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BackTable / OBGYN / Podcast / Transcript #25

Podcast Transcript: Placenta Accreta Spectrum (PAS)

with Dr. Brett Einerson

In this episode, Drs. Mark Hoffman and Amy Park invite Dr. Brett Einerson to speak about the diagnosis and management of placenta accreta spectrum (PAS) disorders. You can read the full transcript below and listen to this episode here on BackTable.com.

Table of Contents

(1) Defining Placenta Accreta Spectrum (PAS)

(2) The Multidisciplinary Approach to Placenta Accreta Spectrum Treatment

(3) Regionalization of Care: The Patient and Practitioner’s Perspective

(4) Diagnosing Placenta Accreta Spectrum

(5) Best Practices for Placenta Accreta Spectrum

(6) Placenta Accreta Spectrum Morbidities

(7) Postpartum Treatment & the Emotional Toll of Placenta Accreta Spectrum

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Placenta Accreta Spectrum (PAS) with Dr. Brett Einerson on the BackTable OBGYN Podcast)
Ep 25 Placenta Accreta Spectrum (PAS) with Dr. Brett Einerson
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[Dr. Mark Hoffman]
Hello everyone and welcome to the BackTable OBGYN podcast, your source for all things obstetrics and gynecology. You can find all previous episodes of our podcast on Spotify, Apple Podcasts, and on backtable.com.

[Dr. Amy Park]
Hi, this is Amy Park and I'm here at BackTable OBGYN again with my co-host Mark Hoffman. Mark, how are you doing today?

[Dr. Mark Hoffman]
Good, clinic day. How about you?

[Dr. Amy Park]:
Good. Got a lot of stuff done today and we have a very special guest today. His name is Dr. Brett Einerson. Dr. Einerson is an assistant professor of OBGYN in the Division of Maternal-Fetal Medicine at the University of Utah. His research focuses on placenta accreta spectrum, severe maternal morbidity, quality improvement in patient safety, obstetric and postpartum hemorrhage, and cost-effectiveness. He's currently funded by the NICHD on a K-23 grant to study alternative treatments for a placenta accreta spectrum.

He's a nationally and internationally recognized clinical expert in the diagnosis and management of placenta accreta spectrum disorders and is the director of Utah Placenta Accreta Program at the University of Utah, which is one of the busiest referral programs for PAS in the United States. I'm just going to go ahead and dive right into some questions for you, Brett. Tell me how did you get interested in this? What's your background? How has your interest and career evolved along this path?

[Dr. Brett Einerson]
Sure, Amy and Mark, thanks for having me. I'm excited about this. I stumbled into placenta accreta spectrum during fellowship. I had been a resident in Chicago and Northwestern and had a real love of clinical obstetrics and was conflicted about giving up gynecology but loved pregnancy. I really felt at home doing pregnancy counseling and research in that area.

I chose to do the MFM fellowship in Utah. Utah is a place where they see a lot of crazy stuff. Placenta accreta spectrum wasn't necessarily on my list of top five things I was most interested in when coming to Utah. I thought I was going to come out here, learn MFM, do some good research, and then find a job maybe back in the Midwest where I grew up doing general MFM.

During my fellowship I just encountered a lot of cases of placenta accreta spectrum, in part because people have a lot of babies out here in Utah and access to VBAC is not all that good in the rural west. I started seeing that these patients have really difficult cases. They have really difficult diagnoses to make and there wasn't a ton of research informing how to take care of them.

I got really sucked in in part because it just felt like there was a void of high-quality research. There was a challenge in taking care of these patients from a diagnostic perspective. There was a challenge taking care of patients with PAS, placenta accreta spectrum surgically, and I just sort of fell in love with that challenge or those challenges.

(1) Defining Placenta Accreta Spectrum (PAS)

[Dr. Amy Park]
What's the average parody of the patients, would you say?

[Dr. Brett Einerson]
It's funny because I read placenta accreta studies from other countries and the median number of prior C-sections is sometimes zero or one in these studies from overseas. Our average, accreta patients have had at least two or three prior C-sections. I've had patients who've had 5, 6, 7, 10 babies. Overall, in Utah family size is almost twice as large as the national average.

[Dr. Amy Park]
Wow. Well, tell us what is PAS? What is the nomenclature? How do you even define it?

[Dr. Brett Einerson]
Sure. A lot of probably what we'll talk about today, this is an evolving area, but placenta accreta spectrum has always been known to be this obstetric complication where the placenta attaches abnormally into the uterus and doesn't let go at the time of delivery. And as a result, if you force the placenta to come off when it's attached abnormally, it results in significant hemorrhage that's much worse than it would be if it was uterine atony or some other cause of postpartum hemorrhage.

We think placenta accreta spectrum happens and starts off very early in pregnancy. The placenta probably attaches abnormally very early on in its development in an area that's scarred or damaged within the uterus. Placenta accreta spectrum exists on a spectrum. There are milder cases really where the placenta is just abnormally attached. It may not even look all that different either sonographically or physically at the time of delivery.

Then there's very, very severe cases in which the placenta essentially attaches into the prior scar, totally remodels the uterus, distorts the normal pelvic anatomy, and changes the normal pelvic vasculature into a superhighway of blood flow. In short, it's an attachment problem and it's a remodeling problem. No matter how you think it develops or forms or what it's caused by, the end result is pretty clear. It's a really difficult delivery that's at high risk for massive bleeding.

[Dr. Amy Park]
How do you even describe it in terms of are there grades? I don't know, it's been a long time and maybe things have evolved. I don't think that we just had accreta, increta, percreta. I mean are there stages now or how do you even describe it?

[Dr. Brett Einerson]
This is confusing because it's changing really rapidly over the last three to five years. Traditionally, the way we describe placenta accreta was in the framework of a placenta that's abnormally growing into the wall of the uterus, and so there were different grades. A placenta accreta spectrum which includes accreta or creta, which is the mildest form, where the placenta is abnormally attached but not necessarily invading into the wall of the uterus. Then increta and percreta are progressively worse manifestations of a progressively invading placenta, where the placenta invades further through the wall. In percreta, you can even have an invasion past the serosa into the bladder or into other organs in the pelvis.

That's really the way that the disease has been described since the '60s or even before. The nomenclature didn't really change much for this, which used to be a relatively rare disease through the 20th and into the 21st century. Increasingly, pathologists and clinicians are noting that that description of placenta accreta maybe doesn't capture what the disease looks like in the hands of the surgeon. It may look like that when the pathologist gets a specimen that we've wrestled out of the abdomen and torn out the side wall of the uterus.

In general, the way that the disease acts in the body and at the time of surgery, in my opinion, is that the placenta attaches into a C-section scar, remodels or doesn't remodel the uterus and really transforms and remodels the uterus. We're starting to talk a lot more about clinical grades, what the disease looks like at the time of delivery, if you can actually see it. That's defined by the FIGO staging.

FIGO in 2019 came out with a clinical staging that's FIGO 1, 2, 3, based on the appearance of the disease in utero, with 1 being essentially attachment without other changes. 2 being vascular appearance changes on the outside of the uterus but no placenta extending all the way to the serosa. Then percreta or what used to be called percreta, now stage 3 being placenta that extends all the way to the serosa. You can see it at the time of surgery underneath a thin layer of serosa and then significant vascular changes.

[Dr. Mark Hoffman]
When you say remodeling, can you be more specific or more-- I guess talk to a gynecologist. What do you mean when you say remodeling?

[Dr. Brett Einerson]
That's a great question. The remodeling that we think happens during placenta accreta spectrum is that you've got an embryo or an early placenta that attaches into a very small area of C-section scar or other scar from prior surgery. Those cells that are microscopic at the time of an implantation grow into a full-blown organ, a placenta that has to grow somewhere. In the most severe forms of placenta accreta spectrum, it grows within a C-section scar. That early placenta, which is microscopic or very small, turns into a full organ, the size, you remember placentas from residency, size of a flat volleyball.

[Dr. Mark Hoffman]
I do remember those.

[Dr. Amy Park]:
It's been a minute for me, it's like since 2006 really.

[Dr. Brett Einerson]
It's got to grow somewhere. If it's attached abnormally into a small area of scar, it's going to stretch and distort and grow into that scar, distorting the part of the uterus that it's attached to. Remodeling to me means sometimes you open up the abdomen, what you see is a snowman. You've got the baby in the amniotic fluid at the top and then you've got this placenta that's totally remodeled, the lower part of the snowman or the lower part of the peanut shaped uterus.

It really is, we think, growth within a confined space and lack of freedom for that placenta to develop normally like it should on the side of the uterus. Instead of that, it's growing within a confined space, within the scar remodeling not only the uterus but the parametria and the bladder and the vessels in that area.

[Dr. Amy Park]
I just want to shout out that Brett just published this exact thing in The Green Journal, March 2023. I think you even appeared on a podcast or it was one of the featured articles and there's a journal club. It was really cool and I encourage our listeners to read it because even for me, I'm not an obstetrician anymore, but cool clinical pictures from time of surgery, imaging pictures, and the pathology. Just mind-blowing paradigm shift in terms of how we conceive of placental-- It's not placental invasion as much as it's the uterine remodeling part that I really thought was very interesting.

The other thing I wanted to ask you about is that, this point brings up doing abstract and video reviews for all of these conferences like SGS and AGL. Treating the uterine niche is so hot, isthmocele, like people are doing tons of it. I've seen lots of different techniques. Section D and C, you can do a resectoscope, you can laparoscopically fix it, robotically fix it. Lots of different ways. I've seen wedge resection. What is your take of the niches and does that work really well? What's the data behind it? Presumably, that's the beginning of PAS. I don't know, tell me.

[Dr. Brett Einerson]:
I love that question in part because it gets at the heart of the work that we've been trying to do including in that study that you mentioned. The way that I have come to think about placenta accreta spectrum is more a disorder of the uterus in which the placenta is not an innocent bystander but the placenta is not the offending organ. To me, the uterus or a defective scar specifically is the issue.

It stands to reason that if we can make a better scar in the first place or fix bad scars that form after prior uterine surgery specifically C-section. Maybe it's a cesarean scar pregnancy treatment or a myomectomy or a prior other intrauterine surgery, it stands to reason that we would reduce the risk for placenta accreta spectrum in the future. Those studies are very hard to do because following people perspectively after those surgeries would still require a ton of people to even get a few cases of placenta accreta spectrum. This continues to be a relatively rare problem, about 1 in 1000 pregnancies we think.

Prospective research is really lacking and very, very hard to do outside of large multi-state even multinational studies. My hunch is that if there is a large keeping niche in the lower part of the uterus that serves as a really hospitable home for a future case of placenta accreta spectrum. There is some data to suggest that embryos may be more likely to implant in a large niche versus just a prior cesarean scar. I think that data are currently lacking to overwhelmingly or full-throatily say, "We should be fixing all of these," or, "Here are the characteristics of niches that we should be fixing."

That being said, people are moving forward full bore. Even in MFM, it's leaching into our world, like what the heck do we do with this preconception consultation that comes with a uterine niche or isthmocele? Are we supposed to be repairing those, resecting those? We honestly don't know. I look forward to researchers informing that question more because in part I wonder are you taking out one scar and adding another? That gives me a little bit of pause.

If you take out a gaping niche and make it a little bit better does that reduce the risk? I'm not sure that it does. I think we need more data. The jury's still out. I'm really looking forward to the collaborations between MIS and REI and MFM and really across the breadth of our specialty to figure this question out because it's an important one. More and more patients with ultrasound being performed preconception and early in pregnancy, more and more at the time we're seeing this and we don't know what to do with it.

(2) The Multidisciplinary Approach to Placenta Accreta Spectrum Treatment

[Dr. Amy Park]
Yes, I was just going to comment on that because way back when we were lucky to get a dating ultrasound. But ultrasound has become so much more accessible, better in terms of the clarity, et cetera, and it seems like there's just so many more C-sections scar pregnancies that are getting diagnosed. I think at least the Cleveland clinics have gotten a reputation for treating these.

That just brings up another question about what you just alluded to, like who should be owning this? What specialty? Because you're MFM and Justin Lapin is MFM and you guys do complex surgery. This is badass surgery, like much respect. You could tell that the residents when you came were like, "This guy knows," because you had all the pictures. It is like really tough surgery but some places it's MIGS, a lot of places it's ORC. You have a big collaboration with radiology.

I just had this conversation with my friend who's the upcoming president of SGO, Amanda Fader, and we were just talking about should ORC be owning PAS? I think they're like “Not us,” but I think some of them are like “We should be doing it.” I don't know. I'm not sure. I'm not part of that debate stream.

[Dr. Brett Einerson]
It's close to the bladder Amy. I think UroGyn probably should be the ones to own that.

[Dr. Amy Park]
No, I'm one of those not-it people but anyway, it's interesting. It seems very local. It seems like MFM definitely is involved on some level, but you take a lot of ownership. You have a program. You're the director of this thing and you get a lot of referrals through this network that you have. Just curious about your thoughts.

[Dr. Brett Einerson]
I think the answer to who owns this is all of us. The difficult thing is that this is a pathology and a disease that exists between subspecialties and even exists between specialties. You can be the best surgeon in the world. If you don't have a good OB anesthesiologist and blood bank, you can't take good care of patients with placenta accreta spectrum.

This is, I like to say, interdisciplinary. The thing that's leached in the literature is multidisciplinary but it's really interdisciplinary care for these patients. I think that there isn't one specialty optimally situated to be the future caretaker for these patients. It's imperative on OB-GYNs to, I think, be the central rallying force around getting radiology, NICU, OB anesthesiology, pathology, and the various subspecialists together to do as good a job of taking care of these patients locally and regionally.

To some degree, MFM makes a little bit of sense because it's the one where most MFMs have at least some familiarity with their imaging and interest and investment in getting the diagnosis right. The problem of course for MFMs is that for many of us, 75% of our specialty is consultative. Many MFMs don't cover labor, delivery, much less want to perform a planned cesarean hysterectomy. In those cases for the average or meeting MFM, it's imperative to rally a team.

I think about interdisciplinary care as there needs to be a champion locally if you're going to be a center that takes care of placenta accreta spectrum. I know colleagues from general OB-GYN who do that really well. I have colleagues from GYNORC who are that team at their local institution. There's MFMs who do it clearly, there are MIS people who do that really well. I think whatever subspecialty it is, I think that there has to be active investment in understanding the imaging and the surgery, and the pathology. That in itself is an impossible task for one type of subspecialist and really requires an interdisciplinary approach.

I think gynecologists are incredible in the work that they do, but a lot of them do not come out of fellowship having seen a ton of cases. If you talk with our gynecologists, although they are the best situated to handle difficult pelvic surgery, a lot of them just haven't seen enough cases to be familiar with the pitfalls and avoid the worst outcomes during a PAS case. A lot of their training is on the fly. Once they get out of fellowship, they get called in for these difficult cases. To me, locally and regionally, it's about finding a team to put together who's going to really concentrate on getting better at this really difficult surgery. That's going to probably involve multiple subspecialists.

[Dr. Amy Park]
Can you just talk a little bit about your journey? It's just hard, like you're saying, to get the volume even if you're an MFM, you're a referral center so you're getting it but how did you get trained up? How did you assemble your team? How do you take calls? These are all very crucial elements.

[Dr. Brett Einerson]
Sure. Yes, I took interest in placenta accreta spectrum from a research perspective first and then figured out that clinically and surgically. It was a challenge that I wanted to take on. Midway through my fellowship, I started going to as many accreta cases as I could possibly go to. Even if I wasn't the fellow assigned to the cases, as one of the surgical assistants, I was there to see the surgical team operate.

It's remarkable how much I learned from just watching cases even when I wasn't there operating. You see the pitfalls, you see the approaches that work and the approaches that don't. I was able to see 25 to 30 cases during my fellowship and by the time I graduated, I had been one of the surgeons assisting on most of the cases that I had seen. I showed up to learn about the surgery, learn about the way that other people in the department were handling it. At the time it was mostly MFM delivering the baby, the gynecologist did the hysterectomy.

There were gynecologists who taught me a lot. At the end of my fellowship when I said, "I want to build this PAS program and I want to make this as good as possible for patients," I had gynecologists who already knew me, who were willing to invest in me, who were willing to walk me through cases, who were willing to be my surgical assist for the first couple of cases that I had as attending and they really helped me to do that. At the end of about 18 months, they and I agreed, "All right these are cases that Brett and a small team of non-gynecologist can handle and when things get difficult or if the disease is really bad, we'll have the gynecologist there on backup."

[Dr. Mark Hoffman]
That's such a great point for learners, for trainees. I think Elliot Richard said the same thing. Most of it's just showing up. A lot of it is in getting into the OR and watching other people operate, watching how they get set up, watching the team, how they interact with the other people in the room, watching how they physically do the techniques. To become an expert in something, just sometimes watching as opposed to when you're actually in there doing it and you're really focused on a small narrow window of a procedure, watching something can let you see a bit more of the whole thing. It's a great, great lesson there, a great story in how you went from becoming just someone who wanted to watch a bunch to becoming honestly the expert in this. That's a great story.

(3) Regionalization of Care: The Patient and Practitioner’s Perspective

[Dr. Amy Park]
Well, I wanted to ask about the regionalization of care because that's always been a hot topic of high-volume centers and high-volume surgeons taking care of these conditions. I think that's definitely been a theme throughout UroGyn, now for MIGS and we're talking about plus PAS, but it's a burden for the patients. Chatting about this rural west situation and what's the average travel time and how do you provide for the patients who are coming in and have six other kids at home and when do you require for them to come? It's a heavy lift for these families to come in.

[Dr. Brett Einerson]
We looked at our data on proximity to care here in Salt Lake and the population centers are highly concentrated along the Wasatch, which is a mountain range that runs from southern Idaho basically down to almost Arizona. The vast majority of people in Utah live within a couple of miles east or west of that range, but we looked at where our patients were coming from and 65% were coming from more than 45 minutes away.

One of the reasons I was interested in that is because 45 minutes is my distance at which my sphincter tone increases and I'm worried about that person being at home. If they start bleeding at 28 weeks, I don't want them to be more than 45 minutes from the hospital and even, honestly, you want them to be closer if they're going to start to bleed, but a full third of our patients come from more than three hours away. It is a unique challenge of location. The same is true of my colleagues who work in Arkansas. The same is true of my colleagues who even work in parts of the Midwest and even parts of the Southeast.

I think that wherever you are in the country, you're going to have patients that are coming from long distances. The reality is that volume and experience almost certainly matter if PAS care mimics basically every other surgical subspecialty, and there's no reason to think that it won't. If you don't see something, except for every couple of years, you're not going to be as familiar with avoiding the problems of PAS surgery as if you see a couple of months. It's really our job, I think, to figure out how to do this thoughtfully to say, "The best outcome is probably--" Well, first of all, we should show that the best outcomes are going to come at higher volume centers.

Second of all, we should figure out ways to make it accessible to people who don't live near one of those places. A lot of my patients, in fact, disproportionately, come from places that don't have access to tertiary care medicine. Because they don't have access to VBAC in parts of Idaho and parts of Montana and parts of Wyoming. It's a huge financial burden and logistical burden for them to come at 30 or 32 weeks and live in Salt Lake City for a couple weeks and then deliver and spend a few more weeks in Salt Lake City while their baby is growing and feeding in the NICU. That's an incredible burden that we're only beginning to understand.

I don't have a magic wand to hear the problem of how do we make our hospitals fit to do this in more areas of the country, but I do think that for the time being, regionalization of care is going to lead to better outcomes because of volume.

[Dr. Amy Park]
How did you assemble your team? Do you have an interdisciplinary team and how do you organize it? Do you have weekly conferences? What are the logistics to establish best practices and review the cases, et cetera?

[Dr. Brett Einerson]
We're only beginning to understand best practice. It's hard to make recommendations for other centers that may only see six or seven cases a year and compare their processes to a really, really busy center that's seeing multiple consults every week for placenta accreta spectrum, but I think that there are a couple things that everybody should be doing. I can talk a little bit about how we have operationalized this.

To me, it's important to have formalized communication in some way. I'm sort of an email hater, so you'll have to forgive me, but email is not the greatest for interdisciplinary discussions. It's fine and if it's what you've got, then try to optimize it, but I think that there is benefit in people getting together, looking at images, reviewing images of the surgery, and talking with a pathologist face-to-face.

What we did when starting to formalize the program in 2018 here was get together every month and have basically a tumor board for placenta accreta spectrum. I know not every center's going to be able to do that, but we have learned so much from each other that I talked about how this is a problem that exists between specialties. It's amazing how much a surgeon can learn from a radiologist, how much a radiologist can learn from a pathologist, and how surprised some pathologists will be upon looking at the images of what a placenta accreta spectrum looks like in the body.

I don't think those same realizations, the same eureka moments would've happened in an email chain. I think they happened because we got together and started talking about what we were seeing. When we had the diagnosis wrong, why did we have it wrong? When we encountered difficulties during surgery, this is the reason that we had them. What can we do next time to avoid this?

I think there is a reason that tumor board has become so entrenched in cancer care ethics, because it's effective to get together face-to-face or Zoom face to Zoom face and talk through difficult cases. That's really what placenta accreta care is, difficult cases. They span multiple disciplines. That's my first suggestion to people. Find a champion, whatever subspecialty it is, and get organized enough to have periodic meetings.

At a less busy center, it might not be every month like we do it. It might just be ad hoc. When you have a case coming up, we're going to meet three weeks before the delivery date and talk through it. Anesthesia, NICU, radiology, obstetrics, gynecologic surgery, and anybody else that's going to be involved like urology or general surgery or trauma surgery for interventional radiology. I think that's the best way to really unlock a ton of great iterative team learning at your institution.

I think it also helps to centralize the number of people who are taking care of these cases. If you've got an oncology division of 12 people, it doesn't matter how busy you are. Each individual, one of those 12 people, is not going to see that many cases from year to year. My suggestion, based on what we've learned, is to try to get a smaller number of people really interested in taking care of these cases from the specialties that are involved.

For us, that looks like one surgically inclined general OB-GYN, two MFMs who have gotten additional training in surgical care of PAS, and then preferentially, we try to target a couple of the gynecologists who are most interested. The downfall of that is that if you have emergency cases and you don't have a good call system for that central team, then people who haven't seen this problem in a bunch of years try to scramble and take care of those people all of the time. If you're going to centralize care and only have a few people do the surgeries, I also think that those people should serve as a call team for accreta.

One mistake I made early on of being attending was to try to be that one person on call 365 days a year. Don't do that. Find a group of obstetricians who can help do that and find a group of backup pelvic surgeons who have a little bit more interest in this problem. I think that's the foundation of your call team as well as your surgical team for most of these cases.

[Dr. Amy Park]
Thank you so much for answering my questions. I find it fascinating and I don't know how many centers there are, but I think that here at the clinic, we're building an advanced complex pelvic surgery program within MFM. People who've had ileal conduits, for example, and are pregnant or I think that these things are all operational best practices. It's good to learn from people who've set it up and you learn the hard way like we all do.

(4) Diagnosing Placenta Accreta Spectrum

[Dr. Amy Park]
Anyway, I want to circle back to just making the diagnosis of PAS. How do you do it? Are there any biomarkers? Are you using ultrasound, MRI? How are you even figuring out early on that they have it?

[Dr. Brett Einerson]
How do we do it is a funny question because my first response is to say very poorly.

[Dr. Amy Park]
Good. There are some acupoints in this question.

[Dr. Brett Einerson]
I think it's very difficult. It's very easy to miss this diagnosis and it's very difficult to know exactly what you're getting yourself into before surgery. I think one of the disservices that our literature has done around this topic is to take highly specialized centers and patients who almost exclusively have extraordinary risk for accreta and get a bunch of ultrasounds and MRIs on it and say, "Oh, ultrasound and MRI are fantastic for making this diagnosis. 90% sensitivity, 95% specificity, positive predictive values and you're perfect."

That's not accreta care. That's not how it exists in the real world, but an obstetrician trying to figure out if they need to make their referral to my center does not have that same specificity and sensitivity of the imaging that they will get in routine obstetric care. It's a really difficult diagnosis to make.

We continue to be surprised when we're wrong about the severity of disease or the presence of disease, even at a busy place that's doing multiple cases a month. I want to just acknowledge that part because I feel like you should have a healthy skepticism about how good your tools are. That's important. I also think that people shouldn't feel bad when they get it wrong. Well, you're going to get it wrong, I'm going to get it wrong.

There's something missing from our current way of making the diagnosis that we haven't yet figured out. Maybe biomarkers will be fixed, but let me give you preamble now, I'm going to actually answer your question, Amy. I think it's helpful to split this into screening and diagnosis.

To me, it's very important for people to think about their role in general obstetric practice or even general ultrasound practice as screening for risk, not making the diagnosis with certainty. To me, it's very important to have a healthy understanding of risk profile, a high suspicion in patients with risk factors and a low threshold for referral to a specialty center for a second opinion.

If you're the average ultrasound practice not connected to a busy PAS center, I think your role with diagnosis really starts with the intake form. Does this patient have risk factors for placenta accreta spectrum? That is at least half the bat. If the person's got two prior cesareans and they have a low placenta, it almost doesn't matter what ultrasound findings you see, that person needs a referral and an expert to take a look at their placenta if it's low over the C-section scar.

To me, as I imagine the future of PAS care, I imagine ultrasound units really being screeners of risk factors at definers of placenta location. I think focusing too much on the individual signs like placental lacunae or myometrial thinning or bulging in the lower uterine segment or absence of the clear space or some of the modern rail signs or some of these really in-depth doppler findings. I think focusing on that is less important than defining the patient's risks and knowing the placental location, and in patients who have risk factors, I think referral on for diagnosis, the next phase, is what should happen.

[Dr. Mark Hoffman]
Who should get early ultrasounds, because in general, folks are getting scans at 18 or anatomy scans rather at 18 weeks. Certainly, people are getting dating scans early, but that's not everybody. Is there a population of patients-- like you said, screening history, who should we be sending?

[Dr. Amy Park]
Do we care about low-lying placenta 10 weeks when people are getting their anatomy screening or do we care about it at 18 weeks because it moves?

[Dr. Brett Einerson]
What's hard about this and you're getting at the reality that we're coming to see which is that the cesarean scar pregnancy and early placenta accreta spectrum are overlapping pathologies that have almost identical risk factors and very, very similar appearances. I have a slide set on cesarean scar pregnancy that basically a lot of them look like mini-accretas at 11 weeks. I'm a definite believer in what T-Board Trish preaches is that most cesarean scar pregnancies are baby accretas, early accretas.

[Dr. Mark Hoffman]
So that’s what I had heard is that that's the accreta before it becomes an accreta. That it's the spectrum of that disease, is that accurate?

[Dr. Brett Einerson]
That's our experience and that's what-- I think the best available case series are demonstrating. What's important about that and why I love your question about who should be referred and when is that there seems to be, in the cesarean scar pregnancy literature, a clear demarcation of beyond 9 to 10 weeks. The chance of hysterectomy in C-section scar pregnancy or early PAS is very high at the risk of less invasive and uterine sparing surgeries is much higher after 9 to 10 weeks.

If the United States had infinite resources, which we often pretend to have when thinking about screening. I would say that patients who have a prior cesarean, as part of their viability ultrasound, should aim to have that done at seven to nine weeks, and that an assessment of presence or absence of low implantation should be done.

Seven to nine weeks, again, I will reiterate, if we had infinite resources and an ability to know people were pregnant at an early age, then I would love for people to have an early assessment of low implantation pregnancy at that time. I still think there's a ton of work to be done on defining what low implantation is, defining what is CSP and what is not. That is not going to be disseminated anytime soon, but I think in the future people are going to recognize low implantation in patients with a prior cesarean as a significant risk factor for placenta accreta spectrum.

One reason that I think it's reasonable to at least consider, if you're going to get a viability to get comfortable with looking at the location of pregnancy in the uterus is that the outcomes are so much better for early treatment of CSP in that window. You can perform D&C or laparoscopic treatment or medical treatment and expect that that person's going to not have a major bleeding event, expect that that person will keep their uterus and be able to use it for a healthy pregnancy in the future.

Whereas if you wait until 11 weeks to get the ultrasound, that's already accreta, and the patient's likelihood of having a pregnancy where they avoid a hysterectomy is very low at that point, is much, much lower. It's possible in some settings but not as likely.

[Dr. Mark Hoffman]
That's my experience too, limited as the MIGS person at my institution for the better part of the decade. I had an MFM who had taken care of one early cesarean scar pregnancy, did a big ex-lap and it was this big and he goes, "That was stupid." Then he called me and said, "I want you to take care of it." I'd never seen one, so I called a bunch of people I knew. It was not a challenging case in hindsight, and having done a few more of those, I would agree they're not super technically challenging cases for those of us that do a lot of laparoscopy but diagnosis is one thing and it's challenging watching those things together.

(5) Best Practices for Placenta Accreta Spectrum

[Dr. Mark Hoffman]
It feels like you're watching a fuse on a bomb because you aren't sure what you're looking at but yet waiting longer, as you just told us, dramatically increases the risk to the patient. One of my big questions was how do we counsel our patients? Because sometimes you see a low-lying placenta, a niche and it grows up into the uterus, sometimes it turns out into what we're talking about here today. When do we intervene? When do we take that opportunity at seven, eight weeks to do something knowing that maybe it won't be an accreta?

[Dr. Brett Einerson]
To me, there's a ton of work to be done here. There's some interesting developing criteria for location of the early pregnancy in the start to direct us, but all of that stuff still needs to be validated. We are really oftentimes stuck in the gray, but for the cases that are less gray, for black and white cesarean scar pregnancies that are deep within the scar at less than 10 weeks, my recommendation for patients, because it's so deep in and because the diagnosis is clear, my recommendation to those patients is pregnancy termination. A fair number of my patients don't take that recommendation.

My experience has been, with six or seven cases now over the last five years, that all of those turn into terrible what we used to call percreta or FIGO 3, all of them turn into difficult cases. Some of them result in very, very early deliveries, even pre-viable deliveries. I have had patients who don't proceed with a recommendation, then go on to have a pre-viable delivery, and at that time, 18 weeks, they lose their uterus because there's not good treatment options.

My recommendation for obvious growth into the scar, low implantation, obvious cesarean scar pregnancy in the first trimester is termination of pregnancy by whatever local standard there is. Those standards differ. Sometimes it's injection, here it's suction D&C under ultrasound guidance with laparoscopic backup. That's been super successful for us. To me, that's one case where the risk of proceeding with pregnancy is considerable. The likelihood of taking home a baby that will be live-born and survive is lower and the likelihood of losing your uterus with expected management is close to 80% to 100%.

In the gray zones, it's much harder to counsel patients. If it's on the scar instead of in the niche pregnancy, cesarean scar ectopic at 10 weeks, or if you don't make the diagnosis until 15 weeks, it's very difficult to know what to do. I've had a lot of patients who come to me bleeding at 15 weeks, who look back at their images, they had cesarean scar ectopic, now they've got full blown, bad accreta and they're already bleeding.

I've counseled patients in that time period to have gravid hysterectomy because they're bleeding so much. I've had a few patients make it to viability or beyond in that group, but knowing an individual's outcome is beyond our abilities at this point. If there's not enough cases in the literature, there's not a good enough risk paradigm set up yet to be able to counsel patients well, aside from the obvious cases early on.

[Dr. Amy Park]
That's super fascinating because this whole dialogue about cesarean scar ectopic seems to be, like I said, just so much newer. This was not a discussion when I was a resident. Like I said, so many surgical videos, so much discussion, so much-- there is a gray zone and you've seen this develop over your experience. I'm so appreciative.

[Dr. Mark Hoffman]
And MIGS people and MFMs have to talk to each other now, which is a little uncomfortable at times. It's not great, but we do it. It's what we do for our patients.

[Dr. Amy Park]
Let me ask you about just what have you established in terms of best practices? I know that's an evolving area, but what's the optimal timing of delivery? Are you giving everyone steroids? Do you put them in the main OR instead of L&D, do you position them some way? Do you have a massive transfusion protocol ready? How are you managing all this stuff? Do you have IR and backup? How are you managing these patients?

[Dr. Brett Einerson]
Thanks for asking that. We have a protocol that we put together a couple years ago. It's iterative, it's updated every year basically to try to adapt to the evolving best practices. Our general approach is that we think our best practice based on the current literature and our experience is first of all to, like I said before, to have a pretty healthy skepticism that we are going to know about every case, and as such to overprepare even when we're not sure of the diagnosis and even when we think the diagnosis is more mild.

I can tell you that within our system in the last 10 years, I wasn't here for the whole 10 years, but looking back at some of our worst cases, they were cases of unclear diagnosis. "We're not sure that this patient has placenta accreta. Let's try to pull on the placenta," or, "This looks like a milder case. Why don't we try for uterine conservation or pulling on the placenta?" Those are some of the actual worst cases.

I think optimal care really starts with a low threshold to over prepare. Meaning, having them done at a time when you can have surgical backup, having enough blood available in the room, having the team ready and not just relying on your response to unexpected cases but to over prepare even in cases that are a little bit borderline. That's a philosophical point.

We see these patients throughout pregnancy, we get an ultrasound about every month to take a look at the placenta. In our experience, the placenta doesn't continue to grow into organs. It's established by 20 to 24 weeks how severe it's going to be. Then depending on the individual's characteristics, we start having them see our anesthesiology team to prepare for that. Having them see the pelvic surgeons who are going to be involved in their care. Getting familiar with our labor and delivery triage in case they have a bleeding event. We introduce people to all of the team members who are going to be involved in their care.

For patients who have bleeding during pregnancy, we have a pretty low threshold to admit though, because our experience is that one bleeding event often leads to an unexpected delivery. We have a pretty low threshold to monitor people beyond what we would otherwise monitor people for preview with bleeding. I've had patients, unfortunately, who spent most of their pregnancy in the hospital. Delivery timing, our approach with that is to usually follow the guideline that's put forward by ACOG, which is 34 and 0 to 35 and 6. Although I will say that even the ACOG guideline says that the optimal delivery time is unclear.

Internationally, there are a lot of people who are pushing for a later delivery, 36 to 37 weeks in well-selected patients. In some patients, they have been very stable, they don't have a lot of uterine activity. They live very close to the hospital. Maybe they don't have a placenta previa. They're highly motivated to deliver later. We will aim for 36 to 37 in those patients. We individualize it and if it's a sure case and there's anything that the patients are having in terms of uterine contractions, bleeding at all, we typically aim for that 34 to 35 and 6-week window.

[Dr. Mark Hoffman]
Just hearing you talk, the number of cases you've done, the nuance between each case and how individualized you're able to be with each case, case by case. Like you said, if you're doing a couple of these a year, if you're doing a handful a year, there's no way, and without an abundance of literature, this is where experience can matter maybe as much as in any place in medicine and what we do in obstetrics in general.

Not as much research as we'd like, but in this area, just hearing you talk and how you'd be able to counsel patients, "Oh, well I've been doing this for years. I've seen this many--" Well, I'm going to listen to whatever you say as a patient as opposed to like, "Well we're just going to see how it goes." I'm just getting a window into the value and the power of having a center like yours.

[Dr. Amy Park]
Do you give everyone steroids based on your experience, or obviously if they have a bleeding event or uterine contractility or what have you?

[Dr. Brett Einerson]
I try to save the steroids up until the time that delivery seems fairly imminent. Certainly if somebody comes in at 28 weeks and has a liter blood clot or we’re wondering whether or not they're going to get delivered, they get steroids. Most cases, we hold off until a week or two before delivery. Since we're aiming for that 34 to 35-week time period, it's right at that cusp of traditional antenatal steroids and ALPS. We are typically administering steroids around that 33-week time period if all is going well in their pregnancy.

Mark, I think to add on to what you were saying or to throw in my 2 cents on that, I think for other types of serious health problems, and I think this is a serious health problem, it's evident that you get a second opinion. It's evident to patients and to doctors that you go to the place that does more of them. My dad got cancer living in rural Minnesota when I was a first year fellow. At the risk of offending the University of Minnesota, another healthcare system is like when you get cancer in Minnesota, you go to Mayo. I'm not saying Mayo has something hyper special there, but patients know you have a serious diagnosis to do it to the place that has the name for taking good care of patients.

[Dr. Mark Hoffman]
I'm in Kentucky and I've spent time working in rural Eastern Kentucky. We had a rural eastern Kentucky doc on the show because I think the work that they do is invaluable and not to do anything but to give them credit. That being said, when you're dealing with things like this that are incredibly rare and in your case potentially incredibly catastrophic, volume matters.

In terms of proximity, are you having folks move to Salt Lake City? What can you do to get social support? Because one of the big things I've learned working with the population of patients that live remotely and live rurally, access is-- you can know the right answer, you can check the right box, but if they're 120 miles down country roads away, it doesn't matter that you know the right answer. What measures are you guys taking in Utah to solve some of those social determinants of health, the proximity issues?

[Dr. Brett Einerson]
Yes, so thank you for that. The best study on how unpredictable delivery can be for patients is, I think, comes from Baylor where they show that about 35% to 45% of patients, depending on the year, delivered before their expected delivery time, placenta accreta spectrum and many of them weeks and weeks beforehand. It's a particular challenge for those of us taking care of accreta to not only be ready 24/7 but also to not take substantially worse care of our patients who live four or five hours from the hospital.

That's inequitable. If we don't have systems set up to help those patients financially, then we're being inequitable with our care. It shouldn't be the happenstance that if you live in my area code that you get much better care than if you live in rural Idaho. What I will typically do when we make the diagnosis, oftentimes in the middle of the pregnancy, is to have a conversation or communication with the home doctor and give them the expectations for what things I want to see the patient for and do co-management up until about 30 weeks. Then sometime between 30 and 32 weeks, I ask patients who live more than 45 minutes from the hospital to make arrangements to come to live in Salt Lake City.

For some patients that means a family member. There's a lot of large families in Utah, but for many patients, that's taking up residents at Ronald McDonald House. We, unlike a lot of other centers that I've heard from, actually have really amazing support for pregnant people at Ronald McDonald's Center.

[Dr. Mark Hoffman]
I was going to ask because I don't think of the Ronald McDonald House as being a place where people stay who are still pregnant. Talk about what makes that special or how that came to be.

[Dr. Brett Einerson]
I think it existed prior to my coming onto the scene in Utah. It wasn't something that I had to set up personally. I think it was a realization on the Ronald McDonald House that so many patients, whether it was due to a complicated fetus or complicated mom, were going to end up in their hands anyways. We're not as landlocked in Salt Lake as we were in Chicago where I know that Ronald McDonald had maybe a little bit stricter criteria for who could be there. We have, I think just out of good relationships and good luck, had the good fortune of Ronald McDonald being able to house these patients with placenta accreta spectrum or other anticipated fetal and maternal prematurity-related needs.

Its prematurity is the key that unlocked our ability to have patients around Ronald McDonald, and as long as they have another adult with them, they're able to stay there. For patients who don't, and a lot of them don't, our hospital has arranged for basically sliding scale type housing at one of the very local hotels or will set them up in an apartment depending on their unique needs. For patients who prefer something different, I've had patients who do other things like stay in their RV at an RV park and it's 20 minutes from the hospital. RV life is big in Utah.

(6) Placenta Accreta Spectrum Morbidities

[Dr. Amy Park]
That's pretty cool. We've alluded to the education and support these patients need, but what are the health outcomes and their quality of life? Is the main morbidity associated with PAS? Is it maternal? Is it neonatal? Is the most morbidity, neonatal morbidity related to prematurity? How does that all work out?

[Dr. Brett Einerson]
Those are good questions. What I tell patients is that placenta accreta spectrum is a problem that keeps most of us up at night for the maternal morbidity risks. Even in modern cohorts for patients with severe placenta accreta spectrum, so closer to the percreta or the FIGO 3, there's a real risk of maternal death during treatment and usually that's from bleeding. Those occur if you practice placenta accreta surgery long enough, you're going to have a maternal death, unfortunately.

To reassure patients, I tell them that those risks are generally thought to be less than 2% to 3% for even severe cases of placenta accreta spectrum. There's the risk of ICU admission if you get a massive transfusion, bladder injury is pretty common like 20% roughly of cases, ureteral injury may occur in 5% to 7%, and so there's significant surgical morbidity from a maternal standpoint.

The neonatal morbidity is really almost exclusively related to prematurity. That's one of the reasons that international colleagues of mine are really interested in pushing deliveries to later because thankfully, sort of astonishingly, this placenta that's not living where it's supposed to and that looks totally nasty in some cases, is actually doing a really good job of taking care of the baby. Fetal growth restriction is not associated with placenta accreta spectrum like you might think it might be.

Congenital anomalies are not associated as far as we know. To me, that's a further reason that it's not a placental problem. That it's a uterine problem, but that's my soapbox. What I try to give patients reassurance about is that it's our job to figure out the right balance between reducing the risk of prematurity over time and not putting you at too much risk for catastrophic bleeding events. Because the worst cases, the scariest cases, the ones where we bring otherwise healthy people to the brink of death are the ones where they come in and they're one or two or three liters down already and getting massively transfused before we can even get the baby out or start the hysterectomy.

The delivery timing question is an important one to keep investigating. For that very reason, we're always, just like my entire job, always balancing what are oftentimes competing maternal and fetal risks. Then I would be totally remiss if I didn't talk about the psychological aspect of this. We have all, until this point, until maybe three to five years ago, almost completely in the literature ignored the psychological toll of placenta accreta spectrum.

(7) Postpartum Treatment & the Emotional Toll of Placenta Accreta Spectrum

[Dr. Brett Einerson]
I gave a talk a couple of years ago and said, this is the most pressing current issue that's not being addressed in placenta accreta care. We've been so laser-focused and rightfully so, on keeping moms from dying, keeping cases from getting to the point of massive blood loss that we have not done as good of a job as a field, in my opinion, of addressing the anticipation of anxiety associated with PAS and then post-delivery care for the psychological fallout and long-term outcomes that are really pretty bad associated with this.

I actually did a study at the end of my fellowship with a medical student named Brian Grover that just asked patients how they were doing at 6 months, 12 months, 24 months, 36 months, out all the way, some to 5 years. We asked them how they were doing from a psychological and health standpoint. Compared to people who were having a third or fourth C-section but didn't have accreta, patients with placenta accreta spectrum who underwent hysterectomy had two to five times the risk of pelvic pain, difficulty with sex, anxiety, and depression, postpartum grief and loss, decreased quality of life on quality of life surveys.

It's incredibly important for us to acknowledge that the morbidity does not end if we avoid the ICU or discharge that person home from the hospital. The morbidity continues on well beyond that. There are other studies out there by Toll that suggest that PTSD-like symptoms are incredibly common in patients that fits with my experience. There are logistical postpartum problems with coordinating, with sending a person back to Montana where their gynecologist doesn't really know what's happened and having them get postpartum care. It's an incredible challenge and an incredibly underappreciated challenge, I think, taking care of these patients long term.

[Dr. Amy Park]
I agree. The PTSD in UroGyn about fourth-degree tears, anal sphincteroplasty, all that stuff. There's like a lasting sequelae. Interestingly, there used to be this person who was quite active. It used to be called Mothers with Fourth-Degree Tears, but now it's called something differently to be more inclusive. She just struck a chord with how many people out there were suffering from PTSD after this traumatic delivery event.

Losing your uterus and having a preterm delivery and living somewhere away from your family for a couple of months, it's a lot of stuff going on. That is incredible. I can see that as being a huge need to study because it's not really well understood. At least you're making the inroads into it. I wonder if it's also a little cultural, like are there international studies looking at this too?

[Dr. Brett Einerson]
Honestly, the best studies on patient experience related to placenta accreta spectrum are from Ireland. A person who I've gotten to know pretty well, Helena Bartels, has done a ton of work on this in Northern Ireland to try to assess the patient experience and long-term outcomes associated with placenta accreta spectrum. The things that their patients say in their quality of studies are the same things that our patients are saying in Utah. If we had a larger sample, I feel confident that patients in rural Kentucky and patients in Cleveland, and patients in suburban Los Angeles would be saying a lot of the same things.

My challenge to people who are taking care of placenta accreta spectrum is that if you don't think this is a problem, then ask your patients, check in with them 12 months from now. I guarantee that even if you've been the best doctor that you can possibly meet, even if you've reduced morbidity to the maximum extent, your patients were still terrified by this problem.

I had a patient who talked about writing letters to her kids because she was worried that she wouldn't make it through surgery. I had no idea that she was going through that. I was confident that we were doing the best possible care that we could do for her. I was totally blind to the fact that she was so psychologically distraught that she was worried about just coming out the other side. We've completely changed the way we address the psychological needs of our patients because we were so moved by our patients and what they told us, they were appreciative of their care and they also felt like they needed so much more help psychologically and emotionally.

[Dr. Mark Hoffman]
It's a testament to you as not just a physician, but also as a person to look at your patients as people because you clearly have a great deal of talent and brains and logistical and administrative abilities to put a program like this together, but you can forget. There's so many things you just-- well if it just goes well, then everything else is someone else's problem, but taking the extra steps and to think about it in those terms is something we all don't do as well.

I won't speak for others, but I know that there's times when I've been very grateful to have had some patients who were willing to share their experience with me, that you went the step further and asked the questions to others so we could have some data so we could have a conversation so we could understand how to change practice and which sounds like you've done in Utah.

Kudos to you and your patients are extremely lucky to have you and we're all lucky to have now the opportunity to hear from you and understand more about not just the diagnosis and management, but the whole, you say spectrum. I think I've just now expanded my definition of the accreta spectrum. It's all the way through the postpartum and to the social and emotional side of it too. Great work.

[Dr. Amy Park]
Absolutely. Thank you so much for coming, Brett. Every time I hear you talk, I learn so much about PAS, but also just how to be a better doctor. I'm appreciative of your time. Both of us are, and that's what just makes us so special, and hopefully, our listeners get to glean some insights and wisdom from everything that you've said.

[Dr. Mark Hoffman]
And we will share some of the inspiration you've given to us tonight for sure.

[Dr. Brett Einerson]
Well, it's been a pleasure to talk to you. I really appreciate the opportunity.

Podcast Contributors

Dr. Brett Einerson discusses Placenta Accreta Spectrum (PAS) on the BackTable 25 Podcast

Dr. Brett Einerson

Dr. Einerson is an assistant professor of OB/GYN in the division of Maternal Fetal Medicine (MFM) and Director of the Utah Placenta Accreta Program at the University of Utah.

Dr. Amy Park discusses Placenta Accreta Spectrum (PAS) on the BackTable 25 Podcast

Dr. Amy Park

Dr. Amy Park is the Section Head of Female Pelvic Medicine & Reconstructive Surgery at the Cleveland Clinic, and a co-host of the BackTable OBGYN Podcast.

Dr. Mark Hoffman discusses Placenta Accreta Spectrum (PAS) on the BackTable 25 Podcast

Dr. Mark Hoffman

Dr. Mark Hoffman is a minimally invasive gynecologic surgeon at the University of Kentucky.

Cite This Podcast

BackTable, LLC (Producer). (2023, June 15). Ep. 25 – Placenta Accreta Spectrum (PAS) [Audio podcast]. Retrieved from https://www.backtable.com

Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.

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