Postpartum and Post-miscarriage Sonography of the Pelvis - SD

Introduction

Hi, I am Douglas Brown.
I'm from Mayo Clinic in Rochester, Minnesota,
and we're gonna be talking about ultrasound in the
postpartum and post miscarriage patient.

Hey, we're gonna be talking about,
pelvic ultrasound in the postpartum
and post miscarriage patient, today.

The main things we're gonna talk about are diagnosis
of retained products of conception,
both in the first trimester patient
and the postpartum patient.
We'll talk about the imaging criteria that you can use
and the limitations of those criteria.
And then we'll look at a few other postpartum issues,
particularly the post cesarean section patient
and some unique imaging findings
related to those patients.
And then a few other miscellaneous topics.

Diagnosis of Retained Products of Conception

At the end, patients who present with abnormal bleeding
and the postpartum
or post miscarriage, timeframe,
we generally are most concerned about retained
products of conception.
We do a lot of ultrasounds for this reason.
And you think it would be very obvious what we could use.
But actually if you, when you look at the literature,
it's difficult to find reliable predictors
of retained products
of conception based on ultrasound features.
Variable features have been assessed, including thickness
of the endometrium area, the appearance of morphology
and doppler findings.
The criteria seems somewhat vague in many of the studies,
and it's also worthwhile to note
that the different studies have used different endpoints.
Some have used pathology,
and you may think that's great,
'cause that does give you definitely whether there's
retained products of conception or at least more likely to
however others have used clinical outcome.
And it may actually be that clinical outcome's more
important because what we often wanna know is whether
that patient needs an intervention,
whether they need surgery.
And even if there's a small amount of retained products
of conception that would be evident on pathology, if
that patient's gonna pass them
and do well with conservative management,
that's probably the more important thing.

Post-Miscarriage and Postpartum Scenarios

So we're gonna consider the post miscarriage
that is in the first trimester
and the postpartum scenarios together.
There's less published on the postpartum patient alone.
Most of the postpartum studies limped the post
miscarriage patient that is the first trimester together.
There are some studies that concluded just the first
trimester, but we're gonna lump them together.
And when it's important, I'll specify,
if, criteria apply more to one or the other.

Retained Products in the First Trimester

So what about retained products
of conception in the first trimester?
Well, a case like this, where you have a,
gestational sac in the uterus,
those are easy, easy to diagnose.
We know they're still retained products of conception.
So, otherwise
what we're looking at is what's usually
referred to as the endometrium.
I put that in quotation marks
'cause it's often not just the endometrium
that we're looking at anymore.
It may be retained products or it may be blood products.
But it's still often referred
to in the ultrasound articles as the endometrium.
So we can look for a mass, we can look at thickness,
and we can look at doppler findings related
to the endometrium
and endometrial mass, as in this case,
transabdominal scan sagittal view.
We see a focal hyper coic mass,
different patient transvaginal scanning,
focal hyper coic mass in the endometrium.
These are most likely due to retain products of conception.
Could still be clot, occasionally, can look this way.
And this finding actually seems more predictive in the
first trimester than in, in the postpartum patient
to identify retained products of conception.
So this is probably the most useful finding
for identifying retained products,
but still has its limitations for this hyper coic,
mass discrepant results have been reported,
several studies in the postpartum patients reported
as a common normal finding, particularly in the first one
to two weeks postpartum.
Other studies have found it to be a better predictor.
Sauna histogram could be used.
It makes sense if you did a sauna histogram
and you see a free-floating mass in the cavity.
Most of those would probably do well
with conservative management based on one study.
Whereas if you see attachment to the wall,
those are more likely due to retain products.
Certainly seems reasonable.
There's not much in the literature about it
and it probably, it's really hasn't caught on,
as the way to evaluate for retained products of conception,
even though it could be helpful in selected cases.

Endometrial Thickness

So a question. What endometrial thickness best discriminates
the presence of retained products of conception?
Is it 2, 5, 10, 15 millimeters or we don't know?
Well, we actually don't know what number to use,
to discriminate patients with
and without retained products based solely
on endometrial thickness.
So now we're talking about the patient
who does not have an endometrial mass,
but you're just basing,
the assessment on endometrial thickness.
You know, here's a patient with a retroflex uterus,
very thin endometrium, three millimeters, another patient
with 13 millimeters.
Obviously I think we're gonna be more concerned about this
patient with a 13 millimeter endometrium rather than the
three millimeter endometrium.
But what number can you really depend on?
Cutoff values from five to 20 have been suggested,
but actually if you look closely, there's a lot
of overlap in most of the studies.
And many studies that have looked at management
of these patients have pricked an arbitrary number
for endometrial thickness.
They have not systematically,
evaluated which,
endometrial thickness is most useful.
So when you compare it with pathology,
that is endometrial thickness with pathology,
there's really no reliable cutoff.
Again, different numbers have been looked at.
In this one study from 2007,
the best number was actually eight millimeters
with a sensitivity of 87%
and a specificity low of 21%.
Morphology is probably important in these patients,
but it wasn't evaluated,
in this study.
If you base it solely on pathologic correlation,
you can virtually never exclude
retained products of conception.
Retained products have been reported on pathology, even
with a thin endometrium of less than two millimeters.
Another study that I like to reference,
and depend on is,
an older study from 1993.
And in that study they found
that at the endometrial thickness is
less than 10 millimeters.
Most of the patients do well without dilatation
and gerage based on clinical outcome.
And again, I think that might even be more important than
using pathology as the gold standard.
So this study found 10 millimeters,
another one eight millimeters,
but really the best cutoff
for deciding expectant management in these patients is
still not currently known.

Doppler Ultrasound Findings

So what about doppler ultrasound? 'cause that help?
It certainly seems reasonable if you see flow in a mass
or in the thick endometrium, it is more likely
to be retained products of conception.
Here's a patient with focal mass color
Doppler imaging shows flow.
And this did have retained products.
However, here's another patient.
Thickened heterogeneous endometrium, no flow detected yet.
There was still retained products
of conception at pathology.
So presence of flow certainly favors retained products,
but no detectable flow while favoring clot does not exclude
the presence of retained products of conception.
There's another study that looked for retained products,
using doppler findings.
163 patients, second, third trimester delivery,
colored doper was performed in 29 of the patients.
16 of them had retained products,
12
of which had endometrial flow by doppler imaging.
And four did not. 13
of the patients did not have retained products.
Seven still had endometrial flow and six did not.
So there certainly was a trend toward flow being,
equated with retained products,
but it was not statistically significant in this study.
Another study using path, and it was a mix of postpartum
and post miscarriage patients.
They had 28 patients with retained products. Seven without.
82% of the patients with retained products
of the conception had flow identified by Doppler imaging.
No flow can be seen in either,
and they had one case without retained products
that still had mild flow.
So it seems that endometrial flow, especially when equal
or more vascular than the myometrium, does seem
to favor retained products of conception.

Complex Fluid and Heterogeneous Material

Now, occasionally you run into patients
who don't have a focal mass or they don't have thickening,
but you just see this complex fluid has internal echoes
or it's heterogeneous material
and it's hard to tell what's going on.
These are two different patients, neither
of which had retained,
placenta
and the postpartum period.
Now, this complex fluid
or heterogeneous materials a bit problematic
'cause the terminology varies
and we really have no consistent terminology
to describe these Varying significance has been reported.
It seems that this complex fluid
or heterogeneous material is usually not due to placenta.
Placenta tends to be more homogeneous, hyper coic,
again, not totally reliable,
but can at least,
suggest
that if it's more heterogeneous it's less likely
to be retained placenta.
And the other thing you can look for when you see this
appearance is either spontaneously
or maybe with a little transducer pressure.
If it's just complex fluid, you can see some motion of
that fluid,
while you're imaging.

Post-Surgical Treatment Patients

Now what about patients who've already
had surgical treatment?
What we've talked about so far applies to the patient
who has been pregnant, then have bleeding.
And the question is, does she have retained products?
Sometimes that's already happened.
They've gone on to A DNC and then they're still bleeding.
And we have to decide is there still retained products?
Well, in this study within the first week
after A DNC, it almost always looks abnormal.
74 patients, all of which did well,
about a, a
fourth of them had a thin endometrium defined in that study.
As less than seven millimeters, 50% had a seven
to 19 millimeter endometrial thickness.
And about another quarter
of the patients had greater than 19 millimeter thickness
of the endometrium or heterogene heterogeneity.
And again, all these patients did well.
So we might be particularly concerned about this ladder
group with more than 19 millimeters or heterogeneous,
but maybe even this middle group.
So most of these patients, it looked abnormal.
They still did well after A DNC.
So it looks like even in these patients,
or particularly in these patients,
you cannot rely on ultrasound alone to decide
who needs further,
intervention.
You probably need to follow them up,
with ultrasound,
in many cases, wide overlap in the ultrasound findings
of symptomatic and asymptomatic women.
After surgical intervention,
most features did not discriminate.
Neither the appearance nor the doppler findings.
Endometrial thickness,
was a little thicker in symptomatic patients
with still a lot of overlap.
And in this study, they concluded that asymptomatic women
after termination of pregnancy often have thick
heterogeneous endometrial contents
with flow by doppler imaging.
And that that does not necessarily equate
to retain products of conception.

Approach to First Trimester Patient

So my approach to the first, at least first trimester,
patient with question of retained products of conception is,
if you see a gestational sac, then it's easy, you know,
there's retained products,
but that's usually not the easy case.
So if you do not see a gestational sac, the ultrasound tends
to indicate the amount of material,
but it's more difficult to tell what that material is.
If you see extremely thin endometrium,
it's less likely retained products.
So I think we're better with ultrasound at determining
that the uterus is empty more problematic when there's
something in the uterus to tell what it is.
It seems at this point
that an endometrial mass is probably the best predictor
of retained products of conception,
but seems to have low sensitivity.
This is probably more useful.
That is endometrial mass is probably more useful in the
first trimester, less useful in the first two weeks
postpartum when you can see this more as a normal finding.
As far as doppler findings,
the data is still somewhat sparse, reliability unclear,
but certainly it seems that there's at least a trend
that if endometrial flow is present, retained products
of conception are more likely no flow detected
by doppler favors clot, but could still be retained.
Products of conception if you don't have a mass
but you're only going by endometrial thickness,
I currently use 10 millimeters.
Eight might be reasonable also to say
that clinically significant retained products
of conception are unlikely.
And that's how I tend to report out these cases in these
patients, that if it's less than eight to 10,
I currently use 10.
But it would be hard to argue which is more reliable,
that if it's less than about 10 millimeters,
I say clinically significant retained products
of conception are unlikely.
Doesn't mean that there's not a little bit
of retained products, but at least based on some data,
it seems that these patients,
tend to do well
with conservative management.
If it's more than about 10 millimeters,
then I think it's problematic.
I would use color power doppler to push me one way
or the other with flow favoring retained products, lack
of flow, favoring clot, but again, neither totally reliable.

Postpartum Period

Now what about the postpartum period?
Let's talk a little bit about the normal postpartum
uterus, C-section patient
and a few other miscellaneous abnormalities.
We've already talked about retain placenta, retain products
of conception in the postpartum period.

Scanning Postpartum Patients

One thing they mentioned is how do you scan
these patients postpartum?
Well, even though most pelvic ultrasound,
currently involves transvaginal scanning,
you generally don't need this,
at least in the first two weeks.
Postpartum transabdominal scanning tends to work quite well
and the majority of patients in the roughly first
approximate two weeks postpartum, the uterus is still large
displaces bowel, it transmits sounds easily,
and it's just gonna be more comfortable for the patient.
After about four weeks postpartum,
you probably are gonna need the transvaginal scanning in
many patients and those intervening two to four weeks,
I think you just have to take it on a case
by case basis depending on
how well you're seeing abdominally
and patient comfort issues.

Normal Postpartum Uterus

The normal postpartum uterus in the first few days can still
be soft, can still be easily distorted
by the transducer here.
Here's the transabdominal scan sagittal.
And you can see we can actually deform the anterior surface
of the uterus easily with just transducer pressure.
Contractions can still occur.
We know uterine contractions,
that is
of the myometrium a common during pregnancy
and they can still occur in the early postpartum period.
The other thing I've noticed in the early postpartum period,
and here's a patient four days, is
that the inner myometrium can be hyper coic,
more hyper coic than we're used to.
And here's a patient at eight days so much in fact
that sometimes, at least on first look, you may wonder
where the endometrium is.
Is it just this thin area? Is it all of this?
But if it's all of that, that's quite thick.
And the same thing here. But this is just the inner
myometrium and I've just noticed
that in the early postpartum period,
it can be hyper coic more so than usual.
It may even occasionally give you trouble deciding
where the endometrium is located
later in the postpartum period.
Ute is certainly gonna decrease in size.
The most rapid decrease in size
is the first one to two weeks.
And the size of the uterus is typically back
to its non grave size by 68 weeks postpartum,
with no
effect from breastfeeding on that return,
size return.

Postpartum Hemorrhage

Now the area
where ultrasound can often help in the
postpartum period is hemorrhage.
The definition
of postpartum hemorrhage is more than 500 ccs blood loss
after a vaginal delivery
or more than a thousand ccs after cesarean.
It's usually separated into primary
or early postpartum hemorrhage, which is typically defined
as hemorrhage in the first 24 hours and then secondary
or late postpartum hemorrhage as
that occurring 24 hours
to 12 weeks postpartum.
The most common causes,
are these uterine A acne is certainly the most common cause,
particularly a primary postpartum hemorrhage,
retained,
placenta or even you can occasionally get,
placenta accreta postpartum,
is certainly a cause also
and often a reason that ultrasound is performed.
This is a little more likely in the secondary postpartum
hemorrhage, but also can occur with primary.
And then the other cause is to remember a trauma
that is lacerations to the cervix, vagina, or perineum.
Occasionally uterine rupture though not very common.
And then coagulopathies can also be a cause
of postpartum hemorrhage.
We don't typically need it for hematomas due to lacerations,
but you may occasionally see it.
Here's a sagal view of the cervix.
Here's a hematoma in the cervix,
from a cervical
laceration, but we don't typically need ultrasound
to make that diagnosis.

Uterine Rupture

Uterine rupture,
historically in the literature has been difficult to see.
We've often depended on secondary findings
of intraperitoneal fluid.
Occasionally you can actually see a cleft in the
myometrium from a uterine rupture.
I think we're getting better at seeing that,
with ultrasound.
But you may have trouble visualizing the,
direct side of the defect in some
patients with uterine rupture.

Retained Placenta in Postpartum: Additional Findings

We talked about retained placenta in the postpartum period.
In ultrasound findings.
We talked about this earlier with mass thickness
and Doppler findings and wanted to mention a couple
of other things that you may encounter more frequently in
the postpartum patient than in the post miscarriage patient.
One is fluid only.
Anti coic fluid, like this is not in common
and does not typically mean retain the placenta
and will usually resolve on its own.
The other thing you may occasionally encounter,
it's not very common in my experience,
but certainly not rare either, are these little hyper coic,
tiny echogenic foci in the endometrium.
This is usually air.
It's been shown that air can persist
for several weeks postpartum.
It can be normal or due to endometritis.
These echogenic foci, as long
as you do not see them within a mass, are usually not due
to retained products.
So I typically, when I see these try
to decide are they just kind
of random scattered in the endometrium?
Are they within a mass of tissue?
If there's no mass, it's probably just air,
and it's probably not retained products.
Theoretically, if these were very extensive air,
it could obscure some retain placenta.
But
I think that's pretty uncommon.
If you see it within a mass as in this case, here's a mass
with these echogenic foci, then that is more concerning
probably is calcification.
And it could be mature placenta,
with calcification
that's retained postpartum
'cause we know that the placenta does,
during pregnancy
and the later part of pregnancy have more calcifications.
Or perhaps if it's been retained for a long time,
even postpartum, you could get some more
dystrophic calcifications.
So I get more concerned about hyper coic foci if there's an
endometrial mass, more likely
to indicate retained placenta in those cases.

Serum Beta HCG

What about serum? Beta HCG?
Probably can't rely on totally.
There was a small number of cases in this study.
And you can have pretty low HCG levels.
About half the patients had low, very low to no HCG levels.
So probably cannot depend on serum H CG
to exclude retained placenta postpartum.

Post-Cesarean Section Patient

Now we'll move on to the post crean section patient talk
about some normal findings
and talk about some of the hematomas we can see there.

Low Transverse Incision

The low transverse incision is
by far the most common location
of the hyster otomy that's performed.
It's a horizontal incision in the lower uterine segment.
These have a lower risk of hemorrhage, infection
and later rupture.
What do we see? Well is a patient transabdominal scanning
four days after cesarean section
and you see a few little small echogenic foci,
a little subtle mass like area.
There's a different patient two weeks postpartum.
This one is transvaginal.
So now the anterior lo segment is here
'cause this is a retroflex uterus.
So we see a few little hyper coic foci.
These are probably the sutures.
And this is essentially a normal finding
to see a subtle hypo coic area.
With echogenic foci,
it's usually less than about two centimeters.
There's no hard and fast size cutoff,
but it's usually less than about two centimeters
as a normal finding,
in this so-called bladder flap area
in the lower reader and segment.
If it gets larger and there's no hard
and fast number again, it's usually more than about two,
maybe three centimeters if you see a mass like area there in
the region of the C-section scar.
And here's an older case,
a distinct mass like area anterior segment.
These are typically referred to as bladder flap hematomas.

Classical Incision

Now there's still a few patients
who have the old classical incision for their hysterectomy.
For a cesarean section, it's a vertical
or longitudinal incision higher up in
the body of the uterus.
It's used in some emergency cases.
Sometimes it's difficulty performing the,
the lower uterine segment incision.
So not frequent, but you may still occasionally see patients
after a classical hysterectomy.
Now what do these look like? There's not as much,
published about these, but here's a patient
six weeks postpartum.
I'm sorry, yeah. And post cesarean section with bleeding,
vaginal ultrasound, sagittal view of the uterus.
We have one of these kind of mid position uterus
where the fundus is directly away from the probe.
And we see this area of heterogeneity kind
of in the anterior myometrium and a little bit here too.
And we we're concerned at first, you know,
is this some retained,
placenta, but in fact,
mr
and the same patient T two weighted image received virtually
nothing there on the spoiled gradient.
Echo images we're seeing,
susceptibility artifacts probably related to the sutures,
from the classical hysterectomy.
And there was no re evidence
of retained placenta on mr are on
follow-up imaging in this patient.
So this seems to be normal,
for a patient
after classical hysterectomy.
Here's another patient four weeks post cesarean section,
sagittal view of the uterus.
We're not getting all the way up to the fundus,
but you can see some epigenic foci in the
anterior myometrium.
And on this video clip, I think again,
you can see multiple small hyper coic foci in the
anterior myometrium.
This was due to the classical hysterectomy, probably due
to the sutures,
used another location.

Other Hematomas

You can see hematomas,
besides bladder flap is a so-called sub fasci hematoma.
They tend to be more anterior, often anterior
to the bladder in the pre vesical space.
So if you're not seeing this area well with your usual,
vector or curve probe,
you might even consider a linear probe looking more
superficially,
to look for these subfascial hematomas
as another one, a larger subfascial hematoma.
So remember, look more anterior, look superficial,
and if they're small, you may overlook these,
and consider using a linear transducer,
if you're suspicious, but not seeing this area well.

Miscellaneous Topics

Now, a few other miscellaneous things, A few
that are uncommon causes
of bleeding in a postpartum patient,

Placental Site Trophoblastic Tumor

placental site.
Trophoblastic,
tumor is probably the least common form
of gestational trophoblastic disease.
It can follow any type of normal
or abnormal pregnancy, though usually it's
after a full term pregnancy.
Patients usually have vaginal bleeding,
not always, but usually.
And it can be anywhere from weeks to years after delivery.
It's even been reported up to 14 years after delivery.
Patients may or may not have a amenorrhea.
These tumors are composed of intermediate trophoblasts.
So the HCG is usually normal to only mildly elevated.
And there's actually another marker.
Human placental lactogen that's often increased in this type
of trophoblastic tumor.
They have variable biologic behavior.
They're less chemosensitive than other forms
of trophoblastic disease and may require hysterectomy.
They have a malignant behavior clinically in about 10
to 15% of patients.
So the ultrasound appearance,
is variable.
It can involve the endometrium and or the myometrium.
Here's a patient with heterogeneity cystic looking space
in the myometrium on this transverse view
with doppler imaging.
You see pretty abundant low resistance flow in this region.
Pretty vascular low resistance.
You might even be thinking about an A VM,
but in this case, this turned out
to be placental cyte trophoblastic tumor.

Placenta Accreta

Another thing to remember is placenta accreta.
We often get more concerned about this
and during obstetric scans,
antepartum
or even intrapartum patients are having bleed bleeding.
But occasionally it can actually present
in the postpartum period.
And here's a patient with this hyper coic mass,
not just an endometrial mass, but actually seems to go out
and extend almost to the serosal region
of the uterus in this postpartum patient.
And this is retained placenta in creta
retained placenta.
Mr. May help, but the incremental value over ultrasound,
even in the postpartum patient is not clear.
It might be more helpful in the postpartum patient
actually, because we could give gadolinium
to these patients, whereas we wouldn't typically do
that in the,
obstetric patient who's still pregnant.
The, the potential problems I've encountered are,
it can still be hard to tell what's thinning
of the myometrium for from just invasion.
And even with myometrial vascularity,
in that region
of thinning, it can still be difficult to tell.
Here's a patient,
postpartum placenta accreta T two weighted image,
high signal intensity mass.
We thought the myometrium here was just quite thin.
Here it is after gadolinium.
But hysterectomy was performed in this patient
and she did have placenta accreta.
She did have the mild form placenta, crete vera,
but we interpreted this as thin, whereas,
pathology,
it was actually invaded.

Low Resistance Arterial Flow in Myometrium

So another question. Low resistance arterial flow in the
myometrium of a postpartum
or post-abortion patient is abnormal indicating retained
products of conception or an AAV m True or false?
Well false.
What we know is
that you can occasionally see this as a normal finding.
So a little background,
'cause we may be thinking about uterine a
VM in such patients.
Most uterine AVMs are required due to trauma,
often from dilatation and tage.
It's not necessarily postpartum
post miscarriage patient.
It could be tage performed for any reason.
They typically present with bleeding,
many times massive bleeding that may require transfusion.
And it's important to identify these patients
as you may want to consider treating
with embolization rather than abilitation and tage
or do the AVMs look like.
Here's a patient,
retroverted uterus,
transvaginal scanning sagittal view.
We see all these little cystic to tubular spaces
in the myometrium.
And then with color and spectral imaging,
we show this focal increased vascularity
with low resistance arterial flow that's typical
of a uterine a VM.
It's important to realize
that these uterine AVMs can be overdiagnosed,
particularly in a postpartum or post miscarriage patient.
Focal low resistance flow in the myometrium can be seen
after term delivery and after spontaneous abortion.
And it's thought to be due
to what's been termed in some studies sub evolution
of the placental bed.
Its incidence has been reported
to be the highest in the second postpartum week.
Now you can also see this focal low resistance flow,
with retained products of conception
or even with a molar pregnancy.
What we're recognizing is many of the so-called AVMs,
what sometimes have been diagnosed as AVMs,
in the postpartum period actually resolves spontaneously.
So it's important not to over-diagnose these, not
to rush off to treat them with embolization.
So when you're considering this diagnosis of a uterine a VM,
if the patient was recently pregnant
and stable,
don't rush off to treatment right away.
You may want to check the serum HCG, look for other evidence
of gestational trophoblastic disease,
and
consider a follow-up ultrasound in these patients
because many of these will resolve.

Ovarian Vein Thrombosis

And lastly, ovarian vein thrombosis.
CT
or MR is certainly gonna be more reliable in most
patients for this diagnosis.
Here's the CT scan, the thrombo right ovarian vein.
So we are gonna depend more on CTMR
to make this diagnosis in many patients.
But the point I'd like to make is that when
you do pelvic ultrasound in the postpartum patient,
and that often is the first imaging test, whether it's
for bleeding or pain,
don't just look in the pelvis if you're even remotely
considering this possibility
of ovarian vein thrombosis look a little higher up out
of the pelvis than you probably typically would
for many patients during the pelvic ultrasound.
Look up where the right ovarian vein would
typically enter the IVC.
Here's a transverse view more
through the mid abdomen aorta IVC.
Here's this thrombo ovarian vein.
We turn longitudinally on the inferior vena caven.
You can actually see a little bit of the thrombus
as it protrudes into the inferior vena cava.
So look a little higher up.
You're more likely in my experience
to make the diagnosis if you look here than just in the
pelvis,
in these patients.

Summary

So to summarize,
retained products of conception
or placenta, hyper co mass seems to be the best feature.
However, it's probably less reliable in the postpartum
patient in the first approximate two weeks.
If you don't have a mass and you only have endometrial
thickness to go by to predict retain products.
I think based on what's out there at the moment,
somewhere eight to ten's probably the best cutoff I
currently use 10.
However, it, we really don't know the most reliable
thickness to discriminate patients
who can be treated,
conservatively.
But if it's less than approximately 10 clinically
significant retained products of conception seems unlikely.
Doppler ultrasound can certainly sway you seeing flow favors
retained products, lack of flow favors, clot.
And so they can certainly push you one way or the other.
But it doesn't seem that either is totally
reliable at this point for retained placenta.
Remember that hyper coic material complex fluid,
can
be difficult.
Try to distinguish it from a true mass,
which would be more vocally hyper coic.
But complex fluid
or hyper coic hypo coic material is probably not predictive
of retained placenta.
If you see hyper coic mass, that seems
to be more predictive.
If you only see echogenic foci in the endometrium would try
to determine whether it's in a mass.
In that case, it'd be more concerned about retained products
or whether it's just scattered diffuse echogenic foci
without a distinct mass.
In that case, I think it's more
or less likely to be retained products.
Remember that there are other serious causes
of vaginal bleeding besides retained products.
They're rare, but you want
to at least keep them in the back of your mind.
That is av malformation, postpartum placenta accreta
and placental site trophoblastic tumor.
And still be very careful about diagnosing
AVMs in the postpartum or post miscarriage period.
Even though sub evolution has been described more in the
postpartum patient in the first two weeks,
I have occasionally seen it in the first trimester pregnancy
losses where there's abundant low resistance arterial flow
focally in the myometrium.
And you follow those patients and it resolves.
So be very careful about diagnosing a VM in the postpartum
or post miscarriage patients.
It's often sub evolution of the placental bed.
And if you can, if those patients are stable
enough, just follow them.
And many times those doppler findings will resolve.
Remember the post cyan section,
patient know the normal appearance, beware
of the appearance in the un,
or less common cases of the classical
or vertical incision in the uterus.
Hematomas in these patients is the most common
in the bladder flap area.
That is the anterior load uterine segment.
But also remember subfascial hematomas.