problem because people are going to want to use the data if they get it.
That's even if you're using it as an adjunct to add on to classic PGTA using trophectoderm biopsy. And so I think that all of us would love to have non-invasive PGTA. We still have important biologic questions, which is in a highly and a high quality blast culture for the appropriate amount of time to optimize its outcome.
Is there sufficient DNA to reliably provide an answer to provide direction? I agree with Katherine that too many embryos are being discarded from PGTA. I could not agree more emphatically. But some of that is because the validation and standardization studies that my colleagues have referred to have not been done.
I don't think there are huge differences between laboratories. We do screening for 43 laboratories. And I have to tell you, we find very little difference in mosaicisms or segmentals.
I don't think it's the labs because the biology, just as they said, does not change. What it really is, is the assays. And the assays are less reproducible and reliable.
So that's an analytical problem, not a biologic problem. And it may be solvable one way or another. So I will close just by making a couple of quick comments is that we have absolutely serious reasons to be concerned that NIPGT, if you're going to be able to get a reliable result, is less safe.
And we certainly need the same kind of large prospective blindness studies to prove that it is not less safe and can still provide a reliable result. Its ability to select above and beyond, and this is for Carmen, again just a landmark study and one of the original ones. And there's so many positive things to say.
I don't want to lose focus on the positives. But the reality is if you look at the implantation rates, the euploid-euploids implanted sustained implantation rates in the 40s. And the euploid-aneuploids in the high teens.
You put them together, because if you weren't doing the NIPGT, their overall euploidy implantation rate would have been in the low 30s, which is roughly half what their own program produces if you look on their website. So these were somehow very poor prognosis cases, or very poor prognosis embryos, or they've done something to make them poor prognosis embryos based on their own data from their own centers using their own assay. And so I don't think we know yet that it's safer.
And then all I'm going to do in the end is agree with Catherine, or almost agree with Catherine, which is say, you know, we need to do these studies. I think this technology is not going away. I think we need to know more about the biology.
Its ultimate application will be based on whether there's enough DNA that's representative in the media with high-quality embryos. And we need to figure that out. And some of the people on this call are the ones who are going to figure it out, which is excellent.
Should it be used clinically yet? That's probably my greatest outlier point is that I don't believe it's ready to be used even as an adjunct. As long as the highest implantation rates are the ones where you don't get a result, I think you're going to be, you stand to be doing lesser, you're going to provide lesser outcomes to your patients because you're going to want to use the information that you have. It's just too tempting.
But with that, I will stop and I will look forward to everyone else's comments. This is great. We have a fantastic debate, Mika.
And I would like to ask a question to Paul and maybe let him ask questions. There's an issue of risk. And on the battlefield as elsewhere, the risk does not always come from where you expect it.
And we actually read this article with Paul on the risk of preeclampsia in relation with BGTA. And what we found analyzing the data in details is that there were an explanation for that. There were much more frozen embryo transfer in the group that had the preeclampsia.
Could you comment on this, Paul? Yes. So as mentioned in the presentation, actually, we also were surprised about the results. And this is why we looked into it.
And it took some time. But actually, when we looked at it, and this is why I showed the slides, is that actually in the group of BGTA, the transfer were actually the majority and even more as a number compared to those with no BGTA were transferring substituted cycles, which is known to be a factor predisposing for preeclampsia and hypertension factor. So I think... We don't know why.
We don't know why. Yeah, that's correct. We don't know why.
And also, we are doing every day frozen embryo transfers with substituted cycles. And we are always looking for ways to prevent that and maybe think about spontaneous cycles, natural cycles, and so forth. But the reality is that that paper, even though it's actually a good paper, but still there is a bias to that.
And I think that claiming that professional biopsy based on the paper, it's misleading, actually. Surely, we're going to need more data. But I think only on that data, it's highly misleading.
Catherine, I think Catherine raised her hand. Yeah, I just wanted to make... Agree with Paul on the preeclampsia issue, but the hypertension paper actually was correctly controlled in the two groups. And there, there was a threefold increased risk of hypertension in the trifecta and biopsy group compared with the control non-biopsy group.
However, the numbers are small. And this is why I really feel we just need a lot more data, a lot more rigorously done studies to really answer these questions. We don't know.
But I have to admit, as a person who was trained as a developmental biologist, reproductive physiologist person, I've always just been concerned about taking cells from the trophectoderm. And for all the reasons that we know, we now know, if you think of the morphological evaluation, that the trophectoderm trumps the inner cell mass quality in terms of being the criteria for selecting embryos. So, that's my two cents about the hypertension paper.
We have our live audience that's been sending us questions. So, before we wrap up, I want to make sure that they're heard. So, Pietro, what's the best question you had from our audience that you want to give to our expert panelists? Thank you, Mike.
I have two questions from the audience that I think we would love to hear the panel's thoughts on. The first one, specifically for Dr. Rakowski, given her expertise in the embryology lab and as a developmental biologist, the audience wants to know teleologically, why is that cell-free DNA there? Why is it in the media? Does it have a role in communicating with endometrium to facilitate implantation and decidualization? Or is it just cell waste that we're having to pick up? And if we're removing it, could it have detrimental impact for that embryo's reproductive potential? That's an excellent question. And honestly, I don't think we have the data yet to really be able to answer it conclusively one way or the other.
Is it to do with self-correction of the embryo? Is it to do with abnormal or degenerating DNA that is actually just being leached out of the embryo? I can't answer the question any more than, we wrote in the Fertile Battle and we discussed tonight, unfortunately, I wish I could. If I could just very quickly make one other point about self-correction, because we've talked about self-correction of the embryo and how leaching of the DNA might actually result in self-correction, and that this might be an argument for not doing cell-free DNA. But if the embryo is undergoing self-correction right the way through early development, at least till implantation, then it doesn't really matter whether you're doing trifecta and biopsy or non-invasive PGTA, you're still going to run the risks of getting an unreliable result compared with the inner cell mass.
And I know the inner cell mass is what we should be concerned about here, not the whole embryo, the ICF. So I would just make the point that for both approaches, there is a limitation that we're just taking one snapshot in time to get the sample for analysis. And I firmly believe that if we can really develop the microfluidic systems for culturing embryos and collect the media right the way through, if we want to go to the blastocyst stage, we might actually be in a better position to get a more reliable result of the ICF.
And I have one more quick question for Dr. Rubio from the audience before I turn it back over to Dominic and Micah. Dr. Rubio, one of our members in the audience wants to know if non-invasive PGT was better than invasive PGT, why use it as a priority selection tool and not just use it to select against aneuploidy? OK, thank you. Our position now is that non-invasive can be as good as PGTA.
I'm not in the position of saying it's better. I can say it can be as good as PGTA is performing proper conditions. And the experience we have now is the comparison of the media with the inner cell mass with similar results to the trophoctome biopsy.
So this is one of the data we have. The other data that we have is clinical data, not published because it's just the beginning of the application of this in some IVF laboratories. And there is an abstract accepted in error.
It's going to be a poster in which one of the labs working with us, they have compared the results in a period of time of patients below 38 years of age and ovum donation patients. And they were comparing the cases in which they were doing PGTA, the cases in which they were doing non-invasive with the analysis of the media on day 6. PGTA was day 5 or day 6 biopsy, according to the regular embryo development, non-invasive only on day 6 and regular IVF-XC cycles, again, with transfer day 5, day 6. And PGTA and non-invasive behave very similarly in terms of clinical outcomes. So very good ongoing implantation rate.
And they have, I think, was 12 percent, 12 points higher ongoing pregnancy rate compared to regular IVF-XC. So the experience we have now is that it can be as good as PGTA. And what we were commenting, it can be a complement to PGTA for those patients that with poor embryo quality, patients that they don't want to go through embryo biopsy, small IVF labs without a laser and good prognosis patient, because we always have also the debate if PGTA should be preferred to good prognosis patient or not.
So maybe this is an additional tool, as Laura said, to combine with morphology, our irregular morphokinetic system, to combine, to improve the ongoing pregnancy rates in the first transfer. And what we have also from our first studies in collaboration with General Lab is that if in the first transfer we can avoid miscarriages by trying to transfer first a good embryo, I think this is a very good advance for the couple. So at least in the first transfer, the two first transfers, we can select the euploid embryos we are going to minimize or to decrease the miscarriage rate.
So this is the idea we have now with this experience we have collected. Great. Thank you.
So we're up against the clock. So Dom, I'm going to turn it over to you to go around the room and get our last statements from our experts. We might ask Thea to give us the poll to see whether we shifted the audience.
Audience, we have about 30 seconds before we close this poll out. Go ahead and let us know what you think after hearing the debate. And while we're waiting, before we close out, I'll just say the next Fertility and Sterility Journal Club Global will be 26 August.
We'll be having FNS Reviews, an article from them highlighted, being hosted by the group from Duke, as well as editor Anne Steiner and media editor Blake Evans. So join us August 26 for that. And I will say again, congratulations.
Oh, it hasn't changed very much. I will say again, congratulations to Mika and Pietro. Welcome on board.
We're going to have lots of funny and interesting journal clubs to come. Thank you all.
