Fertility and Sterility On Air - TOC: September 2024

Take a sneak peek at this month's Fertility & Sterility! Articles discussed this month are:  
02:17 In vitro fertilization practice in patients with absolute uterine factor undergoing uterus transplant in the United States

21:22 Classification and treatment of vaginal strictures at the donor-recipient anastomosis after uterus transplant

31:18 Impact of time interval from cesarean delivery to frozen embryo transfer on reproductive and neonatal outcomes

37:37 Multiplexed serum biomarkers to discriminate nonviable and ectopic pregnancy

50:20 Urinary benzophenone-3 concentrations and ovarian reserve in a cohort of subfertile women

53:38 Assessment of pregnancy outcomes in donor oocyte thaw cycles comparing fresh embryo transfer to cryopreserved-thawed embryo transfer: a sibling oocyte study

View Fertility and Sterility September 2024, Volume 122, Issue 3:
https://www.fertstert.org/issue/S0015-0282(24)X0009-6

View Fertility and Sterility at https://www.fertstert.org/

Welcome to Fertility and Sterility On Air, the podcast where you can stay current on the latest global research in the field of reproductive medicine. This podcast brings you an overview of this month's journal, in-depth discussion with authors and other special features. F&S On Air is brought to you by Fertility and Sterility family of journals in conjunction with the American Society for Reproductive Medicine, and is hosted by Dr. Kurt Barnhart, Editor-in-Chief, Dr. Eve Feinberg, Editorial Editor, Dr. Micah Hill, Media Editor, and Dr. Pietro Bortoletto, Interactive Associate-in-Chief.

Welcome to another episode of Fertility and Sterility On Air. I'm Micah Hill, the Media Editor of F&S, and we are in September 2024, volume 122, number three. I'm joined this morning by one of our regular co-hosts, Kate Devine.

Good morning, Kate. Good morning, Micah. Happy to be here.

Great to have you. And we have our fearless Editor-in-Chief, Kurt Barnhart. Good morning, Kurt.

Good morning, Micah, and good morning, Kate. Eve and Pietro are doing summer travels, and so we have a special guest with us today, Kate O'Neill from the University of Pennsylvania, who's going to be helping us understand these articles that we're talking this month about on uterine transplantation. Good morning, Kate O'Neill.

Good morning. Thank you guys for having me. We are delighted to have a special guest today.

So let's jump right in. There's not much front matter in the journal this month. There is one inkling from Editorial Editor Michael Eisenberg on the basics of medical contraception for male contraception, essentially.

So he looks and talks about the different mechanisms that are being researched and where they're looking to target these things. It's an interesting inkling. I encourage you to read that.

There's no fertile battle this month. There are a couple of ASRM Practice Committee documents, one on fertility, drugs, and cancer, and then PGT-A Committee Opinion, always a hot topic and things that people are interested in reading about. So I encourage you to look at both of those practice documents.

We're going to jump right into the science, and Kate Devine, you're going to be presenting the seminal article this month, which is right on uterine transplantation. So let's jump right into that and start the discussion. I'll hand it over to you, Kate.

Thanks, Micah. So this article is entitled In Vitro Fertilization Practice in Patients with Absolute Uterine Factor Undergoing Uterus Transplant in the United States. And as you mentioned, we're very fortunate to have senior author Dr. Kate O'Neill here with us today.

First author is Jessica Walter, and there are colleagues from three university hospitals in the United States. This study adds 11 patients to the Baylor experience that was just published in JAMA for a total of 31 total patients who had undergone uterine transplantation, obviously with the goal of conceiving and carrying a pregnancy. The indication for the majority of these patients was mullerian agenesis, and the study also adds to the previously published European experience, largely Swedish data.

This is the largest cohort published to date, looking at the ART experiences and outcomes of patients undergoing uterine transplantation. So of the 31 transplant cases, the mean age at transplant was 31 years old. And on average, patients completed two retrieval cycles prior to transplant.

This really is a descriptive study in large part, and so different approaches to ART were taken at the three different centers. In their pre-transplant cycles, patients banked a mean of eight untested or six PGTA normal embryos, and only one of the pre-transplant retrievals needed to be completed abdominally. Six of the 31 patients had not achieved a viable pregnancy by the time they had used all of their embryos, and therefore underwent post-transplant egg retrievals, all of which were able to be completed vaginally.

Overall, the live birth rate per transfer for this cohort was 35%, so pretty good live birth rate there. And from the first embryo transfers, the live birth rate was 57%. Once patients had gone through two embryo transfers, 17 out of the 23 that had done so had a transfer, or 74% had a viable pregnancy.

The authors went on to do a deeper dive and looked at adverse outcomes among these patients who obviously, we might be concerned about risks, obstetric risks with a transplanted uterus and didn't find really differences in growth restriction, preterm birth, placental insufficiency, preeclampsia among patients that had embryos transferred from living versus deceased uterine donors. They conclude that, you know, in general, pregnancies among patients post-transplant seems to be relatively safe and successful. They also explore a variety of different approaches in terms of pre versus post-transplantation retrieval, with or without PGTA, and how many embryos really do these patients need to be able to successfully obtain a live birth.

Astutely, they note that with such a small cohort, they can't really draw definitive conclusions. That said, these data are still fascinating and really speak to how far this field of uterine transplantation has come. I'm so thrilled that we have the expert in the room with us, Dr. Kate O'Neill.

You know, I want to be a little bit provocative here since we have you and, you know, play devil's advocate just a little bit. Obviously, this is amazing medicine. There is absolutely no question.

But I think one thing that a lot of folks ask when thinking about, you know, this amazing procedure is, you know, just because we can, does that mean we should? And so, you know, there's also obviously the availability of gestational surrogacy that we have to, of course, take into account the principles of medical ethics when considering all parties, the patient who wishes to carry her own pregnancy and would not be able to do so without this amazing procedure, but also the risks to the patient, the costs to the patient and to society, and then, of course, risks to the gestational carrier, you know, was not the main focus of this article to look at the outcomes of the actual transplants. But of course, not all of the patients who underwent transplants at these center had a successful implantation and no graft reduction or anything of that nature. So, you know, we want to also always be considering when we're thinking about introducing new technology, new procedures, you know, the full picture and all of the potential complications and costs on all sides.

So I know that was kind of a tough question and a long one, Kate, but would love to hear your thoughts. No, I think that's a great question. And the honest answer is, I don't know.

Is this all because we can? Should we? I don't know. And that's why I do this. And that's why I publish the results.

And I work with my collaborators to publish the results because, you know, no other intervention do you evaluate after 20 cases and say, yep, it's a go or no, this is not good for us. You know, I think you really have to. There's a learning curve here, certainly, for you to transplant.

We've seen that the vast majority of the failures happen within the first 10 cases for all the centers. And we're, you know, we've done six cases at Penn, and I've learned something from every single case that has made the next case better, safer, more cost effective. So I think the answer to your question is going to require more.

Obviously, this is a small sample size, so it's going to require more patients and more transplants. And then I think we can really better answer that question. And since day one, people have always said to me, what's wrong with having a gestational carrier and what's wrong with adoption? And I have always said, I am the daughter of an adopted mother.

I am very, very appreciative of adoption. I do not want that to go away. I think that's a great alternative.

And I think for some people, the use of a gestational carrier is a great alternative. But I don't pretend that any of these options, uterus transplant included, is perfect or without risk. And so I just think acknowledging that you've got a bunch of imperfect solutions, really, you know, anything that is, anything that we do, we're getting patients who really, you know, are in a spot that they don't want to be.

So I think we just have to look at all of these outcomes long term, and then we can make the case, is this something that should be offered? And what's the cost going to be? And all those kinds of questions. That's a great answer. And I have one more question.

Honestly, naively, I learned so much from reading this paper, you know, and I had not even thought before about the possibility of potentially transplanting not just the uterus, but also the fallopian tubes. And your wonderful discussion goes into that, that there may be a day where these patients don't even need ART and can actually conceive naturally. How far away are we from that? You know, it's going to be a jump, because all the animal studies that are the foundation for uterus transplant that were done by Matz Brannstrom and Liza Johannesson and all of their colleagues showed that the animals had really bad adhesive disease after the uterus transplant.

Now, from my experience, my personal experience, I have not seen that same degree of adhesive disease. Really, it's these, these policies look incredibly normal. So I am always curious and wondering if we could push that a little bit further.

And I think it's just as you have more success, as you've done more cases, you feel more comfortable. You know, we had the first delivery we had was preterm. And so we were nervous about pushing in and preeclampsia and all those kinds of things.

And you get more comfortable and you say, no, this is just an elevation in creatinine because of the anti-rejection medications. We can ride it out a little bit longer. So I think that how far off are we? I don't know.

You know, somebody will do it. Somebody always does. But how much more would I need to be comfortable? I mean, I think you'd need probably in my mind, like at least 10 cases where you've seen it and you've seen what the and you've really studied that because that has not been one of the focuses.

But I think looking at that and then also, again, you really want to have a patient who understands the risks of that because having an ectopic pregnancy is not the worst thing in the world, but it's certainly any kind of pregnancy complication is not ideal in these patients. Kate, I know the numbers are small and so you guys were careful not to draw too many definitive conclusions from them. IVF before transplant and after transplant, they seem to get fewer eggs after transplant and have fewer blasts and maybe even fewer euploid blasts.

Do you have a reasoning behind that? And is your recommendation, if you can, to do to get the eggs and make embryos before undergoing this? That's a great question. And it's tough because you don't want to have to put these patients through excess IVF cycles where you don't necessarily know that the transplant will be successful. And so then they have all of these embryos and what are they going to do with them? Or in some of the patients, we had them go through multiple cycles and they ended up only using one or two embryos.

So that's hard because you don't want that. But at the same time, for many reasons, you don't want to be doing a retrieval post transplant. The biggest thing that comes to mind is you have very aberrant anatomy a lot of times.

So we know what we're doing with an egg retrieval and we see the pulsating follicle and stay away from it. But it's a little bit tougher when the ovaries aren't necessarily exactly where you expect them to be. And there may be a very large anastomosis right next to it.

So I just get nervous about that. I think that was a major driver between putting this information in is that it can be done and maybe I shouldn't be as scared as I am. But at the same time, these women are a little bit older after they've gone through the waiting period, the transplant.

And I don't know. Are these medications that they're taking going to have effects on egg quality and on blastocyst development? I think we need a lot more of this data to know that. But I do get concerned about that because of some of these preliminary findings.

We sort of answered it. Because my follow up was going to be if you have one of these patients show up and you're doing an egg retrieval, then what are the tips and tricks, things you need to be thinking about? I assume these egg retrievals are mostly being done at the same centers that are doing the transplantation itself. Yeah.

And I should add the caveat that I myself have not done a post-transplant egg retrieval. So I am just going on what my colleagues have told me. And the tips and tricks, if you can access the ovaries abdominally, a lot of times for MRKH patients, the ovaries are very high in the pelvis anyway.

And so you end up going abdominally. But for the vast majority, we're still able to do egg retrievals vaginally pre-transplant. So I think that's one of the ways to kind of stay out of some of the anastomoses and the vessels would be go abdominally.

But that's all I've got so far because I can't speak from my own personal experience. Well, so I mean, I was actually super impressed by the outcomes post-transplant. I mean, yes, it's six patients.

So it's hard to draw a ton of conclusions, but I mean, they're obviously older than they were before. And they've undergone this really massive procedure. And one would think that the technique and you just affirmed is more challenging.

So the fact that they were all able to be retrieved vaginally and they did as well as they did, I found that to be really fascinating. And it's also a subset because remember, these are everybody had embryos before they started. So these are people that went through some embryo transfers and didn't have success.

So I think that that's also something you're dealing with. It's not like they're the same patients that had didn't need a post-transplant retrieval. So I think that I agree.

I think it is, you know, it's not like if you get through that embryo cohort, you made a pre-transplant and you have to go post-transplant for retrieval. The it's looking dire for you. I think that's reassuring.

So Kate, I'm curious, can you speculate, even though it's relatively small sample size on some of the science behind this? First of all, simple question. Have we moved that everybody needs a PGTA normal embryo in uterine transplant or is that still a debate? I think I'm biased. I'm on one side of the debate and I know some of my colleagues are on the other side of the debate.

So I am on the, we do not need PGT for these patients. The vast majority of the patients, over 90%, are MRKH and they are young. You know, at our center, they've been in their early 30s, some late 20s.

And so, yes, I understand it makes everybody feel better to put back a euploid embryo. And these are the patients that you can put back. You'll have plenty of euploid embryos to choose from.

So I get all of that. And I think maybe in a patient who was older or who had failed embryo transfers before, something like that, because those patients will eventually get transplanted, we have transplanted a patient who had IVF and then had a pregnancy complication, had a uterus, had her uterus removed and now has had a transplant. So I think like those patients will come and we will gain more information.

But I think at least I'm trying to apply the same logic I do for non-transplant patients with respect to PGT to transplant patients with that small caveat. So with that as a background, we've had lots of conversations in this podcast and continually about things like recurrent implantation failure and the value of a PGT embryo. So let me see if I can frame a question that you probably can't answer.

The success rates are very good, but they're clearly not as good as a normal PGTA embryo in a quote-unquote normal patient. So can you speculate why that the success rate might be lower in a young woman that has good embryos? I know you just did a transplant. That's what I'm asking you.

But what do you think about the transplant is telling us that the pregnancy rate is 30 something as opposed to 50 something? Yeah, that's a good question. I think you need to dig into those patients because there are a few patients that have had recurrent implantation failure and are driving those down. Because if you look, the number of embryos that had to be transferred for the vast majority of patients is like in the one to two range.

So I think that there are a few patients with a small subset with a small cohort. That's the danger, right? You have these couple of patients can really drive the numbers. So I think when we exclude some of those patients and as our numbers get bigger, I think we will approach those same numbers as you see in a non-transplanted individual.

Because to get to the science question, I don't think there's necessarily anything different about the endometrium. No, I haven't done the gene expression studies. I haven't looked at the surface proteome and the endometrium.

All those things I think are fascinating and I would love to do. But I think that really these are amazingly like typical endometrium. The proportion of what one of the some of the studies I have done is looking at like the proportion of different cell types in the endometrium compared those post-transplant to control and also pre-transplant with our living donors.

And they're very, very similar in types of cell proportion. They're actually very similar in cell-cell interaction. That's some of the studies that I'm doing right now.

So I think I thought that they would be more different. I thought that the pregnancy rates would be lower because I'm like, oh, you're introducing now you've got, you know, the cells are from the cells in the endometrium are a mixture of donor and recipient. And you've got this growing fetus and that's a different haplotype also.

So, you know, what is it going to be? But I think really what I'm learning is once these cells get to where they are supposed to be, they just act like the cells that they are. They are not, you know, recognizing, oh, I'm in a foreign uterus or something. So I think it's, I don't think it's actually as different as I expected.

And I think others expected it to be. And the uterine development looks, you said the same and therefore should we generously extrapolate to wonderful things like the uterine receptivity thus is the same and, you know, and all these, you know, can we go this far to say that the uterus really is not the rate limiting step that again, it's possibly the egg that's driving it or the embryo? I mean, that's a good question. And I think that these, I think you learn a lot from the patients that you do have recurrent implantation failure on because that uterus was most of them now, not all of them.

So I think that's something you need to dive into. But most of these uteri came from women who had had children. So I think if you are putting back euploid embryos in a proven uterus, I mean, how often do you have that where you can actually like examine the individual factors like that? This is a very unique opportunity in which you can do that.

So I think in those individuals, I think there is something more than just the uterus. I think that there's something going on with the embryo, but that's so hard to study because there are so few. So that's one more plug for why we need to keep on doing uterus transplant.

So we learn not just about uterus transplant and about patients with uterine factor infertility, but so we learn about endometrial regeneration. We learn about astrumens. We learn about how to help patients with recurrent implantation failure.

This is what I keep on trying as a physician scientist is what I keep on trying to drive home is there's so much more to learn than just about uterus transplant. That's why I'm so excited to highlight your work, Kate. I mean, this is wonderful.

I think there's so much to learn from this, from the science. Clearly the reason to continue is to learn more about the science. I agree.

So congratulations. And the babies are really cute. Why don't we stick with this topic, Curt? And let's go out of order and jump to reproductive surgery.

Because there's a second article from some of the same authors, including Dr. I think that's a great segue. I was going to do the same thing. We've got the expert here.

The other paper that we purposely published at the same time from the same group, the first author in this one is Liza Johanneson, and it may need a similar author. So it's classification and treatment of vaginal strictures at the donor recipient anastomosis after uterine transplant. So this paper is a great companion.

We just heard about the success rate, but this is now very boldly saying there are some potential adverse events here and complications. And it's describing the incidence, the management of vaginal stricture after uterine transplant using this group. Again, it's a prospective cohort study looking at 42 recipients, and it's describing the post-vaginal strictures, the median time of the stricture, the severity, and then some risk factors and such that would do it.

Now, again, it's relatively small numbers, but the main findings were compared to others or just in general, this complication does happen at the anastomosis of the vagina of the two patients. It can be severe. It seems to be that it's the Meyer-Werkatansky-Kuster-Hauser patients that have the higher incidence, and it also has to do with some things like vaginal length.

But I was just really pleased that Dr. O'Neill and her group were describing this. Congratulations for not hiding this. This is a very important finding, and again, it'll teach us a lot about the surgical techniques, both at the time of transplant and how to manage it afterwards.

So I'm not going to teach everyone on the podcast exactly the classifications at this point, but I would love to hear Dr. O'Neill's comments about two things. What do you think this taught us, and what was the impetus to actually publish this? Because sometimes this kind of stuff never sees the light of day. Yes.

So these I have counted, and I have 10 additional gray hairs because of vaginal strictures. They are the bane of my existence in uterus transplant once the transplant is successful. You take a deep breath two weeks post-transplant because the uterus, at least the surgical aspect, was successful, and now I steal myself for the vaginal stricture that is inevitably going to come my way.

And it sounds kind of trivial, but it really is not. And I think when we were initially experiencing this, it was kind of at these uterus transplant meetings. We're like, is anybody else having this problem with strictures? Because mine are severe.

And people were like, oh, yeah, maybe we noticed that, but nobody had really been talking about it. And when we were looking at some of the European studies, they weren't really mentioning this and didn't seem to be reporting this at all. So we, in the U.S. experience, we have found that with particularly my Aroka-Tansky-Kusterhauser patients, vaginal strictures are the rule, not the exception.

So I think that is now how I counsel our uterus transplant patients. And I think what we are trying to get to in this is really kind of what factors are going to help us predict how severe they are. And again, very limited sample size, so it's difficult to do that.

But I think some of the things that came out, like vaginal length, if you ask me, like, what is it about 7 centimeters versus 8 centimeters? I don't think it's the absolute length. I think actually what it is probably more a reflection of is how comfortable the individual is dilating prior to transplant. A lot of women with my Aroka-Tansky-Kusterhauser have dilated, did that initially, and now they are sexually active with a male partner, and so they are no longer dilating on a regular basis.

And so getting back to the actual dilation is a mental challenge and is complicated in a way that I will never personally understand but has been communicated to me through my patients. Also, a lot of them have vaginismus, so dilation is not always straightforward. So I think people that are very comfortable dilating prior to transplant tend to be very comfortable or more comfortable dilating post-transplant, and that is absolutely necessary.

Dilating post-transplant is critical, and it's critical not just—this is because I think the reason we're seeing this in the MRKH patients is because the structural integrity and vascularity of the vagina is different in somebody that has all of those vaginal branches from the uterine artery, the cervical branches that are giving that additional blood supply. So at a healing site, it just narrows right down. And if you have MRKH patients who stop dilating, you'll see the same thing.

You lose a lot of vaginal length. So I think that's what we're seeing, so we need to make sure these patients are very comfortable dilating. And I start dilating at two weeks.

I start dilating immediately, and it terrifies Dr. Lateef, our gynecologic surgeon who did the vascular anastomosis with me because he's like, you're putting all this pressure, you're going to break the stitches. And I was like, we're either going to lose a stitch or it's going to be a stage three stricture that I can't even pass a very, very thin dilator through. So I think that's where we go.

That's the difference between a gynecologic oncologist and a reproductive endocrinologist, right? Right. I'm so brave. And they don't care about anything else other than the success of the surgery.

So do you think that's a difference, again, general, between European and American? Is the difference in the post-op care or the pre-op care of these patients that might have something to do with it? I don't know because I haven't personally been involved in the care, and there's not as much transparency to me, so I don't know exactly what happens. I think we, and I'm sure that they do this too, follow the patients very carefully. One of the things that I started doing that I wasn't doing before, and it didn't seem like was common, is I do dilation in the office.

So a lot of these patients, they are not able to tell, actually, especially early days when the anastomosis is healing. They're not able to tell if the dilator is actually passing through the anastomosis or if you're just pushing that structure far and farther and farther away so it's harder to see. And so one of the things that we started doing at our center, and I know other centers are doing, is bringing them in the office for dilation.

It's not fun, but at least I can be confident then that we're not backsliding, and especially postpartum because postpartum, when you're in that hypoestrogenic state, it really shrinks down. Kate and Micah, this is an amazing conversation because this is stuff that I feel like is a lost art, right? Talking about vaginal anatomy and post-surgery and things like that. You guys have any other tidbits you want to ask Kate about? I would just also commend you that this is something that no one would know about if you didn't report it, and that is so essential to the quality of life of these women.

And the whole reason they're having this procedure is really, it's a quality of life issue, right? And so if we were to help them have a baby but they could never have any kind of sexual intimacy again, we would be doing them a disservice. And so it's great that you have identified it and have a protocol in place really to help mitigate it. We're doing a lot of questionnaires, sexual satisfaction questionnaires.

And I think that when we eventually, we want to complete our cohort before we publish our experience. But my bet is that the sexual satisfaction of the recipients is altered because this is just, I said to one of my poor patients, this vagina is just getting so much attention right now. It's hard to think about actually enjoying intercourse and that kind of thing.

So my bet is that it will be altered and the scores will be decreased, but we'll see. Well, we look forward to a lot more work from you, Kate. This is fabulous stuff.

We're really happy to highlight you here today and these papers in the journal. Do you think this has plateaued around the country or you think that uterine transplant has got a trajectory upwards or what? I'm just curious. Well, first, thank you for publishing these papers because it is a small cohort and we do try not to overstate, but like Kate said, I think we have to draw attention to these things because to get to your question, I think it will continue to be on an upward trajectory.

There are multiple programs that are opening and some that are in the early part of their development. So I think that it will continue on. Now, of course, like the elephant in the room is cost and who's going to pay for it and how are we going to do that? So I think when we've reached the point where the centers that are willing have decided to fund it, then that's where we're going to be kind of at that point where we plateau is my bet.

But I think right now, there's at least enough interest. The majority of the experience has been on the, there's Cleveland and then Penn, UAB and Texas. But the West Coast has been completely kind of, you know, there are no programs there yet.

And we've had a ton of patients apply from California that just were not able to relocate to Pennsylvania for a uterus transplant. I get it. I couldn't pick up my life and go to, you know, move somewhere else for a trial either.

So I understand. But I think, unfortunately, the regional patterns, they haven't had access. So my hope is that that area of the country develops some programs.

I know there were some talks about it in the past. So I hope that we keep at least on an upward trajectory for the next five to 10 years. And then we have to talk about sustainability, really.

Great. Thank you, Kate. That was a great discussion.

We also have two articles from the other Kate on the podcast today. Dr. Devine has two articles. So we're going to jump into one that's from Laura Zalles and Janet Bruno-Gaston and Kate Devine.

This one is titled Impact of Time Interval from Cesarean Delivery to Frozen Embryo Transfer on Reproductive Outcomes and Neonatal Outcomes. So this is a group looking at essentially FET after C-section. And does the time from cesarean delivery to FET affect their outcomes and their birth weight and when they deliver? So this is over 6,000 FET cycles.

And this is a retrospective cohort study. They divided the time intervals into eight different intervals, less than six months, six to nine, and then every three-month interval after that until you were over two years. So they had eight different cohorts that they divided it in.

But they also looked at time as a continuous variable. So both dichotomizing it and as a continuous variable. There's some challenges when they looked at this that I found interesting.

The biggest one is the confounding. And we'll talk about that in a minute. But there are some interesting associations with how quickly people or how long the people decided to have their FET.

Obviously, the outcomes are somewhat limited. Anyone who's dealt with ART outcomes know that what we're reporting to SART is birth weight and gestational age at delivery. Those are really the two main OB outcomes that SART collects.

And so that tends to be what we collect with our IVF data unless it's under a specific protocol. So those are the outcomes they had available. They didn't have things more in-depth on OB outcomes such as preeclampsia or hypertensive disorders, gestational diabetes, those sorts of things.

Because they had so many groups, eight different groups on the time interval and the continuous variable, they used Bonferroni's correction to correct for the multiple comparisons. So we don't always see that a lot. But I appreciate when people do that so that they're reducing that risk of a type one error.

So the P to be significant, and this had to be less than 0.007 to be statistically significant. So the interesting things before we dive into the actual outcomes were just some of the associations. So as you might expect, the older someone was, there was an association with how quickly they wanted to come back.

The one that I think clinically we also see is that patients with diminished ovarian reserve came back for their frozen embryo transfer earlier. And I had a patient just last week with DOR who was asking the same thing. Can I put back two embryos even though they're euploid? Well, can I have a transfer three months after I have my delivery? And just trying to talk through with that patient that just because you have DOR, if you have a frozen embryo, we don't need to rush it.

You've got that embryo. It'll be safe. But the study definitely showed that patients with DOR were coming back earlier.

The one that I found even more surprising, though, was PGTA. I would have thought if you had a PGTA euploid embryo, you might be willing to wait longer for your frozen transfer. It was the opposite here.

PGTA was associated with an earlier time to come back for that frozen embryo transfer. So I'll just stop right there. And Kate, ask you what you thought about these sort of confounders or associations within this data set, especially the PGTA one I found surprising.

Micah, I'm just going to playfully challenge you. You're using acronyms on a podcast. I'm working so hard to get them out of the journal.

And here I am having to say, what the heck is DOR? Well said. I stand corrected, and I appreciate the correction. Diminished ovarian reserve.

So my connection somehow cut out there for the last one minute. I think you're asking about the associations between shorter time to transfer for patients that are older and had DOR. Is that right? Yeah.

And the surprising one to me was with a PGT-A euploid embryo, that they had a shorter time to coming back instead of being willing to wait, knowing that they have a euploid embryo in the bank. They were coming back quicker. Yeah.

It's really hard to know what drives that without having specific survey data, especially for having a PGTA euploid. You would think that some folks would be reassured by that as opposed to feeling that they were under the gun. That said, I do think that there's a certain type of patient that kind of wants to do everything.

And they may be the ones that want to do PGT-A and then also want to get started again right away in case it doesn't work out so that they haven't lost their opportunity. That makes sense. Well said.

So onto the results. I'm just going to summarize the results to say that overall, while there were a couple of statistically significant findings in aggregate, there really were no associations overall with the time interval to the outcomes that they were looking at. And so overall, the conclusion of the authors was to continue our counseling, follow ACOG guidance, which would be to try and delay delivery if you can, especially if you have frozen embryos.

And so overall, I would say reassuring data. But Kate, I'm curious if you had any other thoughts as one of the senior authors on this study. Any other take home points for our audience that's listening? Yeah, I mean, I do think we still need to be cautious here.

The outcomes, especially the outcome of uterine rupture, is extraordinarily rare and catastrophic and one that's probably not going to show up too often, even in a data set of this size, especially given that the number of patients who underwent very short inter-delivery intervals post C-section is a very small cohort. So I would not take this to mean throw caution to the wind. So all who are listening, please do abide by guidelines and discuss potential complications with your patients.

That said, it is always a risk-benefit calculation. And for patients who are hearing their biological clock tick with good counseling, I think it's reasonable to do a transfer maybe a little bit sooner than the full two-year inter-delivery interval if there's really not other potential complicating factors. I'm glad to hear this, Kate, because it's really important that we don't... We're always expanding the envelope in this field.

And I like the idea that the bottom line is you really should stay to guidelines. Your patients can only press you so far, should be the take home message. Right, agreed.

Great. Thank you for publishing that. So now we're going to move on to early pregnancy.

And this is actually an article that Dr. Barnhart is the first author on. And Kurt, before we dump into it real quick, just for our audience, will you just describe the process when you're submitting to the journal, when other editors are submitting their own research, do you decide if your research gets accepted? How is that process? Thanks for saying that. So whenever there's a conflict or even a potential conflict, or it's something that could appear as a conflict, there's a firewall between who's handling the papers.

So while I ultimately make the final decision on all the papers in the journal, if my name is on it, I don't make any decisions. It goes to an associate editor that I don't know. All the reviews are blinded.

I can't see them. And ultimately, they make the final decision. So I think hard about that.

Others did too. And past editors-in-chief have told me that, you know, you have to be careful about putting your own work in your own journal. But at the same token, this is sometimes where the work belongs, because that's why we work in this field.

So I'm glad to say that there is a process in place to prevent me from making that decision. But at the same token, thank you whoever accepted it for me. So Kate, you're going to present this article from Kurt looking at biomarkers for ectopic pregnancy and non-viable pregnancies.

Absolutely. And it's so fun today that we have author discussants for almost all of the papers. So we don't always have that privilege.

So this paper was entitled Multiplex Serum Biomarkers to Discriminate Non-viable and Ectopic Pregnancy. First author, our editor-in-chief, Kurt Barnhart, as discussed with co-authors from Penn, Northwestern, and EVMS. So this study evaluated 218 patients who had pain or bleeding at four to 10 weeks gestation in naturally conceived pregnancies.

So 24 biomarkers were assessed via immunoassay for each patient at a single time point. And these specific biomarkers were selected by a literature search and were previously assessed in case control studies by the same group. So in the present study, the authors used machine learning methods to evaluate models derived from combinations of these markers.

So they had already evaluated the potential predictive capacity of these markers used alone and had started to look at them in combination and now are using machine learning methods to look at building the best models they can from the combination of these biomarkers. And they are used separately, and this is important, to predict viability and then location. So with viable pregnancy meaning going on to live birth, whereas a non-viable pregnancy could either be a non-viable intrauterine pregnancy or an ectopic pregnancy.

And so the methodology they used first was a classification and regression tree analysis that weighted sensitivity and specificity equally versus maximizing one over the other. You can think about that in terms of whether they wanted for this particular scenario to prioritize minimization of false negatives versus minimization of false positives. So when the prediction by the model that optimized sensitivity matched that that optimized specificity, so they would use both models, when they agreed the classification was considered conclusive, whereas otherwise it was considered indeterminate and indeterminate and was not used.

So for the models where the maximal sensitivity and maximal specificity matched in their prediction, this prediction was then compared to the actual diagnosis. So this was the gold standard, if you will, which was determined by the findings of ultrasound and surgery. And then diagnostic accuracy parameters were calculated for that model.

The regression tree analysis using three biomarkers, specifically pregnancy-specific beta-1 glycoprotein or PSG3, chorionic gonadotropin alpha subunit and pregnancy-associated plasma protein A or PAPA maximized sensitivity and specificity at 93 and 99% respectively. And the models overall that used an overlapping group of three biomarkers for the, they call this the CART, classification and regression tree analysis, those using three biomarkers achieved max sensitivity and specificity with a max accuracy of 97%. So they then went on to look at a number of other machine learning models and methodologies.

And the authors found looking at about five of them that random forest plot performed by far the best. And so for this analysis, the data set was separated into five equal parts with three segments of the data used for training, one segment, so 20% used for optimization and one used for validation. So sort of an external validation and that was done using ROC scores.

And so again, the models were designed to maximize sensitivity and specificity. 10 biomarkers were used to predict viability and 10 were used to predict location serially, resulting in a 94% accuracy. So in conclusion, these authors found really that they were able to achieve pretty impressive diagnostic accuracy using a combination of these biomarkers as assessed by immunoassay at a single time point per patient at four to 10 weeks gestation in naturally conceived pregnancies when pain or bleeding was noted.

So the science is interesting and I can't wait to hear from Kurt. Where I struggle a little bit is, how are we gonna use this in clinical practice if at all at this point? Obviously we're looking at the biomarkers in isolation at separate and apart from the clinical picture. And we have, as Kurt has published in the past very well, lots of other great tools for assessing viability and location of pregnancy like ultrasound and just simple rate of rise of HCG.

So while this may be able to refine and improve upon it, where do we go from here? How does it help our patients, Kurt? Thanks, Kate. I wish you had been an author on the paper. You summarized that better than I could have.

So I guess the comment I'd like to say is this has been such a long time in coming. The development of a biomarkers, it's iterative steps takes literally years, if not a decade. To start from discovering these markers in proteomic experiments, then validating them in a single case control study, then combining them in another study and then getting another population.

That's the iteration of steps that have come to where what I'm publishing now. It's not just we got an assay and we played with it. And the next steps are exactly what you said.

This has to be validated again in patients where the diagnosis wasn't apparent on the same time and also with other what they call features in the model, which might be what's their baseline HCG, what's their ultrasound findings, what's their gravity and parity. So I'm not proposing this as yet a clinical test. There's more work that needs to be done, but I'm glad the science was appreciated and how long and how far it takes to get to something to be a true diagnostic test.

I just wanna clarify also, the goal here is to be what's called a companion diagnostic. I don't think we're gonna say we're no longer gonna use HCG and ultrasound to make the diagnosis, but surprisingly, a lot of people, you don't make the diagnosis as quickly as you think with ultrasound and having something else that supplements that to say, I think that ultrasound is lagging, but then you get a biomarker that says, yeah, it's not viable, you can act on it as opposed to dragging it through. So that's the goal that it's complementing these diagnoses, it's not over placing it.

And that's why our innovation, I thought, was the idea to maximize both sensitivity, especially at the same time. And if it doesn't match, then don't act on it. So in about one in five, one in seven patients that we don't get a definitive answer, I'd rather not make a mistake and just say, continue doing what you're doing.

So when you do make a diagnosis with these markers, you're gonna be pretty darn sure. Yeah, I loved that approach as well. I mean, I do think that for these patients and actually for different patients that different priorities predominate in terms of an early pregnancy, are we more worried about this being a highly valued, hard to have conceived pregnancy that we wanna push it to the, we're absolutely 100% certain it's non-viable versus those where we're really much more concerned about whether this could be an ectopic that's dangerous to this patient.

So I also loved that approach and your just rigorous analysis of these markers. I mean, if you haven't read the paper yet and you're listening, you absolutely should, because it's astounding how hard these authors work to really look at every possible iteration that they could to make sure they were coming up with something helpful. And as you say, a companion diagnostic.

One other question I had is, do you have plans to look at the potential predictive capacity of these models in conjunction with a more typical diagnostic algorithm? And then also, there's not a lot of, obviously it's a relatively small sample that was derived from a prior prospective observational or a prospective cohort. Do you have plans to kind of look at it in different populations? Obviously, positive and negative predictive value are affected by prevalence. So to look at it specifically in a population of RPL and so on and so forth.

Yeah, again, thanks for asking it. That is the plan. I want to also thank the NIH that funded this and that does exactly the aims as you just laid out.

So our next plan is to do it again, counting the ultrasound features and the patient characteristics. When we hone that, we have frozen samples in what was called the EAGER trial, which we were all familiar with, which is very, very low-risk patients that serum was collected very early in the pregnancy to see if it works in low-risk patients. And then we also have serum samples in my trial called the ACTORNOT trial, which was really high-risk patients for ectopic pregnancy to see if it works in there.

And then the other goal, the holy grail, would be if we can move it forward or earlier in gestation. So you can almost have this as a very early test on what's viable or not. I have to say this given the climate that we're in.

One of the positive features by an unnamed NIH reviewer that I really appreciated said that what we really need right now is a test for viability that therefore gives women and doctors permission to intervene in a pregnancy. Maybe it's not an RAI pregnancy, but the idea that you can confirm that this is a non-viable pregnancy and therefore get on with medical treatment is also hopefully a very valuable test. 100%.

Kurt, I wanted to say, first of all, it's been really fun to watch you push this field forward because I remember even interviewing as a fellow, saying like the holy grail, like, wouldn't it be great if we could find more, better prediction for viability, for location, all those kinds of things. And I said, whoa, that sounds hard. So this is a huge amount of work.

Were you surprised to see any overlap with viability and location? I know it was just with the PSG3, but were you thinking that there was going to be a totally different set of predictors for location versus viability? I was hoping there would be. I was hoping that there'd be something about the implantation in the tube that would set off a whole different cascade, a whole different proteins that would really be able to tell us this is in the wrong place. And there was only one marker we found that was actually higher in a ectopic pregnancy.

And that one's not panning out to be so great. Unfortunately, the overlap is because a ectopic pregnancy is kind of behaving like a failing intrauterine pregnancy. So therefore there's a lot of overlap in some of these markers.

So again, my dream would have been that specific marker for a fallopian tube implantation, but really it's the pregnancy is not growing very well. And most of these are trophoblast markers or markers of degradation or something like that. The fun part was, I don't know why, I still don't know why you can help me, why the alpha unit of HCG seemed a bit more predictive than the beta.

So that's opening up a whole new literature that's decades old that said that that might be the case because of how HCG is made in the pituitary and in the placenta. So maybe we're onto something. Thanks for that discussion.

We're going to be talking about exposures of potentially endocrine disruptors in epidemiologic type study. And this study by Emily Silva and Sruti out of Harvard and also other collaborators across actually many places is looking at urinary benzophenone-3, its concentrations in ovarian reserve in a cohort of subfertile women. So this is yet another very well done study out of Harvard and their EARTH study where they're able to assess exposures such as these chemicals and then outcomes.

And in this case, these are day three FSH values and actual follicle counts. So why are they studying this one? To tell the truth, I didn't recognize it at first. So I'm sorry, benzophenone-3 is one of the major chemicals in sunscreen.

So it blocks the damages of the sun, but in itself, because it's collecting the damage from the UV rays, can be metabolized in the body, causing again, free radicals. And we've all heard this free radical theory that free radicals, especially in the ovary, can be affecting granulosa cells and therefore affecting potentially antral and pre-antral follicles. So the idea was, and this was one of the first studies to say, is there an association of this use? By the way, this chemical, while heavily used in sunscreen is also used in a lot of other cosmetics and plastics.

So people are exposed to it even if they're not using sunscreen products. So the short answer to this for the time is that in a well-conducted study of about 142 women, they found overall no great association or no strong association between the urinary levels of this chemical and antral follicle count and FSH. And that should be the answer.

And the first study says there's no answer. But of course, every epidemiologist goes a little bit farther and they found potential effect modification. Mica has one of the best explanations of effect modification I've heard.

It's not just confounding. It's that in two different groups, the exposure has a different effect. So it's modifying the effect where in this case, in younger women, it might have a very different effect than it has in older women.

And in this case, they're suggesting when you did look at those two groups, less than 35 and older 35, there seemed to be more of an effect in younger women, where if the levels were higher, they actually did have a demonstrable decrease in antral follicle count. And in older women, they had an actually slight increase in FSH level. So the short answer is read this paper because it really tells you how to do a very good epidemiologic environment paper.

It really defines some of the limitations. It's very modest in its conclusions, but it basically does say that these chemicals we live with may have a reproductive function. I'm not sure we can go farther at this point.

Now that it says may, I read a lot of these papers and have a very high threshold before I say that compound X causes infertility or causes endometriosis, because that's a difficult thing to prove. But again, this is the kind of research that I think is well done that should be out in the literature for people to build on, to replicate. Remember, science is replication.

And that's why we're highlighting this one in the journal. Great, thank you, Kurt. That's a great summary.

We have just one more article we're gonna talk about in about 60 seconds. It's another research letter. This one is from first author, Laura Barrison, senior author, Phil Romanski and Kate Devine.

So this is titled, Assessment of Pregnancy Outcomes in Donor Oocyte Thaw Cycles Comparing Fresh Embryo Transfer to Frozen Embryo Transfer, a Sibling Oocyte Study. So this was done with donor egg bank data, and they used only donor eggs that went to patients, two different patients, one of who had a fresh embryo transfer with those frozen eggs, and one of them had a frozen embryo transfer with those frozen eggs. So there were 1,210 total recipient cycles split equally.

605 had a fresh embryo transfer, 605 had a frozen thawed embryo transfer. They use generalized estimating equations to account for the non-independence of those cycles and to adjust for any confounders that were important. And just straight to the outcomes, there was a 51% ongoing pregnancy in the fresh embryo transfers and 50% in the cryopreserved or frozen embryo transfers.

So there was not a difference. And I thought this was a very nice research letter, a very simple way using donor sibling oocytes to look at that fresh versus frozen embryo transfer question that we've had in donor egg cycles. And so I appreciate this research letter, and I thought it's just a powerful tool as a way to sort of isolate the effect by using sibling oocytes from donors.

Kate, did you have any other thoughts on another really cool article from you? Well, just the background on this is that, you know, we'd looked retrospectively at all of our donor cycles and for a long time, and many of these were with fresh eggs as opposed to egg banks. So I don't know that you can necessarily extrapolate, but we had seen lower ongoing pregnancy rates from frozen cycles, even when we separated out the fact that the first transfer was often fresh with the subsequent being frozen. And so for a long time, I've always favored doing fresh transfers when doing donor eggs, even though I wasn't really totally able to explain why.

And so I think this was a really clean way to look at it, and I feel much better about it now, especially given the convenience that frozen cycles yield. And so I'm happy to be able to reassure my patients. Yeah, and I don't think you were the only one that has had that observation.

We've heard that from other groups as well, and this is a great way to look at that question in the absence of a randomized trial, which I think would be hard to do to answer this question. Do you think we've answered this question yet, Kate? Do we still have that lingering feeling that somehow there's a detriment in frozen? I mean, I think that it would be hard to do an RCT. I think unless we were going to, this was the best that we could come up with.

And I think we did our best to try to control for any other potential covariates that would be problematic for drawing conclusions. So I feel pretty good about it. I don't know, what do you think, Kurt? Yeah, I agree that the way to study it is going to be really, really hard, and sometimes we're going to have to come up with observational study, but I think there's subtlety there.

The good news is it's not a really big issue, but I still worry about some of the non-science stuff, like you don't know which eggs you're getting from an egg bank. Not every egg is equal in the same cohort and the numbers and things like that. So I still think that there's issues beyond what's the quantification of if any detriment, if at all, by freezing the egg first.

Yeah, no, and it's hard to know, again, whether you can extrapolate to fresh egg donation cycles, although I think most of us are doing fewer and fewer of those. And I also did always struggle with the biologic plausibility here. Why would frozen cycles be worse from donor eggs, but not from autologous, even though it's something that we seem to see? So this accords much more with logic for me, but we shouldn't pick and choose, of course, what we want to believe.

Well said. As always, we're only covering some of the articles. There's some great articles in other sections of the journal this month, some good video articles.

There's a lot of letters to the editors. So if you want to read some controversy over recurrent implantation failure, controversy over people's opinions on the practice committee, on PGTA, there's a lot of good things to read in the journal for the month of September. So I encourage you to do that.

As always, like and subscribe to our podcast. You can find it anywhere where you find podcasts. And by the time you're listening to this, we will have the podcast that was recorded live at ESHRE.

Two episodes will be dropped. Be sure to listen to those if you weren't able to attend EHSRE. And of course, we will be doing the podcast live from ASRM.

So if you're at ASRM in October, come by the podcast booth, say hi. We'd love to chat with you on the podcast. Kate and Kurt, as always, fantastic discussions.

I learned a lot from both of you. Thank you. Thanks, Micah.

Thanks, Micah. I've been getting nice comments by people as I've traveled that they like the podcast. So we keep that coming.

We appreciate you listening. But I also would be happy to say how you think we might improve the podcast too. So it doesn't always have to be complimentary.

But anyway, pleasure working with you both. And thanks again. This concludes our episode of Fertility and Sterility On Air, brought to you by Fertility and Sterility in conjunction with the American Society for Reproductive Medicine.

This podcast is produced by Dr. Molly Kornfield and Dr. Adriana Wong. This podcast was developed by Fertility and Sterility and the American Society for Reproductive Medicine as an educational resource in service to its members and other practicing clinicians. While the podcast reflects the views of the authors and the hosts, it is not intended to be the only approved standard of practice or to direct an exclusive course of treatment.

The opinions expressed are those of the discussants and do not reflect Fertility and Sterility or the American Society for Reproductive Medicine.