Alright, good afternoon. Welcome to our scheduled debate, Non-Invasive Embryo Selection Techniques are Clinically Useful. This is a special debate because hopefully the idea is that this is being live streamed by Fertility and Sterility as part of the Fertility and Sterility Journal Club Global.
And my name is Dr. Alex Kwas, I'm the moderator. I am the division director at the University of Basel in Switzerland. And this is, I'm very honored to moderate this because it brings together two entities that are very near and dear to me.
The great Pacific Coast Reproductive Society meeting. If you haven't been, you should attend it. If you come once, then you will always come.
And then also the Fertility and Sterility Journal Club, which as a member of the Interactive Associates of Fertility and Sterility, I have been involved in. We have a fantastic panel today to discuss this topic. Dr. Paul Lin, Dr. Jason Franasiak, and Dr. Richard Scott, who I will introduce in a bit more detail in just a moment.
The expected learning outcomes are to identify the technical challenges associated with non-invasive PGTA, discuss the evidence for techniques evaluating spent culture media, discuss the evidence for time lapse imaging, and go a little bit into the role of AI. So, I don't know if this is going to work, but maybe we can do this. For the people who are attending online, they can maybe try to click if that's working.
But otherwise, we'll also have a show of hands. So the question is, in your opinion, which of the following holds the most promise for the non-invasive selection of embryos for transfer? A, non-invasive PGTA, B, evaluation of spent culture media, or C, time lapse imaging. If you had to pick one of these three.
So, show of hands who thinks that A holds the most promise. We have about maybe 30. Okay.
B, evaluation of spent culture media. I guess you'll learn that in this. We'll ask the question again at the end.
Okay, that wasn't that many. And then time lapse imaging. Okay.
So we have actually almost evenly split. Not everybody raised their hands, but we'll have that question again later. So, I've already introduced myself.
So the quest for non-invasive selection tools is ongoing. And so you can see publications in journals like Fertility and Sterility, basically in almost every issue. So now I'd like to introduce the debate panel that will actually debate that, because I'm just the moderator.
So I just wanted to introduce the topic. So Dr. Paul Lin is currently a physician in a busy private practice in Seattle, Seattle Reproductive Medicine, where he also serves as the medical director of the Seattle Reproductive Surgery Center. Dr. Jason Franasiak is an attending physician at RMA New Jersey, where he serves as lead physician and high-complexity laboratory director of the embryology and andrology labs at the Malton office.
And Dr. Richard Scott, I introduced him also this morning at the meeting and said he does not need an introduction, but I'll do it anyway. He's a board-certified reproductive endocrinologist of EVRMA and one of the founding partners of RMA New Jersey. He has published over 700 publications, and his research interests include, amongst other things, the non-invasive screening of embryonic reproductive competence, which is what we're discussing today.
So the structure that we have developed for this debate is that there will be a pro and a con section for the three topics of non-invasive PGTA, spent media omics, and time-lapse imaging. And the panelists have either voluntarily or involuntarily agreed to take the various con and pro positions, and so we'll see how that goes, and we'll see what you agree with the most. So let the debate begin.
And so our first debater is Dr. Jason Franasiak about debating the pro for non-invasive PGTA. So a great pleasure to be here today to be the pro non-invasive PGT panelist. In general, some of the things that I wanted to talk about with the benefits of non-invasive PGT is the potential for it to be more cost-effective, the fact that it requires less micromanipulation skills, and that it has the potential to be a lower risk to the embryos.
For PGT, genetic material has to be, of course, isolated. This is done via either blastomeres or trophectoderm. There is some good data, which has already been discussed here, talking about the fact that day three biopsy does harm the ability of the embryo to create a child.
Despite the evidence of impaired implantation, which can be as much as 39% relative reduction, the long-term health benefits of individuals is a bit sparse. Some studies have reported increased neurodegenerative disorders, higher body weight, and significant epigenetic modifications, and these are in mouse studies. The trophectoderm biopsy performed at day five or more post-fertilization removes five to ten trophectoderm cells, which can allow for better amplification and lower oleic dropout.
There's data from Teagues in 2021 and Scott in 2013 that trophectoderm biopsy does not harm the abilities, the embryo's ability to create a child. However, Neal et al. in 2017 showed that relative amounts of DNA content, which is a surrogate for the size of the embryo biopsy, does, in fact, have impacts on pregnancy outcomes.
The data only kind of encompasses the ability of the embryo to create a child and does not provide reassurance that the impact of the biopsy does not have impact on the fetal development or downstream effects on children. There's also substantial variation in clinical outcomes from PGT cycles in different clinics, and this may not be entirely explained by the patient population alone. The embryo biopsy techniques have never been fully standardized, and one could speculate that some of the interclinic and interbiopsy practitioner differences may be, in fact, due to divergent biopsy techniques.
Additionally, in order to obtain the genetic material, there are some additional costs which are associated with traditional PGT. There has to be a laser to breach the zona pellucida and remove the genetic material from the embryo. There has to be staff costs for highly trained embryologists.
There's the time spent performing the biopsy, and some of these costs may actually limit some of the clinic's abilities to offer this to their patients. And with the cost of genetic testing decreasing, the cost of obtaining the biopsy may actually be the most substantial part of the PGT as it would be performed with a biopsy and analysis of the trophectoderm. The discovery of DNA within the blastocelic fluid and within spent culture media has driven some significant interest in data surrounding the potential for noninvasive PGT.
Blastocentesis is already a routine task performed in the embryology lab as it can often be done at the time of vitrification. There are really kind of two requirements that we have to have. One of them is that you have to be able to isolate the DNA to analyze, and the second is that the DNA must be representative of the developing embryo.
In terms of isolating and analyzing the DNA, the amplification of blastocelic fluid DNA in several different studies has ranged from 35% to 88%. It is believed to be somewhat degraded, leading to higher allelic dropout, which could be problematic for PGTM cases in particular. Giannaroli in 2014 found fairly high concordance with ploidy between the blastocelic fluid and the trophectoderm of up to 97%.
That same group repeated the study with a larger group of embryos. This was Magli et al. in 2016.
They had good accordance rates with the trophectoderm biopsies of about 97%. The blastocelic fluid DNA amplification in that study was 82%. It is important to note that other groups, Capalbo et al.
in 2018 and Topler in 2015, reported much lower concordance rates. The discordance between these outcomes is not clear, and it could be attributed to mosaicism in the embryo. The embryo quality, as some of these embryos being studied were donated for research, and the PGT platform being utilized.
There is something to note that Magli et al. reported a significant learning curve when it came to the successful amplification of blastocelic fluid DNA, with 50% at the beginning of the study and 100% at the end of the study. The authors had hypothesized that the, quote unquote, tubing of the blastocelic fluid was a critical step, and that pipetting the blastocelic fluid immediately into cold PCR tubes with centrifugation was a potential factor with the improvement.
The shortening of the DNA in these blastocelic fluid aspirations is problematic, particularly when it comes to whole genome amplification techniques. The diagnostic efficacy may be improved with new whole genome amplification techniques designed to amplify smaller DNA fragments. So in some of the blastocelic fluid samples that do yield a result, oftentimes seem to have accurate representation.
The accurate representation of the blastocelic fluid with the DNA, again of note, does range from 2.9%, which is quite low in the Capalbo study in 2018, to 100% in a study published in 2017. In terms of spent culture media, the issue is that some of the spent culture media may indeed contain maternal DNA contamination. Amplification rates are much higher with the spent culture media with the WGA techniques.
Ranging from 81% to 100%. Capalbo et al. found higher rates of amplification in spent culture media than blastocelic fluid.
An interesting study in 2019 by Rubio et al. found that spent culture media and trophectoderm diagnoses, when the trophectoderm and spent culture media were concordant, pregnancy rates were higher and miscarriage rates were lower. The end in the study was a little bit too small to make predictions.
However, this indicates that perhaps spent culture media analysis may be additive in some way to trophectoderm biopsy. So in summary, the non-invasive PGT with blastocelic fluid or spent culture media is potentially more cost-effective. It certainly requires less micro-manipulation skills and has the potential to pose lower risks to the embryos.
Amplification issues do persist with both the blastocelic fluid and the spent culture media. A solution may be to utilize a novel amplification technology adapted to degraded DNA and allow for more sensitive DNA detection technologies utilizing next-generation sequencing, digital PCR, or pyro-sequencing. Also, interestingly, the non-invasive PGT may be potentially additive when it comes to traditional PGT.
Thank you. All right, we've got Dr. Scott next to argue against his former fellow. A clear example of when the student becomes the master.
So thank you, Jason. I have a couple of starting comments real quick, and then I'll try to stick to my five-minute time limit. One, I can't tell you how excited I was to have Kahn on a PGT topic with Rick Paulson in the audience so we could agree.
And then it broke my heart when they asked which technology was most likely to be useful, and he raised his hand for PGT, and we may end up on the opposite side again. But all things more seriously, I agree with 99% of what Dr. Franasiak just said. He summarized and quoted the literature very precisely and accurately, and it really provides a great oversight of where we are in this process.
One thing you didn't hear him say, though, was that it works. Did he actually say that more patients get pregnant or that there's data to support that? Because I don't think I heard that. And that is what today's debate is about.
And so to be honest with you, I'm a proponent for NIPGT. I just don't think it's ready yet. I think it has great potential, particularly as we learn more about it.
The blast to seal fluid stuff is so complicated. We've spent time in Italy. We've looked at all those techniques.
They are certainly not less invasive and less complex than just regular old PGT. And they're very difficult to do. And Magli's paper came out four years ago.
Where's the clinical study? Re Ipsilopiter. It speaks for itself. So the reality is that if you want to read about sort of the clinical correlates and where we have gotten with NIPGT, I would refer you to a review article written in JARG by Dr. Ballarest, Moosa Chamaki of Pacific Coast and ASRM was the second author on that paper.
And it really provides a very nice summary of what we know and where we are. And the reality is it's getting better. And there's information there that might be useful.
But the overall predictive values remain very low. Carmen Rubio, who was originally from our group's Spanish program and a friend and highly respected colleague, talked about another platform and published a couple years ago now. And in her paper, what you'll find if you look, it's published in FNS, what you'll find is that concurrence for ploidy and gender, gender is qualitative, is 84%.
So I've gotten beat up brutally over the years at debates with my esteemed colleague for a technique that has a positive predictive value for abnormal of 99%. So if 99% is not good enough, how are we going to live with 84%? Now, that study did find that if you had both positive trophectoderm and NIPGT, that they did better. And if they had abnormal, even if the T biopsy was normal, if they had an abnormal NIPGT result, that they had 16% implantation rates, quite low.
But it was undersized for any statistical comparison of any means and really needs to be studied prospectively. The overall sustained implantation rates in the whole study were quite low. And so the take-home message from those two studies are that work is being done, and it's meaningful work, and it should continue, but there's no data to support its use.
Now, the other paper that's received quite a bit of attention is the PNAS paper from Wong, where Dr. Rakowski, former president of the ACRM, was the senior author and certainly one of the distinguished investigators in our field. And they found higher correlations and higher predictive values comparing evaluation of the embryo, but they took the whole embryo. So the name of the game in PGT is starting material.
More is easier, less is harder. And so if you put the whole blast end, a day six but now cultured to day seven blast end, and you get all those cells, do you think that's easier or harder? That's easy. When you look at the spent media from them, their correlations were pretty accurate in the 90s, but we have not been able to reproduce that.
I showed you data this morning. I'll quote it again briefly in just a moment. We've not been able to reproduce that in the clinical world.
And the reason is this. The PNAS study was based on day six embryos. They were then vitrified.
So we know that when you vitrify embryos, you lose a couple of cells. You lose a few cells. Well, Carlos Simone taught me that there's a media, normal spent culture media drop, but you're going to get about four picograms of DNA.
That's less than one copy. One copy is about six. So if you add a few more cells, you're dramatically increasing the amount of DNA you have to evaluate.
And then they cultured them from day six to day seven. Embryos that are already hatching are hatched. Embryos that were already fully mature on day six don't do well if you just culture them for another day, and you start getting cell death for sure, and that's well documented.
And, of course, then if you collect the samples, you've had a lot of reasons for at least some of the cells to die. You're going to have more DNA in the sample, and you're going to get a more reliable result. But we don't want to harm our embryos by design so that we can use NIPGT.
All the class one data today says that biopsy can be done safely. Anything can be done poorly, but biopsy can be done safely. Do you have to train for it? Yeah, we have to train for a lot of things.
That shouldn't daunt us. That should not make us fearful. And so, Brent Hansen's paper, the last one I'll close with, which was published in Fertility and Sterility in the last year or so, really looked at the same assay that Dr. Rakowski used.
And the people who had developed the assay came and were involved in running the assay in our genetics lab. They were involved in setting how embryo culture was, changed the media on day four, changed it on day three, cultured it day five or day six or day seven. And while there's a lot of detail in that paper and maybe you would like to read it if you're interested in this topic, but I will mention the following.
The best prognostic group, because it's all about predictive values, when you get a result, if you got no amplification, the sustained implantation rate was 70 percent. Seven out of ten of those embryos delivered. All ages, right? So that's really good.
That's better than we normally do. Why do you think that's the case? Because there's no cells dying. Because that embryo is really healthy.
A failure to amplify is in some sense a super selection for high-quality embryos. Still, I think it's going to be difficult to sell it to our patients. Yeah, we're going to bring you in and we're going to do this really fancy test and we're going to charge you money for it and we're really hoping to get nothing.
I think that's going to be tricky. On the other hand, there were some embryos labeled euploid by the noninvasive result and some labeled aneuploid by the noninvasive result. The sustained implantation rate in the euploids was 50 percent.
So euploid trophectoderm, euploid NIPGT did not do better than no result. But the real kicker is this. If it was euploid trophectoderm and aneuploid NIPGT, what was the implantation rate? Fifty percent.
And so the bottom line is that we're just not there. We don't have any meaningful clinical studies. And the Cochrane Review and archives and OBGYN, I believe, article that did meta-analyses found these couple of things.
But the bottom line is that I may have quoted that last one wrong, so please ignore that. But the bottom line is that as of yet we're not any place that we want to be with NIPGT. Stay tuned.
It may be better in the future, but it is not there today. And if you don't believe me, ask the group at Monash how they feel about their NIPGT platform. Thank you.
Thank you very much, Dr. Scott. So now we get to the next section. And so I think there was a question from the audience what the difference was between the first and the second.
And, you know, I'm just the moderator, but it's because basically in the first topic it was about DNA. And now it's about omics. So, for example, metabolomics in the spent media.
So, Dr. Lynn, please come to the podium to argue the pro side of this. All right. So I'll be talking about the pro side, which I want to thank Alex for putting me up here.
It's a very difficult topic, but I'll do my best whether or not it should be clinically or not. I don't disagree with anything that Dr. Scott said, but I'm going to. And obviously there's no randomized controlled trials that are out there recommending that it should be across the board recommendation in 2022.
But I think there's enough out there that maybe in a few years after future research, it could be something that could be a supplement or part of our conventional or, you know, whatever terminology you want, the current PDT style. And I just want to say to Dr. Paulson, I have no beef with you. We can have a drink right afterwards.
And so I just want to do a shout out to you. So whatever you say is correct. All right.
So I think one of the big pros of spent media, embryo media, is obviously it represents the concept of what all our patients want. We want less invasive whatever. Right.
How many times have we talked about natural cycle IVF? How many times have we talked about minimal stimulation IVF? If we have the promise, and I'm not here to talk about statistics or anything, but I still think that we should explore this technology. A lot of people think that things that we do in the lab, you know, are invasive and traumatic to the gametes. And I think it would be irresponsible for us as a reproductive society not to at least explore it.
Whether that's actually in place of conventional IVF, PGTA, I don't know. I don't think so. But it could at least be a supplement.
And it would be irresponsible for us not to at least discuss this technology as being an option for them. Another pro, obviously, is it requires no specialized training. I mean, how many of us are struggling with getting embryologists and with the incredible volumes? We're going to probably report out in SART data about 300 cycles in 2020.
And that was during COVID. That was during COVID when we were doing supposedly less cycles. So there's an incredible demand on the laboratory situation.
And anything that we can do to try to decrease the amount of workload in the lab is something that we should explore. And just to give you a frame of reference, in 2019, we did about 190, sorry, 293 cycles. So it's going to go up, and I can't even imagine what 2021 will be as all of us are struggling to cycle our patients.
So this demand puts a tremendous amount of burden on the lab, especially embryology. And it would, you know, from an operational standpoint, not to consider noninvasive PGTA as a supplement, maybe not a replacement for what we do now, I think is something that would be irresponsible for us to not at least explore. There's, I think there's probably some advantage to, especially the older patient or lesser quality embryos, which we all know are more fragile and susceptible to stress and degradation.
To be able to give them this information, I think would, in a noninvasive way, is something that needs to be considered. So it could be, have a niche possibly for older women or maybe more prognosis poor patients. And how many of us, you know, have this concept of more information is better than no information? Our patients are hungry for information, and yes, they're, you know, we should sit here, as we should, debate about a sense of responsibility about what the positive predictive value and the negative predictive value.
Obviously, I would say the negative predictive value is probably most important for our patients. But I think even though the literature is very small and the general concordance rates between noninvasive and PGTA are wide, to not enough to justify it being utilized across the board, we have to at least inform our patients that we're exploring this. We do this all the time.
We have our obvious biases. But I think we need to have a sense of responsibility that we're at least exploring this for the sake of giving them more information. Right? I mean, we are always doing autosomal recessive testing.
We're always counseling our patients and we're always engaging our patients. And I think that noninvasive PGTA might be an option for them. It gives them some information rather than no information at all.
And we need to allow the patients to choose for themselves what they want to do. And we make available to them all these technologies. Another pro is what if the laser breaks down? I mean, I know it sounds old school, you know, but that could possibly happen.
Could it be at another advantage is it could be used in conjunction with standard trophoectoderm PGTA. You know, again, we can quote references that I won't do because Jason did a nice summary there. But it could be a conjunction and more additive information to this scenario.
And it's noninvasive, so it's kind of like a why not. Now, it might not necessarily help with embryo selection, but it's going to not necessarily help with solving embryo selection per se by itself. And I don't necessarily see it as a replacement, but it's certainly going to help bring to the table that more information for the patient.
So, I mean, the kind comes down to the debate of whether noninvasive PGT should be viewed as a diagnostic test or a screening test. And we have to understand the subtle differences between those two. Is it a diagnostic test or is it a screening test? And I would argue that it could be viewed as a screening test because we still have to do always.
We always recommend the first trimester genetic testing. We always recommend the amnio. It really you need to engage the patient and try to provide security.
So why not have that information available to them? So thank you very much. Thank you. Thank you, Dr. Lane.
I think some people might have noticed that you basically took Jason's side one more time. And so essentially the PGTA or noninvasive PGTA has now been pro-argued in two different ways. We do want to cover a little bit of the spent media omics as well.
So actually Dr. Scott volunteered to do a quick pro for the spent media omics. What we do have to try and do is now keep the rest of this a bit like a presidential election debate that everybody only gets like three, four minutes. So we cover all the topics and have questions, time for Q&A at the end.
All right. Dr. Scott, you're back up. Thank you, Dr. Kwas and very briefly.
So people have been looking at things that the embryo secretes into media for almost 30 years. There were early studies using HPLC, quantitating different amino acids and some very different small proteins that were actually very helpful, particularly when you combine them in sort of Bayesian formulas to try to look at overall prediction of outcomes. Unfortunately, it was very difficult to reproduce those techniques across different labs and with different embryologists, and they didn't work out.
But they were seminal. These studies came from the U.K. They were seminal in saying that the media is modified. David Burns and McGill showed that there's a number of side chains, and you can measure those.
They did it with Raman originally, in Emory Selley's work, and then with near IR, which unfortunately didn't work as well clinically. But the concept and the data to say that the environment is indeed modified is clear. Now the technologies are much higher resolution and much more reproducible, and so particularly some of the mass spectroscopies, the MALDI-TOF sort of approaches are very impressive.
But the studies remain to be done, and so I think that looking at spent culture media, it may well be that someday we do non-invasive PGT, but then we augment that by looking at certain proteins or amino acids or free fatty acids or goodness knows what else in the spent culture media that are coming from or were modified by the embryo. So once again, I'm in favor of something, but it's just not ready for prime time yet. Thank you.
All right. Dr. Fanasiak is going to argue the con side of this topic. All right, everyone.
So as has been discussed, the kind of goal of ART is essentially to be able to select the single embryo that has the greatest potential for reproductive competence. Traditionally, morphology screening has been the mainstay. This has been augmented by morphokinetics and PGTA, and now omics in terms of proteomics and metabolomics have really come on to the stage as a new method of trying to select for embryos.
It has been hypothesized by David Gardner in 2019 that the metabolomic profile of spent culture media could be indicative of future health of offspring, which may have implications that go beyond even whether or not that embryo successfully creates a child or not. It could offer information both beyond implantation and in terms of the child's health. The embryo have remarkable metabolic plasticity, however, and this can be seen by the various forms of media that are utilized and additives which are utilized and lack thereof.
Overall, the embryo's ability to handle oxidative stress is tied to the metabolic profile, and in general, the current understanding of embryonic metabolism comes primarily from murine models and involves limited number of substrates, which include glucose, lactate, pyruvate, and other things, amongst them the amino acid glutamate. We have limited understanding of the embryonic metabolism due in large part to the techniques which are utilized to study it. Namely, these are radiolabeled substrates or microfluorescence, and the culture conditions actually can significantly alter the outcomes of these experiments.
So at the present time, there's a limited understanding of the dynamic and tightly controlled biochemistry over the course of the preimplantation period of time. In addition to the unclear understanding of the processes is how these processes are actually controlled and whether or not one pathway or the other should be promoted in order to select for an optimal embryo. One of the things that is of note is the gas chromatography and mass spectrometry, which is utilized, the primary mechanism utilized to understand these substances, requires derivatization to be performed in order for the compounds to be separated and identified.
This process actually causes metabolite conversion, which ultimately alters the very thing that's ultimately being studied. The challenge of differentiating between substances produced by the embryo itself and things that are in the culture media are also significantly challenging. So kind of in conclusion, while the omics assessment of the metabolome and proteome are of certainly high interest, the fundamental lack of understanding of embryonic metabolism is a major barrier.
Knowing when to obtain the samples and the optimal means of obtaining these samples has not been established. Further standardization of sample volume and the culture media type will also need to be overcome. Excellent.
So we move on to the last section, which is time lapse imaging. And so Dr. Lynn and Dr. Scott, let's say three to four minutes each on the pro and the con, and then we have time for questions. Mine's going to be quick.
Okay. All right. Well, I feel like in this aspect of the debate I'm looking for the upset, you remember? So I'm going to try to be Buster Douglas here upset at Mike Tyson here, so I'll try to convince you about the time lapse.
I think from a time lapse standpoint, I'll just say this, that, you know, there's a lot of technology, and it kind of makes sense, and I think it had a lot of promise. I just think the technology, we're kind of looking at it from a wrong way. We don't even know what we're looking at in terms of metrics, right, embryo development, time development of the embryos themselves.
And because of that, we can't really evaluate the technology properly. So I think, although it's not, I'm not advocating to be prime time, but I think we're kind of looking at it the wrong way. So, but we do know that from Wong et al.
in 2019 that there was some promising data that rapid expansion of blastocystin culture was associated with some, you know, robust integrative cellular mitosis in tropho-ectoderm cells. So, you know, in other words, euploid embryos expand as blast before aneuploid embryos. So there is some promise there, but I think we have to continue to look at time lapse imaging and be able to look at it in a more critical fashion and kind of decide what we're actually looking at before we really, you know, put time lapse imaging out to pasture.
So I still advocate for it being considered. Thank you. Thank you.
And we get to the final section, and that is Dr. Scott arguing against time lapse imaging. Well, thank you. Again, I'll try and be quick.
So when we think about time lapse, what we're really talking about, of course, is the rate, the temporal development of embryos. But we get a lot of different embryos, information about the embryos from time lapse. I think you might divide it into three areas.
One of which is if you see abnormal things happening. For instance, from three cells going to two cells. That's not within the normal domain of embryo development.
And when you see that, it provides insight. That's not a timing issue. It's a biologic issue.
And then also on the timing issue for these differences, we get that development. But even above and beyond that, we allow ourselves to record images so that we can capture them at just the point in development when we want. When expansion first occurs.
When the blastocele is first fully formed. Or when there's the first evidence of hatching. Which then allows a static analysis.
Not really time driven. Allows a static analysis. And, of course, AI and all those other things are going to come in there and look at that from a grayscale perspective and see if they can improve our selection and predictive values.
But in the last minute or two that I have, to say that time became very interesting to all of us. Because we knew that day six embryos didn't do as well as day five. And day sevens did poorly.
But, of course, implantation is, the timing is not just about the embryo. It's about the endometrium. And many of those embryos were simply getting out of the window of implantation that occurs in healthy normal endometrial development with appropriate normal progesterone levels.
And they're just missing that window. And so Ashley Teagues in Human Reproduction in 2019 published a really nice paper showing that if you correct for the dis-synchrony between embryonic endometrial timing. And this is work that also Dr. Frenasiak's done a lot of.
If you do that, then you'll see that the implantation rates amongst euploids from day five embryos is almost 70 percent. From day six embryos in the 60s. And is in the mid to high 50s on day seven.
So think about that. You're two days slow. Do you really think that being 30 minutes slow somewhere in the developmental cascade is actually going to prognosticate your outcome? It clearly does not.
And in fact, Linnea Goodman's randomized trial, which is my favorite, from the group at the Cleveland Clinic, clearly shows that it does not prognosticate outcome. Our own group at EVRMA, Marcos Messier, has done a lot of work in this, but it really has not prognosticated improvements in outcome. And finally, I'll say that that doesn't mean there's no role for these systems.
Again, they may be used and integrated with other technologies. We may learn more. The grayscale analysis that comes from being able to record precise images at precise moments may bring value.
There's a lot more to this. But classic time lapse I think is almost certainly not going to be impactful for our patients. Thank you.
Thank you very much. I think we've had a fascinating debate. So now what I'd like to do, if this still works, is that the last slide? It seems to not let me advance the slides anymore.
Okay. Well, then let us just do it. You know, I just say the question that was going to be on the next slide, and that is the same question as at the beginning.
So at the beginning we asked which of these technologies has the most promise. And now I'd like to ask you again, following this debate, in your opinion, which of the following holds the most promise for the non-invasive selection of embryos for transfer? So non-invasive PGTA, please raise your hand. So that's the analysis of DNA either in the blastocele fluid or in the spent media fluid, as we learned.
That's a good number. Like I would say that's already maybe a majority. Then I would say that was about 70 percent maybe.
Jason is celebrating. Then we have the evaluation of spent culture media with metabolomics. So, you know, we have at least one hand here.
Oh, Dr. Paulson has changed his mind. Okay, so we had a few there. And time-lapse imaging.
We have, I'd say, about ten hands. So the audience feels at this point that A, non-invasive PGTA has the most promise. And now we get to the question-and-answer part.
So do you have any questions for our panel or comments? Then please, you can get up and ask your question. Thanks for the great talks and this question for Dr. Scott regarding metabolics. So, actually, I learned a lot of things during this multiple different conferences about metabolics.
My understanding is this technology cannot detect segmental errors, cannot really kind of tell which chromosome is involving if there's any abnormality, and also cannot detect the mosaicism. Which technology? Metabolics. Metabolomics.
Exactly. Yeah, because they're not looking at DNA at all. Right.
So then since they have all this limitation, which basically they are looking at the implantation potential, right, for a single embryo. Well, we know that those trisomy 21s are implanted. So by finding this specific embryo has implantation potential, but some of the chromosomes are still viable and can be implanted, and if you cannot detect which chromosome is involving, do you think that there's a still feature for this technology? I do, actually.
Not to dismiss your point, though. So I like knowing what the genetic assessment of the embryo is, but remember it's an approximation, right? So you can have five trisomy 15 cells and five monosomy 15 cells in a tube, I've seen it, it looks perfectly normal. So even when you get a euploid result, you don't know for sure it's euploid.
It's just more likely to be euploid. But the performance of the embryo, the dynamics of the embryo, particularly in the latter stages, post-genomic activation, when there are a lot of things changing in these embryos, may help us further prognosticate reproductive potential, which is really the most important thing that we can do to help our patients. So maybe it will be enough on its own.
Maybe it will be additive. We need more work. It's not enough.
But you don't have to have DNA to bring value. What you need is good studies showing that you bring value, that the predicted values are high. David Adamson from San Jose.
Thanks very much, guys, for a great talk. It seems there's still a lot of confusion because all the studies are different and the studies are all different ways. But eight years ago, World Endometriosis Research Foundation published four papers that standardized the history, physical findings of surgery, tissue collection and preparation and storage, and also fluids to look at studies in endometriosis.
And today there are 50 centers around the world that have large repositories of fluid and tissue that have been collected in a pretty standardized way, and they're starting to do large studies with these materials. And I'd like to ask with such an august body of experts and with people from SART here, is there some way or some consideration perhaps to looking at a way to standardize our research in the future so we can get more consistent results and really try to get some answers for these very, very complicated biologic issues? Well, I think the answer is yes. It's a wonderful idea, obviously.
But if you look within a given assay, and there's many different ones, they do tend to get very consistent results for a given amount of starting material. And those are the data that you have, which I don't believe are sufficient to demonstrate clinical value, but where you can test these things on cell lines and show that you get the same results over and over again. So I think we know something about analytical precision and accuracy.
When you have mixed cells at different stages of development, it's much harder to get a result from an embryo. And, of course, that's different in every biopsy from every embryo, so very hard to standardize. But I think that looking at creating pools of material and looking at things in ways to standardize stuff is a superb idea.
I think having the SRM or PCRS or ESHRA simply define the criteria which we should meet to call a diagnostic valid just hypothetically would be an outstanding first step and creates a lot of confusion. The lack of that creates a lot of confusion. But, yes, I think it's a great idea.
Rick Paulsen from USC. So I really enjoyed the debate. Thank you very much for all the great data that was presented.
I think the problem is that we're debating among three different noninvasive methods as opposed to debating between invasive and noninvasive techniques. So these are noninvasive. That's great.
Time lapse. Probably not worth $150,000 for the machine, but it's noninvasive. You're looking at it.
All sorts of stuff that I think we have not yet probed. So all of these things, I think, have potential. I'd like to focus on two things that I heard.
One of them was I heard Dr. Frenesiak talk about the trauma from the biopsy of the blastocyst. And the other one I heard was Dr. Scott said the more stuff you have, the easier it is to analyze. So those are in conflict with one another.
The bigger biopsy you take, of course, the more accurate the results. That's going to come out. So I thought that was great.
So you need the smallest possible biopsy. The smallest possible biopsy is no biopsy at all is a noninvasive kind of approach. So I think that's going to be the way to go.
But I have to say it again. The biopsy is not harmless. You can demonstrate in a selected group of large blastocysts that have a large number of cells and you can take a few cells off.
But if you look at the analysis of PGTA data, there's no question that some of those blastocysts are being impeded from their implantation because of the biopsy. And the studies that are done on women under the age of 35 who have very large blastocysts, large numbers of cells, I think that's great. But your 41, 42-year-old that has a blastocyst that has maybe 50 or 60 cells and you take five off and you destroy another ten surrounding it during the biopsy process, I think does, in fact, cause harm.
So we need to keep working on these things. We need to keep working on the noninvasive selections and put them together and then also understand that this is not diagnostic. This is a screening test that allows you to prioritize which embryos you transfer first, second, and third.
So at the end, I guess there was not a question there. But I couldn't agree with you more, Rick. Well, unfortunately, Rick and I are going to end up on the opposite sides here again.
The reality is that the best biopsy is no biopsy because that provides no insight. And clearly, morphology is not enough, and we need that insight. That's where you get rid of multiple embryo transfer.
And believe me, getting to all single embryo transfer has done more to help our patients than all this other stuff combined. It's the most important part of PGTA. But the reality is there is likely a size biopsy up to which an embryo will tolerate.
Now, Magdalena Zernicke-Gertz has looked at this and worked on this in a number of different models, and it's pretty clear that there is a threshold above which you can't go. And what Shelby Neal showed in her paper also from our group is that you probably can't go crazy. The group that did poorly, some of those had 20 or more cells in them.
That's too far. You can always go too far, right? But when you're down around 5 or 10 cells, you don't see a negative effect, and that includes in older patients. This comment that we don't have any data on older patients, look at Eric Forma's data, look at Ashley Teague's data.
It has older patients. It is absolutely, absolutely available. So, no, I don't think we have data that says that we're doing harm if you can do harm.
You can always do something wrong. There's almost a million things we can do in the lab wrong and cause harm. But as of now, it can be done safely.
I think we have time for these last two questions if they're relatively quick. Yes, so I do think we can do harm, but that's not the question. The question is, is it not that these technologies are more for what you, Richard, earlier said you didn't like, which is ranking, giving preferential treatment of saying how do we decide which first.
And the Monash story that you referenced is actually a case where they deselected what they called aneuploid from non-invasive PGT and threw them away instead of saying these are now less valuable, lower on the threshold, and perhaps need actual invasive testing to confirm. And that might be, again, not necessarily the NIPGT or what they did because that would still be difficult to use it in that fashion, to have it be aneuploid and then say now we have to retest it and then you find out, well, it was wrong. So that's a problem.
But that was the biggest issue they did there was they threw away embryos that were aneuploid. But still, to be able to rank embryos, whether it's time lapse, whether it's non-invasive, I think the metabolomics, the aptamere story is what the future potentially holds, although there's a lot of work that needs to be done there. So will you rank? So I actually agree with all of that, Dean.
I think that's a very insightful statement. But the bottom line is those technologies, which I am very hopeful for for the future, I would hope that all of us are hopeful for the future, don't have any data saying they work. So what we have today, what you will talk to about your patients on Monday is based on what's available today.
And right now, PGTA gets you the highest sustained implantation rates. If you transfer every embryo, you're going to get to the same outcomes, but not short of that. And the reality is all these other techniques are very exciting.
And you're right, they might be combined. They might be useful. They might be reproducible.
They might, might, might, might. Great, let's go get the data. We don't have it yet.
So as for now, not players. Okay, one more question. So more of a comment, but it seems to me that time-lapse was the technology that enabled artificial intelligence for images and video.
Just like an enabling technology was needed for that, we probably will need an enabling technology for non-invasive as well. So probably microfluidics, lab-on-chip. But it seems that the best part about this is a biopsy is just a snapshot in time.
If we were constantly analyzing the spent culture media through a microfluidics platform, we could get much more information, just like time-lapse. Well, a biopsy for DNA is not a snapshot in time because DNA is perpetuated through future cell divisions. If you were looking at the transcriptome, it would be a snapshot in time.
But I agree, we may use all kinds of combinations for all of these things. And some really smart people with really smart engineers are going to make a lot of cool new toys for us to play with so we can have something to debate about five years from now and 10 years from now. It's very exciting.
It's very exciting. Wonderful. I think that was a great concluding statement and also actually included this topic that we didn't discuss in great detail, which is artificial intelligence, which obviously plays into this topic as well.
Well, I hope that the people that attended online and registered for this journal club enjoyed this debate despite the technical difficulties and also got a flavor of what the PCRS meeting is all about. Tomorrow we'll have another journal club and that's going to be an exciting topic as well. It's going to be in the afternoon at 2.45 and it's going to be ICSI for non-male factor infertility and we will have six fellows from universities across the country debating that.
That concludes the fertility and sterility journal club part for the PCRS guests or attendees. I have two more announcements. Number one, from Joy, that if and when you sign up for the awards dinner on Saturday night, make sure that you also get a table number ticket so that you know which table number you're at.
And then I'm supposed to also say that with a small delay after this, you can, if you would like, move straight to the UNIFI product theater and that's in Crystal H1. That's the end of the session. I hope you have a great afternoon.
