The Fetal Genitourinary System - HD

Introduction

Hi, my name is Tom Winter.
I'm from the University of Utah,
and we'll be talking about sonography
of the fetal genital urinary system.
And these are just some views from Utah.
This is Horseshoe Bend
and we're gonna divide the talk up into
four major categories.
We're gonna talk about goals, normal anatomy.
Most of the talk will be focused on specific anomalies.
And then we'll finish up with a brief discussion
of in utero therapy.
I've got a couple disclosures here, none
of which are relevant to this talk.

Goals

So what are the goals by AIUM criteria, we're obligated
to document the bladder, the kidneys in the
amniotic fluid volume.
And if we see something wrong,
there are five questions we want to answer.
So we're gonna go through each
of the five bullet points on this slide in
a little bit more detail.

Question 1: Oligo/Hydramnios Present?

Question number one is oligo hydros present.
Now I have a very bad memory, so I love mnemonics
and this was taught to me by Dr.
Delores Pretorius.
But think of fluid dripping out of the amniotic cav cavity,
D-R-I-P-S.
So the six things we want to think of are D for demise.
R should really stand for genital urinary,
but we'll use it here for renal.
There are two eyes, growth restriction
and tocolytic like endeth asin.
The latter can decrease the amniotic fluid over a
very short period of time.
Obviously post maturity and spontaneous
or preterm rupture of membranes are causes
for a posity of fluid.
But again, this talk is gonna focus on the
genital urinary system.

Question 2: Is the Urinary Tract Dilated?

Is the urinary tract dilated? If so, where is it?
Proximal, like a UPJ or distal like A UVJ.
Has it spontaneously decompressed with ascites or a oma?
Is there a rare extrinsic cause like a hydrometric copost
pushing on the bladder?
And remember that just as in pediatric
and adult populations,
dilatation does not always signify obstruction.
You can have reflux
and rare congenital anomalies
that give dilatation without obstruction.
So here's an example of a ureteral vesicle junction.
You can see the dilated ureter coming all the
way down to the pelvis.

Question 3: What Do the Kidneys Look Like?

What do the kidneys look like in terms of size,
shape, and echogenicity?
A really nice rule when you're in the room scanning the
patient is that the age in weeks plus five is the length.
So you can see at 20 weeks, 20 plus five is 25,
the actual number's six at 30 weeks.
30 plus five is 35, the actual number is 38.
And notice that a standard deviation is a little bit less
than half a centimeter.
Are there kidney cysts present.
This could be an obstructive neuropathy
as the number one cause a whole bunch of syndromes.
The rare isolated cyst in your utero.
And then there are some pitfalls.
You don't want to confuse dilated CAEs with kidney cysts,
but real time you can scan back and forth
and these col connect up
and it's obvious that this is
dilated CAEs rather than cysts.
And then probably one of the most important points is
that if you see a fetal abnormality
of any type, keep looking.
It's well known from the work by kiros Nicolaes
that if you have two anomalies on in utero ultrasound you
have three or four at autopsy.
If you have three on ultrasound, you have five
or so, I'm making up the numbers, but you get the point.
So have a structured search pattern and don't get burnt,
but just keep looking at everything.
And so here's an example
of bilateral cystic dysplastic kidneys.
But you don't wanna stop there
because this kid had anencephaly
and this was a form FRS of mecal Gruber syndrome,
which has a 25% recurrence risk
because it's autosomal recessive,
whereas just bilateral multicystic dysplastic kidneys would
be much more down in the two to 5% recurrence risk.

Brief Introduction to Physics

When I talk about physics,
the residents run screaming from the room.
But we'll have a brief introduction to physics.
This is just kind of cool if you like history,
but these were the first acoustic amplifiers.
This is World War I and they were trying to detect planes.
This was pre radar, so there was nothing electronic in any
of these setups here.
But you can see just simple acoustic amplification
with a human in the center of it.
And these just get more
and more elaborate as you go through the examples.
I think my favorite one is coming up here.
This looks like something from Alice in Wonderland here.
But again, no electronics.
These are just acoustic amplification of noise.
So that's the only physics we're gonna
talk about in this lecture.

Normal Anatomy

Amniotic Fluid Volume

Okay, normal anatomy.
So let's start with amniotic fluid volume.
In the 1950s when radiation was our friend, they used
to inject radioactive isotopes into the amniotic cavity
to quantify the volume of amniotic fluid.
Can you imagine trying to get that by an IRB today?
But now we do dye dilution
and roughly a third trimester fluid volumes a
little bit less than a liter.
Remember that before 16 weeks the fluid volume may be normal
without renal function
because the fluid will kinda leak out through the skin
because the skin hasn't keratinized and cornified.
Conversely, if you have a normal fluid volume in the second
half of gestation,
you've got at least one functioning kidney.
It may be a pelvic kidney or cross FU dystopia,
but there is a kidney in there.
A normal amniotic fluid volume generally signifies a pretty
good prognosis and the setting
of a genital urinary abnormality.
And although most GU abnormalities cause a posity of fluid,
there's a couple that can cause a paradoxical polyhis,
a unilateral UPJ multicystic,
dysplastic kidney aplastic nephroma,
the mega cys, et cetera there.
So here's just three different PA uh papers
pulled together by Dr.
McGahn who's kind of the guru
of amniotic fluid volume on ultrasound.
But you can see that again in the third trimester it peaks
around 800 ccs.
Probably the best way to assess amniotic fluid is just
to look at it and there's obvious lack of fluid in crowding
with oligo and the kid is swimming with poly there.
And there's some literature showing
that an experienced operator just looking at it is as good
or better than the semi-quantitative methods.
So here's an example of a pseudo emale.
This is not an emale, it's just the belly being squished
by a posity of fluid.
Now there are two semi-quantitative methods.
One is the single deepest pocket or maximum vertical pocket
or maximum deep deepest pocket has a couple different names.
And depending where you want to be on the ROC curve
and which author you choose,
there's different literature out there,
but I think most people say single deepest pocket has
to be over two and under eight.
And just like amniotic fluid volume, you measure down
to the cord or the arm, you don't go all the way through it.
So here's an example of a single deepest pocket
of four centimeters on this nice extended field
of view imaging of a complete posterior placenta previa.
Amniotic fluid index is the other one.
You just take all four quadrants, you know, paying attention
to measurement technique,
it's gotta be more than a centimeter wide.
And you measure down to quarter part, you add 'em up,
it's always between normal's, always between 10 and 20.
Here's an example of four pockets there.
You go to these charts by gestational age
and put it at a percentile right there.
There's all sorts of uh, data out there.
But realize that a couple things about amniotic fluid index,
even though between five
and eight, maybe less than the five percentile for age,
there are two ACOG practice bulletins as saying
that an a F five greater than five is normal fluid volume.
You shouldn't alter management.
And then like everything in medicine
and life, there are variables here.
If you put mom in left lateral decubitus position,
you'll get a lot more fluid.
If you have mom go down to Starbucks
and chug a bunch of fluid baby's amniotic fluid volume can
increase by about a third right there.
Now we have two semi-quantitative methods, the SDP
and the A FI, and I won't bore you with all the literature,
but essentially everybody is coming down on the side
of the maximum vertical pocket now saying that it's just
as sensitive as a FI at picking up a positive fluid
and it has many fewer false positives there.
So we don't torture patients and over manage them.
So here again is just talking about
how the SDP is preferred.
It's easier to do and it has less false positives,
especially in twins.
And again, remember the width of the pocket has
to be greater than a centimeter
and you've got to measure it properly.

Kidneys

Moving on to kidneys, they're seeing, you know,
around 14 weeks, you start
to see the cortical medullary differentiation
around 16 or 18 weeks.
We already talked about the renal size.
Don't confuse the hypo coic medullary pyramids
with hydronephrosis.
That's a mistake I made many times early in my career.
But the renal cortex is very echogenic and fetuses
and peds up to six months.
So these are the normal pyramids, not to be confused
with hydro, we do a fair amount of fetal MR in our practice.
Here's a coronal view showing the kidneys a sagittal view,
showing the kidneys and axial view, showing the kidneys.
You can use doppler to find the renal arteries.
Works great in theory and in books.
It's not quite so, uh, robust in practice,
but it's a nice thing to look for.
But just be aware that you can be confused
by splenic arteries, by lumbar arteries, et cetera.
So here's a fetus around 20 weeks.
20 plus five is 25,
and instead this is almost double the length,
which is gonna be, you know, uh, cube, the volume.
So this is a huge kidney on the left.
Similarly, a huge kidney on the right.
Then we have a big tongue
and since we're in medicine, we can't say big tongue,
we say macroglossia.
So this is a pretty classic appearance for beck
with wheatman syndrome.
This has management implications.
So again, renal size is length,
is age in weeks plus five
Usually see it after 13 weeks.
Here's little boy peeing, a little boy peeing right there.
The British only they would have the, uh, tenacity
to do a study like this,
but they measured the length, the width,
and the height of the bladder every two minutes for 24 hours
and that's where they get numbers.
Like it fills an empties every 30 minutes per hour
and produces 30 ccs per term.
And since I just showed a little boy,
here's a little girl taking a leak in the
amniotic fluid right there.
So doppler is really nice for things besides blood flow.
Think of looking for coen atresia when you're breathing.
Dopplers really nice for that
three vessel cord in practice, if we see two arteries
around the urinary bladder, here's two different cases.
We infer that this is a three vessel cord. It's a good rule.
But we published a paper years ago going through all
of our two vessel cords as you see here,
and found a very small percentage of them
actually had two arteries around the bladder
and this kid actually had a meningocele.
Now who knows the strength of this association.
So in default we, um, use this,
but just remember that if you can try
to get it in the amniotic fluid volume
and that may be a little bit more robust
gender determination, be very, very careful here.
It's medically necessary and useful in cases like twins
because if you can prove opposite genders,
you've proven zygosity
and put them in the lowest risk twin gestation there,
it's useful if you're doing amniocentesis on multiple
gestations and a couple other things.
But one of the worst experiences I had in my career was
sitting in the reading room
and hearing an assault going on in the scan room
and I ran in there and the husband was physically beating
his wife because the sonographer had told him
that it was a baby girl.
So my rule is if I get weird vibes from the parents,
I just kinda lie and say that I um,
I can't see the baby's gender, uh,
because the baby's spine up
or the legs are together right there
and always let the parents know
that we're over 99% accurate now,
but we're still not a hundred percent
so we can get burnt as well.
So we just talked about some of that stuff there and,
but most of the time we are very good.
Here's obviously boys right here, three different examples
I put this in to remind us that in the absence
of any other findings,
hydros EALs in the third trimester are a normal variant.
Remember that the processes vais patent
and the testicles head down
through the processes into the scrotum there
and you get a little bit of fluid.
And for female fetuses you see the labia.
Here's a newer study, here's an older one right there.
But one of the causes of falsely assigning gender
is the labia respond to maternal estrogen stimulation
and the hypertrophy.
Then the umbilical cord flips between the legs
and it gets confused for a penis
and you'll call a girl fetus a boy

Specific Anomalies

getting onto specific anomalies.
Pretty much anything you've seen
or studied in the pediatric
or adult population may be seen here.
So here's a pet study from last summer showing increased
uptake at the dome of the bladder there.
This was a iCal carcinoma
and here we are in utero showing the, uh,
relevant embryology look at the Alan Tous
and the um, UCal connection there
at the dome of the bladder.
So embryology is real stuff
and has correlates with postnatal pathology.
Briefly, we'll talk about the adrenals.
This could be a whole nother lecture in itself.
You know, I've seen five cases
of neuroblastoma in utero.
You can have hemorrhage or something like that,
but normal adrenals are quite a bit bigger in utero than
they are postnatally.
So here is a normal adrenal
prenatally in two different patients
and this is a neuroblastoma hyper coic wrapped
around the aorta.
And this was called a meso blast.
Nephroma outside,
but notice that it's wrapping around the aorta there.
It's in the retroperitoneum.
This is not centered in the kidney.
Here's that fetus on an mr.
You can see it's sitting above the kidney right there.
So this is neuroblastoma and utero
and here's one of two cases I've seen
where the neuroblastoma actually gave liver mets
and placental mets
and both kids did great postnatally with chemotherapy.
So this is equivalent to the stage four s
that despite widely metastatic disease responds
well to modern therapy.
Here's one that was called a neuroblastoma
outside big echogenic mass apparently in the abdomen,
but remember that the posterior costophrenic sulcus
comes down low.
So here's the extra low bar sequestration,
displacing the lung and the heart.
So remember that thoracic
abnormalities can mimic abdo abdominal pathology if
you don't scan yourself.
And here's another C camm.
You can see that if we cut posteriorly we'll get something
that might be confused with a um, abdominal process.

Kidneys

Kidneys. Here's a cute example of a horseshoe kidney.
You can see just like this here.
So it looks just like it does in pediatric
and adult population.
Hydronephrosis is a big thing.
People have been talking about this for years.
Typically male fetuses,
there's been a bazillion measurements postulated over the
age in reality, all you need to do is the frontal view
of the, uh, AP diameter of the renal pelvis
and assess for cal c dilatation.
Those are the two things on the most recent version
of our assessments.
This was until, uh, earlier this year.
This was the standard four millimeters before 33 weeks
and seven millimeters after 33 weeks.
We're now using four millimeters before 28 weeks
and seven after 28.
It's kind of complex.
Take a look at the uh, paper done by nim.
It was a NIH consensus panel there.
You probably have to post it in your reading room
because it, it's divided into antenatal one, two,
and three risk factors.
Depends on the AP diameter of the pelvis,
the intrarenal collecting system dilatation.
And then there's specific recommendations about follow
up that follow that.
Couple points though.
Number one, this is kind of pseudoscience A nice paper
by Wayne UTI showed that if you looked long enough, um,
using a five millimeter threshold, two thirds
to three quarters of the patients would be both normal
and abnormal over two hours.
Number one. Uh, number two, if mom goes to Starbucks
and drinks, she may have um, fetal ectasis there.
And then number three, remember Roy Philly's.
Superb editorial, obstetric sonography.
The best way to terrify a pregnant woman if you, um,
in general, if the AP diameter,
the renal pelvis is under 10 millimeters
and there's not any associated findings,
it's almost always a normal variant there.
So you don't want to terrify the parents.
So what to do, this was the
pen ultimate recommendation here using the four and seven.
Then there's another one after this.
Again, a lot of these are not data driven,
driven their expert opinion,
but if you wanna stay current, take a look at the paper
by NIM that came out um, a bit after this one.
So UPJ obstructions one of the most common causes
of a utero obstruction.
This is one of these that can give you a
paradoxical polyhis.
And the prognosis depends on the opposite kidney
amniotic fluid volume and assuming it's isolated.
So here's a bad UPJ, little bit of overwork
of the other kidney, but it's fine.
This kid did great. Here again is A UPJ,
but the other kidney was happy.
The amniotic fluid is happy. This kid did great.
Here's a big bad UPJ.
Remember that we said 10 millimeters even though we start
calling it at four, it's not till it gets to 10
that it tends to have a correlation with postnatal outcomes.
So here's a big one, a little bit of ectasis on this side.
Here's the bladder, but big UPJ.
So you can see these severe ones all look the same
but there was normal amniotic fluid volume there
and this kid did fine.
There's a weak association of ectasis and down syndrome.
This is one of the first, um,
soft markers that was described.
Fortunately this is all going away with the advent
of the non-invasive pregnancy testing.
But if you don't have access to the NIPT or NIBD
or cell-free fetal DNA keeps changing names, you may want
to um, realize that this is a soft marker
and in isolation it has a very low predictive value.
But if you have a bunch of other things,
you're gonna worry about down syndrome.
So here's an example of a fetus with down syndrome
with mild bilateral pi, pelvic ectasis who also had a bunch
of other soft markers.
Okay, renal agenesis, if it's bilateral, it's lethal.
If it's unilateral, um,
you do just fine assuming the other kidney's.
Okay? Remember
that if it's unilateral you're gonna have an association
with uh, uterine
problems if you're a gal and seminal vesical
and stuff, if you're a boy right there.
But if it's bilateral, it's a tough diagnosis to make
because you have anhydrous.
And so, um,
in the old days we would put amniotic fluid volume in
by just putting in isot tonic fluid with a reverse amnio.
And look, we almost never do this now
because anhydrase at 18 weeks
has a horrendous prognosis regardless of the cause.
And remember, if you feel see the bladder filling
and emptying, you have a kidney in there.
You may not be able to see it but it's present.
So remember that we said
that in utero the adrenal is significantly larger
proportionally wise compared
to the kidney than it is postnatally.
So you don't want to confuse this with the kidney.
I've done that several times.
Here's a fetal autopsy MRI in a different case showing
how big the normal adrenal is.
What are clues?
You get the lying down adrenal sign
or the pancake adrenal sign.
Remember that this is not specific for renal agenesis.
It could be cross fused opia or a pelvic kidney,
but it just means that you don't have a kidney in
orthotopic location.
As we talked about, you can also use doppler
to look at the renal arteries but be careful.
But here's a case of a normal kidney on the right side
and that lying down adrenal sign on the left side.
But we have normal stomach, normal amniotic fluid volume.
This kid's doing fine again, normal kidney on the right,
lying down adrenal on the left.
Normal amniotic fluid volume.
Here is a uh, cross fused utopia
where you can see an extra renal artery going
to the lower pole there.
Here's in utero
and this is where MR is nice if you don't have the amniotic
fluid volume that really hurts you in ultrasound
but it doesn't hurt you in mr.
But here's a case of unilateral agenesis
and here's some doppler just showing normal right kidney
lying down or pancake adrenal sign on the left side.
Normal right renal artery, no left renal artery
And that's isolated.
But look at this case, compensatory hypertrophy
of the right kidney and utero, no kidney on the left side.
And this was trisomy 18.
So obviously prognosis
and management are 180 degrees different if you have renal
agenesis as an normal variant versus associated
with Edward syndrome.
So don't get fooled by the adrenals like I did in this case.
Early on in my career I said there's no fluid
but look, there's a kidney there and I took pictures of it.
So went through a long differential
and here's the other kidney that I said,
oh there's the kidney there.
But when that kid, when an autopsy was done,
those were hypertrophy adrenals.
And you can see in this case different patient,
absolutely no evidence for a renal artery on either side.
And here's just some necropsy examples showing bilateral
renal agenesis to different patients there.
And there's nothing in the retroperitoneum
and we'll compare that to the polycystic kidney
disease coming up.
Cross fused utopia.
Again making the point that anything you can see in utero,
you can see postnatally.
So here's just a big lumpy bumpy kidney, no kidney here.
This is not a genesis, it's cross fused utopia,
big lumpy, bumpy kidney there.
If you don't see anything in the renal fossa,
ortho topically go down into the pelvis.
Here's the bladder, here's the pelvic
kidney, here's the bladder.
Here's another patient with a pelvic kidney.
And there was a little bit
of a renal artery coming out feeding it there.
Duplex anomalies. This is about the only genital urinary
abnormality that preferentially hits females.
Typically they're rera seals.
Everybody that's passed boards has memorized
the Wyer Meyer rule.
So the upper pole moty inserts inferior in medial
and obstructs and the lower pole refluxes.
So here you can see the upper pole obstructing
the lower pole refluxing and there's a gigantic utra seal.
Here's another one, gigantic urease seal
and then upper pole obstructing lower pole refluxing
ureter seal in the pelvis.
So these look just like they do when you're picking them up
in children or adults.
Upper pole obstructing lower pole refluxing.
Here's the right kidney, hydro nephrotic,
big dilated ureter coming down to the bladder.
Here's the ureter seal.
Again, see
how these all look the same Upper pole obstructing,
dilated ureter, ureteral ureteral.
15% of the time they're bilateral.
This is from Dave's book here.
Here's a really cool one from Dr. Savita and um, Chile.
And this just turned out to be a bilateral ureteral seal.
You can see upper pole obstructing lower pole refluxing,
but they just look kind of funny in the bladder there.
Cystic renal dis uh, disease.
The two things we're gonna
commonly see are multicystic dysplastic in an obstructive
neuropathy in adults all the time.
We see isolated renal cysts.
This is the only one I've ever seen in utero.
They're incredibly rare.
We were worried that this was a cystic neuroblastoma,
but it turned out to be an isolated cyst.
Multicystic dysplastic kidney, not uncommon.
Most of the time it's unilateral
almost pathognomonic experience.
Appearance rarely associated with other things,
but 40% of them have contralateral renal abnormalities.
And again, there's some debate about whether
to offer amniocentesis or not for genetic testing.
I don't think that's settled.
Our MFM docs generally do
so embryology, this is just a very severe form
of A UPJ obstruction.
So remember that the meric plAsa has
to meet the ureteric bud in utero.
If they don't, you get the most severe form of A UPJ,
which is an MCDK.
Here's what they look at at path.
Here's an autopsy we did with MRI showing bilateral MCDK,
sonographic.
Really the only differential would be a UPJ.
But in A UPJ, these cysts communicate here.
They don't communicate at all.
Here's another one, just a classic,
classic appearance for MCDK.
There's really nothing else
that it's gonna be nice bladder there.
The kid's gonna do fine because the opposite kidney is fine.
Here's an older one MCDK on one side middle
but pile on the right side because it's working harder.
But notice that we have a fetal bladder
and the kids waving saying Hi mom, I'm gonna be okay
because I've got a good volume of amniotic fluid volume
and we can do MR again.
Here's a unilateral MCDK.
But the key thing to remember is that up to a 40% incidence
of contralateral abnormalities, about half the time, 20%
of the 40% it's MCDK on the other side.
So they're functionally aric and this is lethal.
And here's bilateral MCDK at autopsy
MCDK here, MCDK here.
This is not the bladder. This is a gigantic
cyst on this kidney.
Notice that there's no amniotic fluid volume around
About a quarter of the time.
10% of the 40% you have MCDK on one side,
agenesis on the other.
Your images are awful
because you have no amniotic fluid volume right there
in about a quarter of the time.
The other 10 outta 40%,
you have hydro on the other side typically from A UPJ
and your prognosis depends on here's your MCDK,
here's your UPJ, how severe is this UPJ?
If it's mild and fluid is getting
to the amniotic cavity, great.
If it's severe and you don't have enough fluid, that's bad.
Here's one where MCDK on the left, um,
and the UPJ on the other side, we actually attempted
to insert a drainage catheter into this,
but I think it was too little too late and it didn't work.
Then the other common type of cystic change
that you'll see in the kidneys is a sequelae of obstruction.
Typically posterior urethral valves.
There's a couple other rare things that'll cause it.
So this is what it looks like at autopsy,
just multiple cysts and calcifications.
It's important to notice, mention these cysts
because if you see cystic change in a kidney as a result
of obstruction, um, that means the kidney is not working.
It's histologically abnormal
and no amount of heroic therapy within utero
rocket catheters is gonna work.
Again, if you look to just the top here, you'd say, oh,
that's bilateral MCDK, but we've got a bladder.
This is posterior urethral valves.
And given that we have cystic change here,
even if you drain the bladder, these kidneys aren't working,
it's too little too late.
And here's another case, here's another one.
These are all posterior urethral valves.
But if you had urethral atresia,
oral agenesis, it could give this.
Here's a fascinating one from last summer
just showing the change.
We had A UPJ
and we just thought, okay, it's a UPJ, let's follow it up.
And I think this was six weeks later.
And look at how we've got cystic uh,
change in the kidneys six weeks after A UPJ.
Then there's a bunch of rare things that can cause cysts.
Autosomal recessive, polycystic kidney disease,
also known as infantile.
Remember that there's an association
with hepatic involvement here.
These children do not live
because of pulmonary hypoplasia,
but despite the name of polycystic kidney disease, remember
that we don't see the cysts at ultrasound, you know,
a hundred percent of the time there.
So you're seeing dilated tubules. So here's an example.
Look at the size of these kidneys.
Different case notice that we do not have dilated um,
cysts that we can see here.
You have to go down to a microscope to see them.
Here's a bunch of different cases. Big echogenic kidneys.
Poor differentiation there.
Five centimeter long kidneys in 20 week kids. Abnormal.
Here's five to six centimeter long kidneys and 18 week kid.
Big echogenic kidneys without cysts.
Again, genic kidneys without cysts,
but no fluid genic, big kidneys without cysts.
No fluid in the most spectacular case I've seen.
This is an 11.6 centimeter kidney.
Most of us in this room have kidneys of this length
and add autopsy.
Here's the kidney again. Notice that you don't see cysts.
Here's the heart, here's the lungs, here's the liver.
And this is an adult-sized kidney in a preterm fetus there.
Here we have an autopsy showing it.
Here's a classic necropsy showing
how gigantic these kidneys are displacing the uh,
liver out of the abdomen.
Autosomal dominant. Let's skip this. It's really rare.
Generally just take a look at the mom
and you know that she has it.
There tends to be less severe than the autosomal recessive.
I got these from Dolores's paper
because I don't know that I've ever seen a case of it
syndromes associated with renal cysts.
The typical trisomy we already saw Mekel gruber
and the list goes on and on and on.
But remember associations, this was a June syndrome here,
but more importantly, look at this one, bilateral
cystic dysplastic kidneys.
Here we are at autopsy.
And then notice the posterior occipital and kee.
This has a 25% recurrence risk.
And you can see the classic at autopsy, postnatal
polydactyly post axial meaning
that it's coming off the pinky or the little toe side there.
So the triad of mecal gruber is the cystic dysplastic
kidneys, the post axial polydactyly, the encephalocele.
And obviously you don't get good pictures
because there's no fluid.
And we've seen a couple cases, mom's doing crack
and we see cysts in their kidneys.
Is this an ischemic phenomenon? Who knows?
Could be just an association finishing up
kidneys, meso blasts.
Nephroma is pretty much the only solid MAs she'll see in
utero other than a cross fu dystopia.
It's got a bunch of different names there.
Point to make, there's never been a renal cell in utero.
There's only been two case reports of Wilms in utero
that I'm aware of.
So these are benign tumors that are associated with poly.
They generally take them out though at some point.
So huge kidney right here.
Huge kidney mass right here associated
with poly big kidney mass.
Here we are at autopsy or not at autopsy surgery.
These things can be hypervascular prenatally.
Look at all the blood flow going into them postnatally.
So you can have a high output cardiac failure
with meso blast nephroma just like you can with
sacral al Teratoma or um, Vanna Galen aneurysm.

Ureter

Moving into the ureter is a big ureter.
We're in medicine so we have to say mega ureter.
This could be obstruction from UVJ or ureteral.
Could be reflux, could be neither.
Lots of times other GU anomalies are present.
Only differential is to distinguish ureter from bowel.
But the ureter generally touches the spine.
Starts from the renal pelvis and extends behind the bladder.
So big dilated ureter coming down.
Hydronephrosis, big dilated ureter coming down.
Hydro necrosis, big dilated ureter coming down.
They all look the same.
Here's a cine clip showing hydro necrosis
and a big dilated ureter coming down.
This is a UVJ right here.

Bladder

Big bladder mega sti.
Let's divide this into two categories
In the first trimester, um, again, kiros Nicola like he has
for so many things has led the way here.
So they define it as a bladder
of over seven millimeters at the time of the 10
to 14 week scan.
Male predominance.
And it does have an association
with renal anomalies like you'd notice.
But the interesting thing is it's got about a 25%
association with aneuploidy
or funny chromosomes right there.
It's typically, um, patal syndrome.
Then Edwards not down syndrome right there.
So if you see this, obviously you're gonna follow it up
because you're worried about
posterior eural valves or whatever.
But even if the kidneys are normal, you're at increased risk
for aneuploidy and you're gonna want
to look at the lucency then.
And again, as we're moving to routine use
of the cell-free fetal DNA, this will become less
and less of an issue.
But moving into later in pregnancy,
it's typically posterior urethral valves.
This is one of the times when it's
important to determine gender.
Again, these are associated with uh,
other things in the GU system.
Other things structurally in chromosomal there is a
differential of a urethral stricture, persistent cloaca,
megas, MicroCon, et cetera.
But it's almost always um, poster urethral valves.
So what are the ultrasound findings? You get big kidneys.
Remember we said, you know, five
four millimeters is abnormal.
Well this is like 20 here, so this is not an issue.
Here's the keyhole.
Now up to half of these kids have a normal amniotic fluid
volume, meaning that the fluid is leaking out
through the valve is not a hundred percent obstruction
and the lungs develop and they do okay.
And up to half of these kids
may have normal kidneys right there
because you have a one-way valve
as the ureter plugs into the bladder.
And if that one-way valve stays intact,
then you get a big bladder and urethra.
But nothing in the kidneys there.
But at boards in Louisville we're gonna showcases like this.
So again here you can see just big dilated
kidneys bilaterally.
Big ureter right here.
If you see cortical cysts like we saw earlier in the
lecture, that means there's no point in doing heroic
measures and draining the bladder.
Here's the dilated proximal urethra, the keyhole
spontaneous decompression, urine ascites.
Here's a kid we saw. This is mom's bladder.
There's no fluid around the baby.
Here's the placenta, here's the bladder.
Comes back for follow up and the bladder's popped.
Here's urine ascites outlining bowel loops.
Here's another one you can see on July 22nd,
we have the keyhole appearance to the bladder there.
Huge bladder echogenic kidneys, no amniotic fluid volume.
And then we come back four days later
and notice that the bladder has ruptured.
We have URA ascites outlining loops of bowel right there.
And again, echogenic kidneys.
And here are two autopsies of fetuses
with posterior urethral valves just showing
how huge the abdomen can be.
There is a differential.
You can have, um, eagle Barrett syndrome
or uh, what is it?
The abdominal wall laxity, cryp orchids
and genital urinary abnormalities.
Prune belly syndrome.
That's the word I was looking for there.
And sometimes it's tough to tell the distinction there,
so you want to be aware of it.
But typically the prune belly has a normal
amniotic fluid volume.
So the prognosis is gonna be much, much better.

Other Findings

IU rle remnants.
Here's the Alan Toic duct coming up there
and in a different fetus you can see the bladder.
And then here's the UCal connection coming up.
And then I put this in just for people getting ready
for the registrar exams.
For the longest time there was only a couple cases this
floating around provided by Harris Finberg
and you'd see them in all the textbooks.
But this is big bladder, tiny colon intestine,
not moving syndrome there.
It mimics posterior urethral valve.
And then you have a big bladder with hydronephrosis,
but it's typically females with poly hydrous there.
And so again, this is from Harris,
a big bladder hydro necrosis,
but uh, micro colon,
they've given the kitab barium meal.
It hadn't moved over two days.
Intestinal hypo peristalsis mesti finally saw my
own case of it there.
Female fetus, huge bladder,
but polyhis fetal hydros seals, as we mentioned
before in isolation, these are normal.
They document the testicles. Ni uh, nicely there.
Hypos staus, um, associated with a bent cordy there.
Make the diagnosis with caution
because most of the time it's just a funny position
and the parents really freak out.
Ambiguous genitalia again make the diagnosis
with caution because the parents oftentimes freak
out right here.
This was a case of trisomy 18.
So you really want to get a big subspecialty workup then.
Fetal ovarian cysts are very common.
They're seen in autopsy studies at about
30% of the time.
It's in response to maternal estrogens.
There most go away within a few months after birth.
But um, so here you can see female fetus,
too many cystic structures in the belly.
Bladder cyst stomach. This is an mr on a different patient.
There, there's a couple, uh,
maybe really out there papers saying
that if you see a large one, you should go in
and aspirate it in utero to prevent torsion.
Most people think that's crazy.
But here is one case of this
that we saw here we are prenatally and postnatally.
The kid comes in, here's a debris level.
There's no flow in this.
So this was the rare case of an ovarian cyst leading
to torsion finally in utero therapy.

In Utero Therapy

The idea is if you have
posterior urethral valves early on,
if you can stick a double pigtail catheter,
one end in the bladder, one end in the amniotic space
and decompress the bladder into the amniotic space,
you may protect the kidneys there.
So there's two issues with this. Number one is technical.
I've got videos of kids grabbing these
things and pulling them out.
So we try to come in from the back,
put little barbs on them like fish hooks.
So they won't come out. They often clog
or they get sucked into the kid.
But even if you had a perfect system, which we don't, uh,
the issue is are you shutting the barn
door after the horse is left?
So before we do something like this, we will, you know,
make sure there's no cortical cysts,
then we'll do a puncture, take out the urine in the bladder,
throw it away, do another puncture shortly afterwards
to get fresh urine, send it to the lab, have them check it
to make sure the kidneys are concentrating.
And then if the kidneys are still working,
then we'll go ahead and do this.
A lot of debate about efficacy.
But you know, we'll do a couple a year of these.
So here's an example. Classic posterior urethral valves.
We did all that. Showed that the kidneys were working
and here you can see the needle coming in
and here we're coming in
and deploying the rocket uh, catheter right there.
And this one went pretty well.
Then the other thing is if you have anhydrase
from whatever cause should we just install
amniotic fluid volume?
And essentially the answer is no.
But just like everything in medicine, there is a,
uh, exception to it.
Last summer there was a case where they did this every week
or two, um, for, you know, months and months and months.
And the kid did kind of okay,
but then the editors of the green journal said,
uh, you know, be careful.
This is the exception, not the rule right there.

Conclusion

So our goals are to document the bladder,
the kidneys in the amniotic fluid volume.
We wanna look at normal anatomy, we wanna look
for specific anomalies.
Anything that we can see postnatally
and we talked about in utero therapy there.
So document bladder, kidneys, and amniotic fluid volume.
If you see something funky, answer these five questions.
So I'd like to thank Dave and Ann
and Harris for images there, Dawn for the early radar images
and Sierra Club for the old desktop calendars.
Thank you very much.