Fertility and Sterility On Air - Unplugged: August 2025

In this month's Fertility & Sterility: Unplugged, we take a look at articles from F&S's sister journals! Topics this month include: impact of environmental toxins on in vivo gametes (1:30); the effect of embryo vitrification on neonatal outcomes (15:40); impact of compressive force on gene expression in uterine fibroids (31:17); the role of automation in the IVF lab (42:25).

F&S Reviews:  https://www.fertstertreviews.org/article/S2666-5719(25)00004-0/fulltext
F&S Reports: https://www.fertstertreports.org/article/S2666-3341(25)00112-6/fulltext
F&S Science: https://www.fertstertscience.org/article/S2666-335X(25)00048-5/fulltext
Consider this: https://www.fertstert.org/news-do/potential-automated-ivf-lab

View the sister journals at:

• https://www.fertstertreviews.org
• https://www.fertstertreports.org
• https://www.fertstertscience.org

F&S On Air is brought to you by the Fertility and Sterility Family of Journals in conjunction with the American Society for Reproductive Medicine. Hi everyone, and welcome to another episode of F&S Unplugged. I'm your co-host Pietro Bordoletto, back with the whole crew today, Daylon, Blake, and Molly.

How are you guys? 100%. Blake just told me he was up in Oregon and did not come visit or say hi, so I'm a little peeved over here. I know, I do regret that I did not see you.

I barely had time to see the friends that I was there seeing, so I'm very sorry, Molly, but I'm very glad to see you guys today and be here. Yeah, I didn't come by and see Molly either, mostly because I was buried. I was waist deep in the science in Fertility and Sterility.

And Blake, I was wondering a little bit on how to intro your article, but I think in light of you being at a wedding, and I suspect there were some libations involved, I think the connection here is that you partook in some toxicology over the weekend in Oregon, and then this article is talking a little bit about in vivo gamete toxicology. Go ahead and make the link for the listener. I will make the link as best as I can.

I don't know what you're talking about in terms of toxins. I just sat on the ground, enjoyed a nice conversation with friends, and no consumption of anything happened. So I'm going to talk about this article called "In vivo gamete toxicology in the context of in vitro fertilization, a narrative review" by first author Morgan Orsolini and senior author Danny Schust of Duke.

So a little bit of background here, IVF has existed since the 70s, and yet success rates, although have come a long way since then, they're still much lower than we would like. How many times do we as physicians talk to our patients about, is there anything else that I can do, or what can I improve upon, and sometimes the answer is just try it again. But there are many factors that contribute to IVF success, and gamete quality is inarguably very integral to IVF treatment success.

As we know, a woman is born possessing all of the oocytes that she'll have in her entire life, and these oocytes are arrested. I feel like I'm talking to my fellows here, which I kind of am. I'm sure they're listening eventually to this, but they're arrested at the diplotene phase, a prophase one, mark it down for your boards.

That's what I was going to say. You took the words right out of my mouth. Yeah.

These oocytes are arrested in diplotene phase or prophase one, and these unrecruited follicles, but they still can uptake chemicals during childhood and adolescence and adulthood before being recruited to ultimately undergo maturation ovulation. On the contrary, men have this unfair advantage in which the life cycle of spermatogenesis is undergoing constant renewal. Even if they're exposed to environmental toxins, you still eventually will have renewal of this sperm, so a shorter time in which exposure may cause adverse implications for the sperm.

And so this review aimed to provide clinicians with a comprehensive reference of potential toxicology exposures or toxic exposures by evaluating the existing literature on reproductive toxicology and its implications on IVF outcomes. So as a lot of these review articles have, there is an outstanding table one, and it has a very excellent summary of numerous, numerous categories of toxins and their major effects on human health, as well as the in vitro and animal study results. So I'm going to summarize some more of the heavy hitting ones, the common ones that we hear about in numerous studies, but as always, I encourage you to go back and take a look at that.

So first I want to talk about heavy metals. So these are naturally occurring and ubiquitously exposed, whether it be naturally or via mining, industrial use, agricultural, et cetera. So for example, we're talking about mercury, cadmium, lead, these are considered endocrine disrupting chemicals, and they bind to estrogen receptors have been found to bind estrogen receptors and other hormone receptors and can cause disrupting of intracellular signaling cascades.

They also bind to different enzyme groups, the sulfhydryl one in particular, and they can disrupt various energy production signals and transduction pathways. There are studies that have shown that they can alter the zona pellucida, the actual structure of the zona, and therefore increase exposure to reactive oxygen species, because the zona structure is altered. There's also been studies that have shown that cumulus cells have been shown to be steroidogenically inactive, in which this could contribute to poor oocyte competence as well.

But let's not make everything entirely about the oocyte. Lead and mercury can cross the blood testes barrier and accumulates for totally lytic cells and has been shown to be associated with significantly decreased IVF outcomes based off of particular studies. They also dive into organic pollutants, so these are generally considered lipophilic and have very lengthy half-lives because of this, and they can be resistant to degradation, just environmental degradation.

So these include things like flame retardants, industrial chemicals and their byproducts, pesticides, things that many, many people are exposed to very commonly. And so something that I learned about the structure of these pollutants, so they have polychlorinated biphenyls, or also known as PCBs. These are used in a lot of the plastics, copy paper, adhesive, inks, etc.

A lot of which were banned in 1979, according to this paper, but some of them still certainly do exist. But they have these aryl hydrocarbon receptor ligands, or AHR for short. And so these AHRs have been found to play an integral role in testicular structure and function, as well as even oocyte function.

And so its expression is associated with improved sperm quality, oocyte quality in certain animal models. And so when you're exposed to these things, they can bind to the ligand of these, or their ligand themselves, these plastics and these pollutants, and they bind to these AHRs, and they can alter the functionality of the testicle or the ovaries. And it's been shown to alter the functionality of these structures.

So obviously some of this is going to be presumed, and these animal models will show that this can possibly affect IVF outcomes, if you translate that into the human model. There are certain PCB treated rats that have shown high rates of polyspermy, smaller testicles, reduced angiofollicle numbers, as well as embryo arrest. So a couple other ones I'm going to go over.

These are polybrominated diphenyl ethers. It's been a long time since I've stated these long organic compounds, but we will call them PBDEs for short. So these are things such as flame retardants.

A lot of these are banned in 09 by the EPA, but they are still also found in household products. They're also found in, there are certain studies that show that they have been found in follicular fluid of humans, of women undergoing IVF. That can't be good.

No, it cannot be at all. So there are a lot of mammal studies that show that these PBDEs are known to be endocrine disruptors and are detrimental to reproductive health. So obviously when found in follicular fluid, that raises concern.

There are studies that show that women with detectable follicular fluid of these chemicals have had as high as a 10 times greater chance of implantation failure. Obviously these studies are quite limited, but certainly raise concern nonetheless. And then the last couple I'm going to go over are pesticides.

Obviously something that's very commonly were around as well, but in murine and bovine animal models or embryo models, these have been associated with significantly reduced blast formation rates. And there's a previous study from 2002 that showed that over 50% of tested follicular fluid samples had some form of combination of these pesticides. And although it's unclear if this adversely affects human IVF outcomes, obviously still has some concern because of what we see in the animal models.

And then they combined a lot of other, there's several other ones that they go over, many, many other compounds. And a lot of these review articles, as you know, they are, they're quite lengthy, but I want to just hit the highlighted ones here, but they discover, or excuse me, to talk about ubiquitously exposed environmental chemicals, such as insecticides, phthalates, and bisphenols, which are commonly seen in plastics. And so these are also found in electronics, nonstick pans, many things that we have in our household.

And they talk about their numerous associated adverse reproductive outcomes in animal models in both male and females. So the authors conclude that exposure to environmental toxins can impair both male and female fertility. Many environmental toxins are capable of accumulating in reproductive tissues and impacting gamete viability.

And although clinicians are in general aware of potential environmental risk, in vivo gamete exposures are too often excluded during infertility workup in treatment is one of the authors' main concerns. And so they stress that assessment of the risk of a patient should become an integral part of every fertility evaluation. A lot of things to unpack in this article.

I think probably the most commonly recognized reaction I had was just, we're unsafe from everything. And almost everything we do is there's a toxic exposure. And of course, we, I think it's important to keep in mind things we can eliminate in general, but it's, it's kind of shocking.

Just like it says all over this paper, it's ubiquitous. We're exposed to a lot of these things. Some of these things are theoretical that it causes adverse outcomes, but certainly makes you think about all of the things that you're exposed to at all points during the day.

So what do you guys think about all this stuff? I'll tell you what I tell my patients who ask about this. And I have a small but growing number of patients who will proactively show up and ask about these exposures. I tell them you can't fix everything in your environment, but there's definitely some big obvious things that you can tackle.

And the easy wins are don't microwave anything in plastic. That's a easy fix. And then the second one is try to avoid drinking particularly warm or hot liquids out of plastic containing bottles.

I think the more you can do in aluminum and the more you can do in glass, the better you are from limiting and exposure perspectives. But those are kind of, that's kind of where I start and end the conversation. Yeah, absolutely.

And it's, you know, Molly, I was, as we were talking about, I was in Oregon this last weekend. It's interesting just hearing, my wife and I were talking about the differences in geography of just being in Oklahoma all the time and compared to Oregon and just something as simple as we're just buying something at a store, like a gift shop. And they're like, well, we don't, we don't have plastic bags anymore.

They like, they don't sell anything plastic. And I, my wife and I were like, man, Oklahoma could, they would never talk about that. They just, they never mentioned being worried about plastic.

Sorry, I'm just dogging on my state, but it's something that's, it is something that's very obvious when you, when you're, you know, even just in that state for a very short amount of time. So being cognizant of those things and that being on the forefront of your mind is something that we certainly can do as providers and counseling our patients. It's really nice when things that are environmentally friendly and improve the environment for everyone else.

And all these other things we're worried about also are the best thing for our bodies. So reduced plastic, reusable glass and aluminum are kind of simple, simple fixes that it doesn't always work out that way, but it's really convenient how it helps though. Guys, I don't want to take it to a dark place, but I live, my, my partner in life is, is highly vigilant on these matters.

And I'm just gonna, gonna, gonna say it. I'm going to say the quiet part. It's a ground we're all screwed.

Ubiquitous is the word. And we can take measures, but like truthfully, I mean, the, the concentration of these compounds in our environment as we walk around and in, in our specialty here, the similarity to sex steroids and the interface with endocrine biology makes these things particularly insidious, but not just in terms of, you know, reproductive health, but all our development across the board and not to mention, you know, outside of reproduction is our health generally with microplastics. It's really, it's really a grim, grim scenario.

And I, I, I agree that we have to, on an individual, individual level, take measures. I think mostly with our, our young, our young ones we have more control over. And, you know, as soon as they come out of the gate nowadays, at least in my bubble, perhaps not in your bubble, Blake, but in our, in our bubble in Brooklyn, New York, it is like a battleground that everyone's aware of.

And it's like an arms race almost. And people are looking at you cross if you, if you, if you walk around with the, you know, an old school Nalgene water bottle, you're an ass. So and rightfully perhaps, but I think not to go all full dark, Rambo dark here, but bringing it back to the light, I think the important thing about studies like this is that they kind of all in one place, capture the scope and ubiquitous nature of the exposure.

And that helps to make a case for action at a regulatory level. And that's where I would say most of the change is, is really meaningful, is regulating the use of all these compounds, notably, and I'm going on here, but I think it's important to note that in, in, in most of the world, you have to prove something is safe. You have to prove a chemical compound is safe in order to include it in the formula.

In America, it's the opposite. You have to prove a thing is toxic or dangerous in order to remove it. And there are literally thousands of variants of even just one of these families, you know, and it can be BPA one day, and then it's B something else A. It's a moving target.

So the vigilance is appropriate. The, the prospects are grim, but I think studies like this are really key to moving the needle again, at a societal and regulatory level. Yeah, well said for sure.

Well, now that we've kind of spooked every listener and every patient on the topic, let's, let's kind of continue on the theme of is what we're doing and what we're exposing ourselves to having any impact on our patients and their offspring. This one's a little bit more in our wheelhouse. Molly, tell us a little bit about the difference between children born after embryo vitrification and if they differ from siblings born after fresh embryo transfer.

Yeah, I think that article Blake just reviewed, I'm going to just print it out and keep a stack in my office. I'd be like, yes, these are the things to do. Yeah.

Well, like I said, that table is, is real. It is good. You know, it's like something I'll probably put in my counseling for patients.

I have like a Rolodex of pictures, but that is something that would be very high yield. And here's something you can do. Here's a list of things you can try and avoid.

So sorry to revert back to my grim paper again, but. So my paper is called "Do children born after embryo vitrification differ from siblings born after fresh embryo transfer". And the first author is Florence Belva.

And the last author is Lisbet Van Landuyt. And they are coming out of Belgium, which is where they practice. And so I think in this group and for most of our listeners, and we've talked about this before in the podcast, we're all pretty aware of there are many benefits of embryo vitrification.

Quicker turnaround or to allow for the turnaround in time for genetic testing for aneuploidy or mutations to reduce the risk of OHSS, which I think we just talked about one or two podcasts ago, to keep our options open if the first transfer is unsuccessful or for future children, and to better line up a future transfer with a more receptive lining rather than a fresh transfer. However, many studies have supported that frozen or vitrified embryos are associated with larger babies, more large for gestational age offspring compared to fresh transfers. And this has been shown in both sibling and non-sibling studies already.

But I think I always read these studies with kind of in the back of my mind, I'm thinking about a lot of confounders. There's a lot of confounders at play. The ones that I think of the most is that most frozen embryos historically were transferred in completely programmed or artificial cycles.

And just recently we've really pushed towards more natural cycles in our practices. And so then the question is, is it the programmed cycle or is it the frozen embryo leading to bigger babies? In addition, we were doing more frozen transfers in really high responders. That really introduces the confounder of PCOS.

And we know people with PCOS may have more risk for gestational diabetes, more risk for bigger babies as well. And those are just a couple of confounders that I think of, as well as your first baby when you're younger might be a fresh transfer. And then you have your backup frozen embryos for babies two and three, and our babies two and three are often bigger than our first baby.

So the authors of this study, to make a kind of a new perspective of the same question, utilized sibling studies using full siblings. And they were really trying to create these sub-analyses to offset these confounders as much as possible from both maternal influence, as well as the paternal contribution and the environment. And they used newer techniques to do this analysis to really as many controls as possible.

So this was part of a prospective cohort study that looked at the association between outcomes after a frozen versus fresh embryo transfer. Their institution in Belgium has a follow-up program for children who are born from ART, and they've been following them for more than 30 years now. These are really well verified.

They have actual follow-up visits of the children to see how they're doing. The authors looked at sibling pairs of singletons born to mothers with both fresh and vitrified embryos that were transferred from 2008 till 2021, and they looked irrespective of the orders. So I assumed it would all be first fresh transfer, then frozen transfers, but they looked at both fresh and frozen, and then someone who maybe needed to do another cycle, frozen and fresh.

And if they had multiple children all born through IVF, they picked the two that were closest in age for the study. So they looked at 1,340 pairs of 2,680 children. There were 1,016 in the fresh to frozen group, and only 169 in the frozen to fresh group, which makes sense to me.

Transfer fresh first, then you move to your frozen. But 155 pairs were after biopsy for PGT-A, and they don't go into that, but I'm sort of surprised since we don't do PGT-A with fresh transfer unless you have a lab with extremely fast turnaround time. So I'm interested in that.

Also interesting is that two-thirds of the frozen embryos were transferred in natural cycles. And so that's really kind of more advanced than I think a lot of at least my peers in my own practice have been in terms of the transition towards natural cycles. So between 2008, 2021, two-thirds of these frozen embryos were getting natural cycle transfers.

They looked at the size of the babies with different parameters. They looked at NICU admission, congenital malformations. What they found was that the gestational age of delivery, the length of the offspring, the head circumference, pretty similar fresh versus frozen.

NICU admission, congenital malformations, again, similar in these sibling pairs. But again, they did find consistent with prior studies, birth weight was higher in frozen embryo transfers even after adjusting for the treatment type and maternal characteristics. And after adjustment, they also found that the frozen embryo transfers were associated with less prematurity, increased risk for large for gestational age, which is kind of a similar side to the same point of birth weight, but just another way of looking at that.

In their sub-analyses, they looked at the fresh to frozen group as well as the frozen to fresh. They looked at day of transfer. They looked at whether the embryos were biopsied or not.

And consistently through this, they found that frozen embryo transfer was associated with increased birth weight, increased risk of large for gestational age. And they also did adjustments for treatment type, maternal characteristics, as I mentioned. A point that they make in their discussion that was interesting, because I'm always thinking about the parity fact where each baby tends to get bigger for a mom.

They said that the average parity increase is about 80 to 118 grams with each offspring, and that their increase they saw with the fresh to frozen was 240 grams. And in prior studies, the addition of freezing increases by 222 to 244 grams. So I thought it was just nice to have some numbers there and seeing, okay, yeah, it does go by about 100 grams each baby, but if you freeze, it's going to be 200 to 250 grams, which is more substantial.

They had less prematurity, which was really interesting for siblings born at frozen embryo transfer. And I wasn't totally sure why that was. I think overall, we've definitely seen this effect multiple times.

We've reviewed studies like this on this podcast before. I mean, this is another well-designed, differently designed study that really supported that same finding, but we still just don't know why. We still don't have that answer.

And I think that's really where we need to go next with this. We need to study that more in depth. I counsel my patients, frozen transfers increase the risk of a little bit of a bigger baby.

My patients aren't that fazed by that. And usually we have really good medical reasons that we're freezing embryos. But what I don't know is, okay, bigger baby, what does that mean? Does it mean bigger teratoid delivery, hemorrhage, maybe risk of shoulder dystocia? And are there changes in metabolic programming for this child? Because that's really important to know as well.

I think it would be nice. This prospective study really has the potential to have that data. So I'd like to see that next from this authors.

I saw the authors in 2023 in F&S compared fresh versus frozen embryos from an earlier cohort, and they didn't do a sibling pair for that one. And they actually followed the kids through two years old and found there was really not difference past larger birth weight, but I'd really love to see more extended data if they have that and this larger cohort and looking at the siblings. I think, you know, in animal studies, we know that IVF culture does induce epigenetic changes somewhat robustly, specifically in the placentas, not so much in the offspring from the studies that we see.

So placentas, but not as much as the fetuses. And so the larger birth weight, is that related to the placenta? Is it just placental epigenetic changes and then it won't perpetuate in the child? I don't know. I think we just need a little bit more why about this, and then need to know how big of a problem is this? Is it just a big baby? Is it just a little bit more obstetric complications? They change just a little, that can be a big deal too.

Or is this something that's potentially this, the 2% of IVF births in the United States are going to have more metabolic syndrome related to that. The other piece I would just wanted to say, I think I've gone on long enough, but I wonder if there are some studies that refute this finding. Most studies say frozen bigger babies, a few don't.

And I wonder if lab techniques, right? These are all from one group in one country. And so I wonder how vitrification techniques could potentially alter this as well. What do you guys think, thoughts on this topic or for where we should go with that future research that I think we definitely need? I think it's a pretty cool study.

This is not entirely new information, as you had alluded to. We've seen this information in numerous studies before. What I thought was pretty cool was that it's their sibling embryos.

And I think that's the unique thing about this study. Just a couple of things that were crossing my mind when I was going through this is some of it is a little bit heterogeneic in that they have some day three transfers in there and some embryos cryopreserved to day five, day six. Does that really make so much of a difference? Not entirely sure.

But when you're trying to make things as clean as possible, that's one thing that's like, well, some of these are day three transfers. Does that have an impact on things? And then the other thing is too, when you look at the differences in the weight, you know, it says anywhere from like 80 to 200 grams, is that something that's clinically significant enough to where you're just going to tell a patient to routinely freeze an embryo and transfer it? I would say not necessarily, but I'm curious to your thoughts. I want to ask the real scientist in the room, Dalen, tell us if you had to put your thinking cap on.

Why? Why do you think this difference is there? Well, the why, I'm going to leave to the experts. All right, then answer me the how. What is potentiating this potential small difference? Are we talking methylation? Are we talking metabolomics? What is it about vitrification that you think is making this so? Well, I think that there is a lot of pre-implantation embryo biology that we take for granted because it's self-contained and intrinsic, right? But it's a week of development where you have a lot of key shifts in gene expression and a lot of coordination of the chromatin in order to be poised for a real rapid deployment of fundamental cellular molecular events that are going to underlie this rapid pattern formation and establishment of the maternal-fetal interface, et cetera, et cetera, et cetera.

So any insult during this phase, I can imagine, and when I say leave it to the experts, I feel like there's good evidence in animal studies to show that there are changes that are being affected by this cryopreservation and thaw process. How those are linked, I think, is a deeper question. Whether they're clinically meaningful, I think, is really the important output here.

Like, how much do we care about this? But I think, you know, from just a, I'd say, maybe cautionary standpoint, the idea that there is a difference is, I don't want to call it troubling, but I think that it's a real thing, right? Because it just raises this prospect of having, as Molly said, I mean, this is a huge percentage, you know, maybe not by proportion, but it's a lot of human beings, right? We're talking about millions of people and disproportionately distributed within our society, right? So you just wonder about how this is going to bear out over the course of the lifespan, that we don't really have resolution on this sort of like degenerative disease phase of all these patients. You know, the oldest of all these IVF babies is my age, and I'm not that old, guys. So I think, you know, we have a lot of learning to do, not so much about development anymore, but about the pathology that might be related to IVF.

But again, it circles back to the question of like, then what? Are we going to change? Are we now going to all do fresh transfers? No. So what's the meaning of this? It's so deep. So what's the meaning, but also I think if it really is potentiating a problem, because if it's just a 200 gram difference in birth weight and that's it, that's very different than it's 200 gram birth weight.

And then you have this metabolic, you name it, syndrome difference that is potentiated later in life. That's a big deal. And if so, then I think we also have to take the next step forward is what can we do to mitigate it? And how can we track down to where that potential added risk is coming from? Is it truly just vitrification? Is it media? Is it micromanipulation? Is it progesterone supplementation? When we go to use those embryos in drilling down at the, doing a little bit of root cause analysis, buzzword, and figuring out if there's a potential for mitigation while preserving the clinical outcome to that patient.

Yeah. Well, again, I don't want to make this could be like the dark episode, starting with Blake and now talking about the potential downstream sequelae, but I will say that, you know, small differences early can be magnified over the course of time. And also just in terms of like checking ourselves and being a little reflective, it seems a little bit naive now in retrospect to think that just because we're able to get a live birth as an outcome, that these pretty dramatic interventions, you know, whether it be embryo biopsy or literal cryopreservation to negative 200 degrees Celsius, and then it's not, it's doing nothing, right? The idea that it's doing nothing, I think is kind of silly.

Again, how, how big a deal it is, is something that it's, it's our job to, I think, calibrate, as you said, Pietro. And I think the area for hope, I think for both of these studies we talked about, I mean, there is some data on adding antioxidants for vitrification and potentially offsetting some of those methylation changes. So are there other components should we go the antioxidant route and study that more? And then I'm also thinking about, you know, Blake's paper that all these things are so ubiquitous.

Well, is there something we can give to offset those effects? If we know that we can't completely eliminate the plastics from the environment, for example. So I think that's our area for hope and future research. The embryo culture dish is plastic.

I mean, but I, but I believe it is a, and I don't want to speak for the embryologist, but I believe it is a inert, safe plastic that has been thoroughly evaluated. And same thing with our catheter tips and our syringes where we pass embryos back into uterus from, I think, I hope. So we got new evidence that BPL is no longer safe.

I mean, let's keep our fingers crossed, guys. We're doing more good than, than, than harm. I'll say that much.

At least you guys are. Thanks, Molly. That was a great article.

Lots of good fodder for discussion. Daylon, I want to come back to you now for your article from F&S Science on the topic that to me as a reproductive surgeon, I'm particularly interested in. I love, love, love the idea of mechanotransduction, which for the listeners, essentially the translation of a mechanical force into a biochemical signal.

Uterus is a big muscle, has the potential to have things inside of it that are a result of mechanotransduction or potentially made worse by mechanotransduction. Tell us a little bit about this study from the University of Cincinnati. That's exactly the lines I was thinking along there, Pietro.

The uterus is a big muscle. What better form or platform for studying mechanotransduction? But really, the story that I got to tell is it's about fibroids. And usually when I hear someone say they got a story about fibroids, that's my cue that some REI is going to tell a long story and regale us about the legend of the crazy volume that he took out of a patient, he or her, or she took out of a patient once upon a time.

That's my fibroid joke that I always make when I'm telling a fibroid story. But today it's my fibroid story. And am I telling that the taking out is really just the beginning.

But let me back up just for a bit of review here. So uterine fibroids are leiomyoma. They're these aberrant growths that occur throughout the uterus.

And although they're benign, they can contribute to subfertility by either interfering with implantation or decidualization, as well as maybe other unknown undefined causes. And when patients with fibroids do get pregnant, they have an increased risk of complications like miscarriage, preterm labor, placental abruption. And the incidence of fibroid is really high.

This is a mind boggling stat for me, that 70% of women at some point are estimated to have been affected with fibroids by the age of 50. I mean, that's a huge percentage, most women. But whether fibroids affect fertility and or pregnancy and whether surgical intervention is warranted is variable and can be kind of nuanced, I would guess.

I mean, I don't have personal experience on this, but depending on the size, location, the abundance of these growths, among other considerations, I don't know. I'll ask you guys, do you have like a simple shorthand when considering action on fibroids or is every patient kind of a case on its own? The tough thing about fibroids is it's usually not just one fibroid. It's rare that you get one big obvious fibroid.

Most of the time you're dealing with multiple different fibroids of different sizes in different locations, which one, make it really hard to study. It's a pretty heterogeneous condition. Two, not every fibroid is symptomatic.

And sometimes you find out about fibroids because they're causing heavy pain and bleeding, but sometimes the symptom is infertility and sometimes it's an implantation failure, pregnancy loss. Part of, I think, the lack of action or understanding of how fibroids impact fertility and how to overcome it is that it's just an inherently tough thing to study by nature of the disease. So case by case is what I'm hearing there and complex and varied.

And all those considerations, I mean, I think they touch a lot on like the macro elements of the fibroid or fibroids, as you say, as a condition, but I'm here focusing on this story that's more of a glimpse into the micro and molecular facet of things. And in this case, first authors, Carolyn Nietupski and Megan Sax with lead author Stacey Schutte, who are all at U Cincinnati. They focus, as you mentioned in the jump there, Pietro, mechanotransduction in fibroids.

Now mechanotransduction has been the subject of increased focus across cell and developmental biology with mounting evidence suggesting a whole world of biomechanical cues that govern cell fate and function at the molecular level, particularly in my field focusing on, you know, pluripotent stem cells and differentiation. This study, in my opinion, is so beautiful not only for the approach, which I'm going to come around to in a sec, but also the rationale. As we alluded to there, what better system for studying mechanotransduction than the uterus, which is effectively a large muscle, but also what better pathology to study than fibroids, which both contribute to but are also affected by the biomechanical processes and properties of their site of origin, right? So getting back to the approach here, from a technical standpoint, I thought this was like a real state-of-the-art story here.

They combine primary patient samples in vitro cell culture models that incorporate variations in biomechanical force that I thought were elegant and relatively simple and straightforward, but elegant, along with a suite of omics analysis. So just to drill down a bit, the investigators took patient-matched fibroid and healthy myometrial cells from five patients and used those tissues to develop this in vitro 3D spheroid culture model. And then these spheroids were embedded in agarose, which, as you guys may know, is kind of like jello mold.

And then they put a weight, a defined weight, on top to simulate a distributed compressive force, and then performed histological transcriptomic and proteomic analyses, finding that there were 61 clinically relevant genes that were differentially expressed. I mean, clinically relevant, you'll have to go to the paper to see what that means. Also to see, you know, what that means for our understanding of and or treatment of disease, as I say.

You guys should really have a look at the paper. And the results, I don't think, were overwhelming, not going to change the way we treat. But for me, the takeaway was more the innovation around the approach and the potential application, both to expand upon the results that were shared here, these genes that were differentially expressed in response to pressure, but also more for me is the capacity for this model and the system to test other hypotheses that center around mechanotransduction and cellular function and or pathology in the uterus.

So I was invested in this. You know, I love any cell culture model that has like an organoid component and trying to recapitulate the biology of a system. And this really hit all the markers for me.

I would invite you guys to comment. What are your thoughts? It makes me wonder that maybe we've missed the boat on prevention strategies for fibroids. Fibroids are symptomatic for months to years before they're diagnosed.

And if we were able to diagnose sooner, is there a world in which a mechanotransducing pharmacologic target could mitigate some of the progression of disease down the road? You had an anti-inflammatory, an anti-spasmodic agent, a anti-muscarinic muscle relaxing therapy, something that settles this large muscle and prevents it from transducing signals that potentiate growth. Wouldn't that be a heck of a lot cooler than a hormonal option? Right. I heard someone say the other day that this, your thought, Pietro, it's in line with that.

If part of an annual exam or maybe like biannual exam would just be a pelvic ultrasound for women and you know, you possibly find these asymptomatic fibroids and you could act earlier than now you're having bulk symptoms and heavy pelvic bleeding and now you've got this massive fibroid to remove. So that just got me thinking, would that be part of a good idea? Part of an annual exam for a patient or every couple of years or something like that, doing a pelvic ultrasound to see if they have something like this. Because 70% of women, I mean, that's a lot of women.

So it's not like you're searching for something that's extremely uncommon, but that's very, very prevalent as Daylon had mentioned. So just food for thought. Yeah.

I think we also do see a lot of asymptomatic fibroids in our practice, right? We're seeing people and scanning them all the time for other things to say, oh, you have this six centimeter interior fibroid. Are you having both symptoms? Are you having urinary? No, no, no problem at all. Although you also have the people who say, you know, I always have had this weird symptom.

I always have had, you know, heavier periods than my peers. And sometimes you are putting the pieces together. So yeah.

I would argue that the symptom is potentially the infertility for which they're seeing you for. Right. Well, all of your thoughts, I think are right on.

And the takeaway for me on this is this meta idea of, as you mentioned there, Pietro, this approach, a pharmacologic approach to focus on the kind of the macro mechanics is what you're talking about, the muscular contractions that you see in our aberrant in a uterus with fibroids. But I think the real impact here is that what we're talking about is that the site where these fibroids exist is subject to a lot of contraction. And while we can appreciate the macro contraction, what the cells are seeing are these micro molecular contractions often mediated by channels called piezo or receptors called piezo one, piezo two, which are druggable, as you said there.

Nobel Prize winning piezo. Absolutely. And that's why it was such an innovation because it showed that the cell can respond to a mechanical cue.

So the mechanical input or output of this pathologic or affected uterus and how that influences the cells within the fibroid, I think that's what we can test. That's what we can deconstruct. And if we can drug it, maybe that's what will allow us to understand the transition from asymptomatic fibroid to something that perhaps results in either discernible symptoms for the patient or infertility.

And that's something once we can understand that transition or what underlies the pathology there from a cellular molecular perspective, then we can drug it, then we can stop it from progressing and treat early and infect these huge unmet needs. So this is, I think, really drilling down on what the hope is that the authors are getting at and what's so exciting about this era we're living in at the interface of pharma and cell biology. Well, perhaps one day we'll look back on this podcast, dust it off and just laugh at, man, how little we knew back then.

Look at how far we've come. Guys, we're going to stick in this kind of futuristic what comes next from our last article from Consider This. I'll start with a question.

Do we think robots, AI, closed-loop systems could finally take some of the variability and maybe some of the cost out of IVF? Petra, you didn't send an article, so that sentence just threw me for a loop. Yeah. Like, which one is he going to pick this month? Yeah.

Let me rock your world. All right. So in this month's Consider This article, we're talking about whether or not a fully automated IVF lab is actually moving out of science fiction and towards the standard of care.

The reason why this matters is global demand for IVF is far outstripping the trained embryology workforce. This drives up costs, this creates access bottlenecks, and I think the industry is calling on automation to help solve this problem with scale without compromising quality. This article, I think, is a must-read for anyone who's thinking about what comes next in our field because it has a couple of key themes that I think are imminently important when we consider the role of automation.

The three big themes that I think this article hits on are validation, automation as an access lever, and then the utility of automation to create data feedback loops. So from a validation perspective, we all want this to be so. I think it would be killer if we had a really highly functioning automated lab.

However, if we're going to move embryology from this manual, largely artisanal profession towards something that is much more automation-friendly, we have to have prospective validation studies that show that, at a minimum, we're not inferior to the current best practices, but potentially superior to existing practices, but driven by data. From an access lever, automation is really cool in that, if the promise of automation comes out to be true, it will reduce labor bottlenecks. It would improve standardization across sites.

You're yet to see it in our field. Nothing ever actually lowers the cost per cycle, but this is one thing that has the real potential to lower the cost per cycle, maybe. I'd love to see that actually be borne out to be true.

I think the part that I'm probably most intrigued about is the data that's generated through automation. Having a digitally instrumented lab creates structured data streams that could be really helpful for QA, for benchmarking, for AI-driven optimization. If you're putting your research hat on, imagine controlling all of these different variables in a rigorous way, and then changing one thing out, media, changing the micropipette out, changing pH.

There's so much control that one can develop that allows for rigorous study of discrete interventions. That's pretty freaking cool. I think if all of this sounds awesome, it does sound really awesome, but there are some very real implications for people who are considering developing these tools, introducing these tools into clinical practice, but also for our field from an ethical and intellectual perspective.

One, I think it's going to change how we staff and train embryologists, who truly do see automation enter the field in a meaningful way. Embryologists will move away from repetitive tasks to more oversight-specific tasks. It will increase scalability and throughput.

However, if you don't have the resources to support the scalable IVF lab, like nurses, patient navigators, physicians, then you kind of fall short on scalability. Then finally, there's some regulatory pathways here that I think are kind of uncharted territory. What amount of FDA clearance is going to be required for these big integrated systems that manipulate gametes and embryos? It hasn't really been sorted out yet because we haven't been here before.

I, for one, am really excited about it. As someone who's building an IVF lab from scratch at my new practice, Terra Fertility, we're thinking about all of the pieces of tech that we are putting into the lab and what are the things that are setting us up for not only opening next month, but also getting ready for the next… Shameless plug. September 2nd.

September 2nd, totally shameless. Join the waitlist. State your disclosures.

Terra Fertility, love it. From a very real perspective, though, you guys, I'm very thoughtful about what tech I buy for the lab so that I can make sure that my team of people running the tech are well-supported and well set up for scale, delivering a really strong clinical outcome, but also being able to collect some really cool data that we can use to improve patient care and share with others. I really like this article.

I think it's very future-facing. If you're thinking about how automation is going to affect your practice, I think this is a must-read article. I think the COI here is that the authors of this article are from the Conceivable Life Sciences group that are doing a lot of this early automation work through their Aura platform, but I think they do a very nice job of having a measured take on automation, both the pros, the cons, the limitations, and some pitfalls that we could potentially be facing from a people-in-society perspective.

So big ups to these authors. A must-read. Really easy to read, really interesting.

I'm glad to see it and consider this. Fascinating to think that that could be where we're at one day. You know, I wonder what embryologists think of this.

I haven't personally sat down and talked to ours in our lab, what they would think about it. I don't know, what do you guys think? Have you talked to any of your embryologists? Or what was the context of this paper, since we weren't able to read it, Pietro? Were they in favor of it? Or more of just an idea? No, I think these authors and the reason why this article, I think, made it to consider this is, yes, it's written by industry folks who are invested in the success of the idea of automation. They take a really measured approach to make sure that they're not over-promising on what the technology can do, and not acknowledging what some of the very real concerns are that people like embryologists have.

I think there's either a Temptations or a Smokey Robinson song, what becomes of the brokenhearted? What becomes of the embryologist when you've taken away their strippers and their pipettes to be able to do some of the tasks that they do and give them a different set of tasks or roles in the embryology lab? I think it is sentimental, but I think this is a largely cottage industry for its first 40 years. It's artisanal, there's a lot of working with your hands and the human factors to all of this. But I think the next 40 are going to be different, and we have to be prepared for it.

Absolutely, and I agree. I don't mean to diminish the sentiment that is due. I just mean that the sentimental argument, I don't think, holds up in the face of all the VCs that are gobbling up the practice.

I think the real practical question that I have here, and it is the question you always have with ART, because it is the point of the spear, is you've got to give me a comp. You can say a lot about how it makes sense. Yeah, of course, there's a great rationale.

There's a lot of upside, but I need a comp where the stakes are lower, where you can flesh out the feasibility and deal with all the pitfalls. Because I don't think you can go right to 11 with this without pissing a lot of people off, namely the patients and regulatory bodies. I think that we need a comp that just doesn't exist because ART is so multivariate, and there's so many players involved.

I think that's why it is cottage industry and so bespoke, I think, because the stakes are really, really high. The process, as much as you guys take it for granted, is pretty complex. The biology that we take for granted, we don't even understand as evidenced by the previous stories we just talked about.

The comp needs to be something lower stakes, but at the same level of sophistication before I think you can reasonably answer that question. I don't know what that is. Maybe in the modern era, something with personalized genomics, or maybe, I don't know, biopsies of cancer patients and in vitro culture in order to drug screen or something.

If you can automate something like that, that has a lot of moving parts and has serious stakes, but not directly to the patient, I think that then maybe we'd be ready to put embryos into these apparatus. I think we're beyond putting embryos into this apparatus, Daylon. There are babies born already from a lot of different pieces of automation, AI-driven plate preparation, autonomous incubation systems.

We're on the verge of having full-fledged success from an end-to-end solution in the lab, I think, within a handful of years. I wouldn't be surprised if this is next year from the group in Mexico that's rapidly developing this technology. I wouldn't be surprised if it was September 2nd.

I mean, Terranova, my friend. You said it, not me. Guys, we've covered a lot of disparate topics in the podcast today.

I think it goes to show you that there's a little bit of everything for everyone in the F&S family of journals. One of the things that we're really excited about is you've probably gotten tired of listening to me, Blake, Molly, and Daylon. You've probably gotten tired of listening to me, Micah, Kate, Eve, and Kurt on the other podcast.

There's going to be a third podcast episode that's going to be dropping every month that's going to be focusing on the fertile battle in views and reviews section of the journal. It's two article types that you don't hear us talk a lot about On Air or Unplugged, but it's such a rich amount of content that we thought it deserves its own podcast episode. Dr. Emily Barnard and Dr. Ben Peipert are going to be hosting and producing this new third F&S podcast episode that you'll start to see if you are a subscriber to the F&S podcast series.

We hope to show it to you guys. Hope you like it. Give us some feedback on it.

Our goal is to eventually get to one episode a week from different group of authors, podcast hosts who won't just be hearing from us, but we've heard loud and clear that you guys want more content and we'll try to give it to you when we can. So be on the lookout for this new podcast type coming out in the fall from the F&S Family Journals. That's all the time we have for today.

Thank you for listening to another episode of F&S Unplugged. 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.