Top 10 Anomalies - Don’t miss this show! - HD

Introduction

My name is Anne Kennedy.

I'm a professor of radiology at the University of Utah
and an adjunct professor of obstetrics and gynecology.

And today I'm going to talk about things
that I think are very important to be aware of during second
and third trimester sonography.

Ideally, these are things
that should not be missed in any scan.

When I was first approached by the AIUM
to put together a series of don't miss diagnoses,
in the second and third trimester on fetal ultrasound,
the title given to me was the Top 10 Anomalies.
Don't miss this show.

As I grew up in London in the 1960s, it seemed obvious
that I should parallel top of the Pops,
which was a favorite show on a Thursday evening
where we went over on tv, all
of the top 10 hip parade songs.

So each anomaly has a musical introduction
and we're going to start at the more rare things
and make our way to the stuff
that I think is the most important.

Cloacal Malformation

Starting with fire down below
and rolling in the deep, you have
to think about things down there.

Moms love to know the gender.

If you look up a gender reveal party on Google,
you get 32 million results in no time at all.

And as any of you who are sonographers know, everyone wants
to know is it a boy or a girl.

So while you are down there checking the genitalia,
there are other things that you can look at
and I'm going to show you some anomalies that are rare
but very important to recognize.

So this is an axial image
and this is a coronal image through the pelvis.

And you can see we have these two fluid filled structures
that have an air fluid level.

This is the umbilical cord.

And so this is an umbilical artery.

This is coronal, this is the fetus head end,
this is the bottom end.

And again, two tub structures with a fluid level.

And if you go back over here
and look very carefully, you'll see
that the curved arrow is pointing
to this tiny little structure, which in fact is the bladder
that is decompressed by this larger structure
that has the divide down the middle and the fluid level.

Here's another case. You've got a pelvis of the fetus.

You have 1, 2, 3, 4 fluid filled things
and looking at them, two of them have a fluid level.

This is obvious and this is subtle,
but it was actually there
and I'm gonna let you read figure legends in your own time
because I wanna keep showing examples
of this sort of appearance.

Here's another fetus
and we have all of these strange looking fluid
filled things in the pelvis.

Here's these two fluid filled things on the coronal image.

So here's baby's bottom, here's towards the head end tubid
of structures that seem
to run cranial cordal dividing soft tissue wall fluid level.

What is going on
and why is there free fluid in here in the fetal abdomen?

Well, a cloacal malformation
or a persistent cloaca is rare enough
that it's only seen in one of 20,000 live births,
but it's a severe anal rectal malformation.

And what happens is that the bladder, the vagina
and the rectum all come together in a common cloacal
chamber, which is very small
and it usually opens onto the perineum by a single opening,
which can be stenotic.

So urine forms in the bladder
and refluxes back into the vagina, which is distensible
because the vagina is in connection with the rectum
and colon urine and meconium mix in the standard vagina.

And that's what forms the fluid level.

And the issue about cloacal malformation is the long-term
outcome for these babies.

The hydroco can obstruct the bladder drainage
and cause hydronephrosis
and that must be drained as soon as possible
after birth to allow the kidneys to recover.

And if the peroneal channel is very short,
then there is a good likelihood of maintaining
continent in the infant postoperatively.

But if that channel is longer, then the chances
of continence are much less
and it's also less likely that the child
and subsequent adult will be able
to have a voluntary bowel motion.

This is a thing to be aware of
and a pitfall in a case
where we missed is we had a fetus transferred at
about 36 weeks.

There was a large fluid filled structure
in the fetal pelvis.

The umbilical cord came in, the umbilical arteries seemed
to go around the structure.

There was anhy Neos at the time
without obstructed membranes.

And in hindsight we saw this fluid level,
but at the time we did not know,
the fluid level sign
and we also did not know the gender of this infant.

Therefore the assumption was made
that this was posterior urethral valves
with bladder outlet obstruction causing secondary renal
insufficiency In Anhydrase.

When baby was born, there were female external genitalia
and a transabdominal scan of the infant showed in fact
that the bladder was small and decompressed
and this large fluid filled structure was
a distended vagina.

This is the cervix in the vagina,
this is the urine and meconium level.

So something to be aware of and be very concerned about
because of the long-term consequences for the child.

Occasionally you can get an isolated hydroco
and in that case you will have a cystic pelvic mass which is
the fluid-filled vagina and sometimes fluid-filled uterus.

And here's the bladder vagina uterus on ultrasound.

Similar on fetal MRI.

Here's the vagina, very distended
because of an intact hymen causing accumulation of fluid.

Here's fluid in the uterus.

In that case you don't see the fluid fluid level
because there isn't necessarily mixing
of the meconium and urine.

But even in the absence of a cystic pelvic mass,
you should worry about a cloacal malformation if you have a
combination of genital urinary lumbosacral
and bowel abnormalities.

And if you do not have hydro culpas,
you can have a cloacal malformation without
the cystic pelvic mass.

So we're never going to be a hundred percent at
diagnosing this entity.

But if you see these unusual fluid fill collections in the
bladder, you need to be aware of what to look for next.

Anal Atresia

Along the same spectrum, anal atresia is another diagnosis
that is hard to make in the fetus and
because the obstruction is low, there usually isn't a lot
of dilated bowel because the intestinal mucosal surface is a
very effective surface for fluid absorption.

So the baby swallows fluid,
fluid is absorbed along the GI tract
and there is not the marked distension that we expect
to see in geal or I atresia.

Here's a 3D external genitalia. This is a boy.

They can have the blue cake at the gender reveal party,
but notice you can actually see the anal opening on
that same reconstruction on a 2D image, you see
what we call the anal dimple
and the hypoechoic muscle surround the echogenic mucosa
and this is a very characteristic appearance
on an axial image.

If you turn coronal through the rectal canal,
you will see the muscular walls
extending up into the pelvis.

And again the echogenic rectal
and anal mucosa in the center
of the hypoechoic muscular wall, MRI
with T one weighted imaging shows meconium
as being very bright white.

And you can see the subcutaneous fat is also white
so you see the buttock fat, buttock fat, the skin opening
and the bright meconium in the rectum.

Here's some examples of fetuses with anal laresa.

This is actually an autopsy MR
and you can see that there are fluid filled structures in
the pelvis but there is no rectum coming down in
front of the sacrum.

Here you have a longitudinal section along the pelvis
and you actually have a distended rectum,
which is relatively unusual.

Here's an example where there were distended bowel loops
and they were little echogenic foci within the bowel loops.

And those are what are referred to as meconium marbles.

This occurs if urine and meconium mix
and you get little calcified areas of meconium.

So if you see dilated bowel loops
that have echogenic foci within them, this is an indication
that there is a vesco colic fistula which is usually in
association with anal regia.

And here is a clinical example showing the very smooth flat
perineum of the baby.

There is no normal anal opening.

And in a small series that we reviewed at the University
of Utah, we found that it was never an isolated finding.

So if you are looking at the genital,
you can't see a normal anal dimple.

Go back and look for other abnormalities in the lumbar spine
and the pelvic organs to clarify 3D,
normal external male genitalia, normal anal opening
3D with hypos staus scented testes,
flat perineum 2D, nice anal dimple with the donut appearance
of a hypoechoic muscles with echogenic mucosal folds.

And here is this sort of unusual amorphous appearance
of just parallel skin folds but no distinct anal dimple
and anal atresia itself is not as rare
as cloacal malformations.

More importantly in my opinion, is the fact
that if you have a child with anal atresia, there's a three
to 4% recurrence risk in future pregnancies.

So moms are going to be very keen to know
that the next pregnancy is not affected.

They're very rarely found in isolation.

And so the importance of
identifying the normal anal dimple is if you can't see it,
you need to look carefully for other findings
and these babies require surgery at birth.

Here again is the clinical photo.

There's also associations with abnormal external genitalia
and this is just another view across the perineum.

This is the scrotum, this is the short penile shaft
with the curvature
and the glands opening inferiorly, with hypos,
BEUs and corde.

And this is a 2D example of a male fetus with hypos BEUs
and urine was trapped under the foreskin.

So we always saw this bubble appearance on the end
of the penile shaft during fecal ultrasounds

moving on from the down their region
to the anterior abdominal wall.

We all know that abdominal wall defects like gastroschesis
and unfail are easily diagnosed in ultrasound
and have certain associations and connotations,
but there are some more unusual abdominal wall defects
that are more complicated
and poor old Tom waits had a bad liver
and a broken heart and there was stuff
that the Beatles wanted to get back.

And I'm going to show you the type of abdominal wall defects
where there's a lot
of stuff hanging out where it shouldn't be.

Abdominal Wall Defects

Bladder Exstrophy

So bladder extrophy is that the bladder, instead
of being a pouch that contains urine,
is open onto the anterior abdominal wall,
therefore there's no fluid filled structure that we see
as the bladder and the bladder mucosa makes a lumpy bumpy
surface to the anterior abdominal wall.

In this clinical case, this is an umbilical hernia.

This is the ted bladder mucosa,
this is the hypoplastic penis
and here is the scrotum with under descended testes.

On a sagittal ultrasound image, you'll note
that the cord insertion is somewhat lower than usual.

You typically expect it to be about up here
and we don't have a nice clean skin echo.

Below it we have this lumpy,
bumpy appearance which is the ted bladder mucosa.

On an axial image you see the umbilical arteries,
the bladder should be between them
and that should be seen as a fluid filled structure
and we don't have a fluid filled structure here.

And we also have this sort of protuberant
or poochy appearance to the lower abdominal wall.

Here's a 3D reconstruction.

So this is one of the fetal legs.

This is the other fetal leg, this is the scrotum.

You have a bifid penis.

There's the cord insertion at the apex
of this protuberant soft tissue mass,
which is the verted bladder.

And on MRI you can see again
that the anter abdominal wall is sort
of irregular and indistinct.

We see the tip of the spine coming down
so the sacrum is present
and we can see on a T two weighted image
that the rectum is low in signal.

On T one weighted images, this would be bright so
that there is an abdominal wall defect
with bladder extraphy.

The bladder is averted but the colon is intact and present.

Cloacal Exstrophy

A more complicated version of
abdominal wall defect is cloacal, extrophy
and embryologically.

The GI gu
and genital tracts all end up together in a cloaca.

If the cloaca does not open
normally onto the abdominal wall, you get a cloacal exstrophy
and this is thought to be due to premature rupture
of the cloacal membrane
before the cloaca itself divides to form separate genital
and urinary tracts.

What happens in that situation is again,
there is a low anterior abdominal wall defect.

The cord insertion is at the apex of the defect
and there is often a membrane bound component
containing bowel loops.

The bladder is Ted and in two halves.

So one hemi bladder is on the right side,
one hemi bladder on the left side
and between the two bladder halves there are
ted free floating bowel loops
and it is this bowel loop hanging from the bottom
of the defect that has been used
to coin the term the elephant trunk sign.

So this is an example of a baby who was transferred to us
for care to have delivery at our hospital, which is adjacent
to the local pediatric hospital.

And the diagnosis was gastroschesis. We are scanning.

Here's placenta, here's baby anterior abdominal wall,
here's the cord insertion site.

And you can see that there are bowel loops that are outside
of the abdominal cavity
but there appears to be a membrane covering
and that is a little odd in
that gastroschisis should be free floating bowel loops.

When we look more at baby, we identify the aorta
and the aortic bifurcation into common iliacs.

The umbilical arteries arise from the internal iliac vessels
should surround a full filled bladder,
but we do not see a fluid filled structure here.

We do see some rather dilated bowel loops,
however that can be okay in the third trimester.

And the perineum of the fetus looks a little unusual.

We kept looking here is the spine
and coming down from the lumbosacral area there's a very odd
kink to the distal spine.

This structure is an ice cream sandwich appearance
and this is a lying down adrenal which indicates
that there is not a kidney in that renal fossa
and we didn't find a kidney anywhere else.

And looking across the fetas perineum
again, here is a buttock.

Here's this odd skin fold.

We're not sure if those are unusual labia
or an empty scrotum.

And once again that very prominent dilated loop of bowel.

We did an MR and we found
that the kidney we thought was absent was in
fact not absent.

It was not in the normal position in the renal
faucet, it was a pelvic kidney.

You can see that the buttock fat is very easily visible
and we don't see an opening for the anus.

We see a linear striation
but not a clear opening in a sagittal T one image.

This is the spine, this is the liver
and we would expect to see bright
meconium in a normal rectum.

So in this fetus we have
what is actually a cloacal exstrophy.

We have an anterior abdominal wall defect which was membrane
bound with the cord insertion At the apex
we have no normal bladder because the bladder mucosa is Ted.

We had bowel loops outside the abdomen
and we had anal atresia and a bifid scrotum.

And as you can see this is an unpleasant surprise
to have in the delivery room
and it's important to try if possible
to make the diagnosis before delivery.

Body Stalk Anomaly

Another type of abdominal wall defect to be aware
of is the body stalk anomaly.

And in this situation the cord is not identified
because it doesn't form normally
and the fetal peritoneum is actually open out
and reflects onto the amn
and the fetal abdominal wall is adherent to the placenta.

This is a lethal malformation, this cannot be repaired.

So here's an example here is the placenta.

Here's liver and heart.

The rest of the fetus is out of the picture,
but that is to show you
that the abdominal organs are adherent
to the placental surface.

You look everywhere with color doppler,
you see no normal free-flowing loops of bowel,
just the short bowel adherent again to the placenta.

And the fetus often has a marked scoliosis
because they are fixed from the anterior abdominal
wall to the placenta.

The upper extremities in the head are mobile,
the lower extremities are mobile,
but the fetus is always anchored
to the placenta at the level of the anterior abdominal wall.

Here's another good correlation.

Here's an ultrasound image with baby's head, baby chest,
some lower extremities
and the baby being anchored to the placenta.

And here's an autopsy correlate with this acute kyphosis.

The anterior abdominal wall is opened,
the viscera are adherent to the placenta
and there's a very abnormal short umbilical cord.

So when thinking about anterior abdominal wall defects,
your first step is to check
where is the cord insertion site.

If the cord insertion site is at the normal level
and you still have a defect, then you want to see if it's
to the right of the cord insertion
with free floating bowel loops.

And it's more like to be gastros hetus.

The defect can be on the left
but much more typically it's on the right if the defect is
below the cord insertion site
and you don't see extruded bowel,
but it does look as though the cord is going into intact
abdominal wall skin.

Think about bladder extrophy.

If the cord insertion is abnormal, IE on two a membrane.

Um, you then have the options of valil versus penology
of cantrel versus bands versus cloacal exstrophy.

And if the cord insertion is abnormal
and the fetus is fixed in relation to the placenta,
then think about body stalk.

And the key finding in body stalk anomaly is
that you do not see any normal free floating loops
of umbilical cord.

Lower Extremities and Skeletal Dysplasias

Moving on, we're now going to talk about lower extremities
and short people.

I think short people are okay, I'm five foot three,
my six foot two son likes to tell me I'm very annoying.

But people come in all sizes and shapes
and one of the things we do looking at fetal biometry is we
measure the femur length to assess gestational age.

One of the many, many sonographic criteria
for down syndrome is a short humerus or a short femur.

And an important thing to remember is that the short femur
as a sign of down syndrome is not percentile
for gestational age.

There is an equation in which the femur length is
related to the BPD and a number is produced
and it is the number that indicates whether
that fetus is at increased risk
or not as an isolated finding.

Short femur is relatively non-specific
and nonsensitive for down syndrome, but if you see it
and it marks the fetus in question as high risk, go back
and look for all of these other things
that may be seen in Trisomy 21.

What if it's an isolated short femur?

There is a condition called proximal focal femoral
deficiency, although it can be bilateral more often than not
it presents as a single short femur.

And this is an example,
here's a normal appearing femur on one side
and on the other side it's shorter.

This measures 4.7 centimeters versus 5.3.

And you'll notice there is an acute mid shaft angulation.

This is an x-ray of the baby at delivery
and you can see normal femur, short femur.

There's a very variable presentation from a mildly short
femur to an almost absent extremity.

And obviously the outcome for the individual
affected infant will depend on how severe the shortening is.

This is an example of a 3D reconstruction giving the
perspective of the normal lower extremity
and the shorter lower extremity,
which you can see this femur is much
shorter than that femur.

And depending on how severe the limb shortening is,
the surgical approach may actually be amputation
with fitting a prosthesis.

On the shorter leg side, if you have a short femur
and you've looked for down syndrome
and you've looked to make sure
that it's not an asymmetric isolated thing, look at the rest
of the baby because it may be an indicator
of a skeletal dysplasia.

And one of the most useful things to look at is the spine.

This is complete lack of ossification in the spine
and the fetus with ACH androgenesis

fatal skeletal dysplasias are numerous
but the lethal ones are associated with small size chest
and the lethality comes from pulmonary hypoplasia
and inability of the child to breathe when it's delivered.

So here's the chest, here's the protuberant abdomen.

The abdomen is normal, the chest is small.

And here's an axial image through the fetal chest.

And here you have these curved fractured ribs in a fetus
with osteogenesis imperfecta.

And here is an autopsy x-ray of a fetus
with severe platy spon.

The vertebral bodies are very shortened
and this is a fetus with ana euphoric dysplasia.

So in a quick overview of skeletal dysplasia approaches, one
of the useful things to measure is to compare the length
of the femur to the length of the foot.

If that ratio is less than one,
it suggests a skeletal dysplasia,
then you look at all the long bones, measure them
and correlate with gestational age
four plus standard deviations.

Below the mean means that the bones are really short
and the more likely you are to have a
potentially lethal skeletal dysplasia.

Sometimes the bone shortening is seen very early in
gestational and typically that's
with the severe perinatal lethal forms.

But achondroplasia for example can have progressive
romi limb shortening as pregnancy progresses.

The size of the chest is important for outcome.

Look at the head shape
and ossification to identify things like thanatophoric
versus osteogenesis imperfecta.

Look at the spine, look at the hands and feet.

Sometimes the finding like mitten sinally will help take you
to a specific diagnosis.

The bad skeletal dysplasias are the ones
that are perinatal lethal
and they have onset early onset severe short limbs.

The chest is small, there may be fractures
or bowing of the long bones.

The cloverleaf skull as seen in thematic foric dysplasia.

Hydros is always a bag prognostic indicator.

And another FEMA length to AC ratio less than 0.16 tends
to be associated with bad prognosis.

Brain Abnormalities

Moving on to our next area of concern.

This is about brains
and Eminem classified himself as brainless.

I can't say I disagree,
but again, some of the younger listeners might think
that I'm just being an old fuddyduddy.

So brains evaluation of the fetal brain is a huge part
of the routine second and third trimester ultrasound.

And in this talk we're going to specifically focus on
what I call watery brains.

And that is where the fetal head contains largely fluid
and not much normal brain.

This is important because the head can be large
and depending on the potential outcome of the pregnancy,
a discussion needs to be had with
that mother about delivery plans,
about monitoring in labor about whether
or not a C-section is to be performed.

And remember, if a C-section is performed,
the lower transverse C-section is fine
for a normal size head,
but if the fetal BPD is enlarged up to 13
or 14 centimeters,
either a classical C-section may be required
or an extended incision which will then have
implications for future pregnancies including whether
or not mom can labor again.

So I like to go through the brain systematically
and decide if I can see a normal midline, if I see a cyst
as opposed to a fluid collection.

If I can see the cerebral hemispheres
and if I can see the cerebellum.

First question, do you see a falx?

If there is no falx present it's generally going
to be an early embryological insult.

There's a condition called a
cephalic in which the pro cephalon, which is one
of the very early precursors
of normal brain development in the neural tube does not form
and therefore most of the normal brain does not form.

And here you have the ossified skull vault, no falx,
no brain head, full of water.

We do see some posterior fossa and hind brainin structures
and the face is abnormal
because the face embryologically develops at about the same
time as the brain.

And this fetus has no normal orbits,
no normal nose.

Here is another example of the same entity, a pro cephalic
and you can see on the mr the profile is very abnormal.

You'd expect to see a nose, you would expect to see a globe.

And we do not. We do see some cerebellum,
we do see some brain stem.

The posturing of the upper extremities in these fetuses is
very typical with this sort of radial clenched hand.

This is an autopsy specimen
and you can see that this is the floor
of the frontal brain.

This is the bivalve cranium.

This is looking down into the posterior fossa
and there is no super tentorial brain.

A cephalic is a slightly less severe version
of the same thing in
that the pros cephalon embryologically divides
to give you the t cephalon and die cephalon.

So in at Cephalon, the pro cephalon was there
but did not undergo its normal division.

And again, this is a very old case
and it was quite early scan, it was 17 weeks.

We could clearly identify cerebellar hemispheres and verus,
but we could not see normal super tentorial brain could not
see normal facial features.

And there were several skin tags
on at Anencephaly.

You do have some brain tissue but it stays very amorphous
and doesn't undergo the normal development
of cerebral hemispheres that we expect.

This was the biometry.

You could see that the abdominal circumference was normal,
but the BPD and head circumference were very, very small
for gestational age.

In this case an amniocentesis was performed
and this was a 13 Q minus deletion
and the pregnancy was terminated
and this is actually the autopsy specimen of that brain.

And again, just like in a pro cephalic, the positioning
of the upper extremities is abnormal.

Another condition in which the falx is not identified is a
low bar holo cephalic.

And no matter which way you look at the brain,
it appears quite round in shape.

There is this blob of tissue
that is the fused thalami super tentorial brain is
essentially all fluid filled.

Again, the face is abnormal, no normal globes.

And in profile you can see there's an absence
of a normal node
and this is a low bar ho of proce on an autopsy specimen in
that you have pros and cephalon
but you do not divide into your two hemispheres
and you have a continuous mantle of brain
with a large fluid filled space in the center.

All of those carry a bad prognosis.

Moving on to then if you do identify a falx,
the next question after is there a midline present is
how much brain do I see?

The condition known as hydrocephaly occurs when normal brain
development happened
and then something occurred in the pregnancy
to cause destruction of the super tentorial brain.

And it's thought to be
really a catastrophic hypoperfusion.

Some sort of vascular accident occurs
and the cerebral hemispheres are no longer profused
and dissolve an atrophy over time so
that when ultrasound is performed, the falx marks the midline
but there is no normal brain tissue in the
super tentorial area.

And here again an autopsy specimen with the bivalve cranium,
you can see that there is only fluid
and no normal brain above the tentorium.

Here's an example on MRI
and you can see this is axial sagittal and coronal.

You can see that the falx is present, falx is present,
there are little bits of debris
of super tentorial brain tissue.

But note that the profile here.

Here's the normal nose, upper lip, lower lip.

And there were two normal globes in this particular case.

Mostly we counsel patients that hydrocephaly is lethal,
there are scattered case reports of survival,
but obviously the cognitive outcome is extremely poor.

A condition that looks quite similar in some ways is
bilateral giant open lip scarcely.

Here is your midline echo, here is brain.

But you'll see that there is a very large defect extending
from the inside of the skull vault back
to almost the midline echo.

And here's the MR of a similar situation.

Now unlike hydrocephaly,
bilateral giant open lip schizo cephalic is not considered
to be lethal, but the neurological outcome is poor
and many of these children will have seizure disorders.

So if this diagnosis is made early enough,
many families would choose to
end the pregnancy rather than move forward
with a long-term impaired child.

So thinking about the prognosis of these
what I call watery brained, it's very important
that we pick out the group that have a lethal prognosis so
that those moms can be counseled about mode of delivery,
ideally have a vaginal delivery
before the head becomes too large to allow it
and avoid anything like a crash cesarean section.

These other conditions semi lobar cephalic is less severe
than a lobar ischemia of the brain.

Schizo anencephaly a condition called avid that we described
with a large interhemispheric cyst fused fornix
and adot stenosis or other conditions.

We don't have time to go into in detail here,
but all of them present with a large amount of fluid
above the tentorium
and all of them have poor developmental outcome

Facial Abnormalities Associated with Brain Malformations

along with the brain goes the face.

And we mention this because embryologically,
they're the same in the delivery room is when bonding
sometimes occurs.

And I work in a society where
patients will often carry a pregnancy
with a bad brain malformation.

Even though they know the prognosis is poorer
because culturally termination
of pregnancy is not acceptable.

One of the things that I have learned over the years in
discussing the with these moms is that they really, really,
really want to know what the baby's face will be like.

And to give you an example of a few cases that we had,
this was a baby with a dandy walker malformation, agenesis
of the corpus callosum, huge into hemispheric cyst
but only one normal eye.

Mom was not at all concerned about the brain malformation,
but she was devastated to know that there was only one eye
in this case there was a normal globe on this side there was
a fleshy mass which turned out to be a dermoid on that side.

But beneath this fleshy mass there was no orbit
and no eye on that side.

And again, mom was extremely upset.

Here's an example of a trisomy 13 fetus with microphthalmia.

Here's a case. This is the condition we refer to as avid,
where you have asymmetric ventricular magaly.

The asymmetry is caused
by an interhemispheric cyst in contact with the ventricle
and there's always dysgenesis of the corpus callosum.

This baby is profoundly developmentally delayed.

Here is the appearance with the normal globe
and anophthalmia on this side.

And here is an MR at birth showing
that there is a normal G globe in this side
and there was nothing in this orbit,
just some residual fatty tissue.

And the problem with anophthalmia is it's very difficult
to reconstruct and that side of the face grows differently
to this side of the face.

So these babies become progressively more abnormal looking.

And for the parent this is often far more disturbing than
the developmental delay.

Complications of Twins

We're gonna do norm four
and five together, which should tell you
that they travel in pairs.

We're gonna talk about some complications of twins
and sometimes you say two for the price
of one is a good thing,
but I prefer Elvis's modality with the double trouble.

So what can go wrong with twins?

Well, they don't always share very nicely.

And the big issue in twins is chorionicity
because chorionicity determines prognosis.

This is a nice bright echogenic ring.

This is a nice bright echogenic ring.

Two choon, therefore d chorionic twinning.

Each baby gets its own placenta
and this is good nobody has to share with anybody.

Over here we have one bright letic echogenic corion,
two very delicate amn.

Here's one, here's the other two yolks Acts two embryos.

So these are monochorionic but die amniotic twins and
therefore they have to share a placenta.

So they're both getting their
sustenance from a single source.

And in this case we have a single chorionic ring,
we have a single amnion, we have a single yolk sack,
but we have two discreet little embryos
and both of these embryos had cardiac activity in real time.

So these then are mono amniotic twins.

And not only do they have to share a placenta, they have
to share the same room in the uterus,
they have no privacy at all.

These guys at least have their own little sack
to hang out on even if they have
to eat from the same kitchen.

So how do you determine coty and amnesty?

And as I showed you in the first trimester, it's very easy,
it gets much more complicated if you see twins
for the first time in the second trimester or the third.

And one thing you can look at is fetal gender.

If the genders are different, then the twins are dizygotic
and by definition di chorionic.

If you see two separate placentas
for sure you're di chorionic,
but sometimes the placentas are implanted side by side
and look like a single mass thick membrane versus thin
membrane is all well and good to talk about.

But there are no actual numbers.

Clearly this is a thick membrane
and this is a very thin membrane,
but it isn't always as easy to tell.

And the twin peak sign is
where you see chorionic tissue going up in
between the inter twin membrane into make this sort of wedge
or lambda or peak sign.

And while the absence does not exclude dicho ty, if you
see it, it is 94% sensitive to say that the twins
with the twin peak sign are die chorionic.

Why do we care so much?

Well, remember I said if you are monochorionic you have
to share a placenta
and if there's unequal placental sharing,
one fetus can be growth restricted
and the other can grow normally.

Or sometimes there is vascular shunting in the placenta.

And what that means is occasionally you have a situation
where you can have a donor twin and a recipient twin.

So the donor twin sends blood theoretically toward the
placenta to get oxygenated,
but the umbilical artery from the donor twin connects
directly to the umbilical vein
of the recipient twin creating a shunt.

Then less blood comes back from the placenta
to the donor twin who becomes oli gmic.

And if you're oli gmic, you have less perfusion,
less fluid going
to your kidneys means less urine production means
oligohydramnios, less blood coming back from the placenta
means you don't grow as well.

On the other hand, the recipient twin
who has his own circulation going back
and forth to the placenta plus a chunk
of the co twin's blood coming into his circulation is
actually hypervolemic and then gets overload
and potentially can develop a cardiomyopathy.

And because there's marked increase in the circulating blood
volume, there's thought to be increased renal profusion,
increased urine production and
therefore poly hydros trap stands
for twin reversed arterial profusion.

And this is a different type of shunt between the twins.

And what happens in that case is you have an artery
to an artery shunt.

So the pump twin is sending blood
to the placenta via its umbilical arteries,
but instead of going into the placenta
to oxygenate the blood goes across to the cot,
twin's umbilical artery
and goes back up the umbilical cord into the cot twin.

And if you remember where the umbilical arteries arise,
they arise from the internal iliacs.

So the blood going into the trap
or the reverse arterial perfusion twin is going
backwards into the fetus.

It is already deoxygenated blood from the co twin.

It goes in at the umbilical cord entrance
and selectively peruses the lower extremities.

Here's an example of a placenta.

This is the cord of twin a cord of twin B
and there is this vessel connecting across here.

Twin B was a twin reverse arterial profusion fetus
that was treated with radio frequency,
which is why this cord is small
and twin A in this case did well and was delivered at term.

You can see that this is a very unusual appearance
and this is not compatible with life,
which is why it's important to recognize
because if not recognized,
the pump twin can develop a high output situation
and be very much in trouble
and a situation where there is nothing that can be done
to save this twin.

Therefore, if you can disconnect this shunt,
this fetus can go on about its
own business and grow normally.

And this fetus is incompatible with life anyway.

So if you look at twins, you have to identify the ity.

If they are monochorionic, you look for the combination
of oligohydramnios in one sac
and polyhydramnios in the other as an indication
of twin twin transfusion syndrome.

If you see any anomalous monochorionic fetus,
check the direction of the umbilical artery flow.

If the umbilical artery flow is going toward the fetus,
that is a reverse direction
and that indicates trap syndrome,
which the trap twin cannot survive.

And it's important to get radiofrequency ablation
of the anomalous twin so
that the pumped twin can then continue to grow.

Normally if you have connections between the twins
and one twin dies in utero for whatever reason, all
of a sudden the surviving twin has its blood volume going
into the vascular bed that previously accommodated to
and that results in an acute hypotensive episode.

In the survivor, the condition was initially referred to
as twin embolization syndrome
because it looked like you had ischemic event in the brain
or the myocardium of the surviving twin.

But it doesn't make sense
that a dead twin could embolize tissue into the circulation
of a live twin, which is why it's now accepted
that it is an acute hypotensive event in the survivor as all
of their blood volume moves into the entire vascular
bed for the two twins.

And this is an example of increased echogenicity from
periventricular leukomalacia from a bleed in utero in the
surviving twin of a monochorionic pair with demise
of the other twin mono amniotic twins not only share a
placenta, they are in the same space.

They can swim around each other
and they can get their umbilical cords tied in a knot,
which is not good for profusion
and that's why the mortality in mono amniotic twins is
thought to be so high
because the twins get their cords knotted
as they pull away from the knot, they limit circulation

And it is thought that these cord accidents are the result
of in utero demise.

Fetal Heart Evaluation

Moving on to number three,
what are we gonna talk about now be still my beating heart.

The four chamber view is a rooting part of second
and third trimester ultrasound.

And in fact now the AIUM recommend
that you should obtain outflow tract views.

And I know that at 20 weeks the fetal heart is the size
of a dime and it's beating at 160 beats per minute.

And it's really hard to look at.

And I will be honest, I'm scared of fetal hearts,
but if you have a systematic approach to evaluation
of the four chamber view, there are many, many things
that you can see.

And if you can see a normal four chamber view,
you can be comfortable that you're excluding a certain
number of congenital heart disease cases.

And if you see normal outflows you can exclude even more.

So we're gonna talk about specifically what do we do
with the four chamber view.

The first thing you have to do is make sure
that the heart's on the correct side of the baby.

And every time you scan you see where the head is,
where the spine is, decide which side
of the fetus is closest to the anterior abdominal wall
and then check that the cardiac apex
and the stomach are on the left of that fetus.

That is the normal cardiac citus.

If the heart
and the stomach are on the right side of the baby,
that is cytosine versus it's a right left inversion
and it tends not to be associated
with congenital heart disease.

So although it may have complications in life such
as conditions as cartage syndrome in the fetal world,
it's much less concern
and lot likely to be associated
with congenital heart disease.

If you have any other combination of these findings,
then you have cyto ambiguous, also known
as the hetero taxii syndromes.

And the hetero taxii syndromes are associated
with extremely complex congenital heart disease, which needs
to be evaluated by experts either in the maternal fetal
medicine or fetal echo world, ideally by both.

Here is a cardiac axis.

Uh, you draw lines through the chest to measure an angle.

I'm going to show a picture of that in a moment.

You should also just look
and see, can I fit three of those hearts into this chest
and look at the thickness of the myocardium
and it should be visible, but it shouldn't be encroaching
upon the lumen of the chamber.

So here's the axis.

You draw a line along the plane of the ventricular septum
and you draw a line by dissecting the fetal chest.

This line should go through the left atrium
and the right ventricle and the angle
between the two lines should be 30 to 45 degrees

are the chambers symmetric.

Your two ventricles should be the same size.

Your two atria should be the same size.

This is the moderator band which
identifies the right ventricle.

The right ventricle should be the anterior ventricle
moderator band anterior ventricle, right ventricle.

This is correct. The posterior ventricle is the smooth
walled one, which is the left ventricle.

The ventricular septum should be about twice the length
of the atrial septum.

The atrial septum should have a hole in it
for the frame val,

the AV valves are offset on the ventricular septum
with the tricuspid valve implanted more apically.

You identify the atria by the veins that drain into them.

And this is turning around to show the superior
and infra vena cava
entering the right atrium on an axial view.

If you watch carefully, you'll see the pulmonary veins
entering the left atrium.

And here's a NA just to show
that this can be done in real time.

So here is U heart,
you could fit three of those in the chest.

The axis looks good, it's about 45 degrees.

The AV valves are opening
and offset on the ventricular septum.

And there's one vessel behind the heart,
which is the descending aorta.

There should only be one there.

If there are two you need to worry about
as a discontinuation of the IVC.

This is a different case
and you can see that the heart is rather
too large for the chest.

You couldn't fit three
of these hearts into this chest circumference.

We have symmetric atria,
but the ventricles are not symmetric.

This is a smooth walled apex forming ventricle.

This is a very thick walled non apex forming ventricle.

And so just on the four chamber view,
you can identify the fact that this is an abnormal heart.

In fact, it was an infant with pulmonary atresia and
therefore needed further evaluation.

One of the reasons why it's so important
to pick up congenital heart disease
before delivery is
that we can do what's called maternal transport.

And that situation, the fetus in utero is transported
by mom to a tertiary center.

Delivery is planned
and baby is handed immediately from delivery,
whether it's a vaginal or a cesarean delivery
to newborn intensivists.

If prostaglandin is started,
it stops the ductus from closing
and then the baby is transported to the cardiologist
for urgent intervention if necessary.

If the ductus closes,
sometimes you disconnect the arterial circulation in the
aorta from the arterial circulation to the lungs
and induct dependent heart disease.

This is lethal. So it's very important to pick up on things
that can be seen on the four chamber view
and get these patients referred on to expert areas
where fetal cardiology
and maternal fetal medicine can form a birth plan for
that pregnancy.

Alternatively, in some situations such
as a hypoplastic left heart syndrome,
when families are informed of the prognosis, they may choose
to interrupt a pregnancy,
but they lose the ability to make
that choice if the diagnosis is not made
until late in pregnancy.

We also mentioned the cardiac axis and the axis is important
because if it's abnormal it means either the heart is being
pushed or it's falling into a place
where something else should be.

And I'm not going to go over these in detail,
but a chest mass can push the heart towards the chest wall.

If the lung is missing,
as in this case the heart falls toward the chest wall.

If there is con truncal malformation
or hetero taxii syndromes,
the heart will be in the wrong direction.

And in ectopia cords,
that means the heart is ectopically located.

In this case, there was an upper anterior abdominal chest
wall defect and the heart was protuberant.

In this case, the heart had decided it was going
to go live under the diaphragm
and had scooped out a little nest
for itself in the surface of the liver.

And neither of these cases survived
because in this instance,
although the child was live born,
when the surgeons were attempting
to get the heart back into the chest, they kinked vessels
and the child coded.

And in this case there was severe hydros in
utero which proved fatal.

Placenta Accreta

Now if anyone was paying attention, you know that I got
to number three and here I am going to number one.

So what happened to number two?

I have decided to do two number ones
because I think there's a number one way
of killing a healthy mom
and there's a number one way of killing a healthy baby.

So that's why I didn't make them one
and two, I think they're both number ones.

And the number one way to kill a healthy mom is
to miss a placenta accreta.

As the C-section rate increases the likelihood
of people having a placenta previa in a uterus
that's previously been scarred
by a cesarean hyster otomy is increasing.

And we are seeing more and more of this condition.

And this is an intraoperative photo.

This is the incision in the uterus
by which the baby was delivered.

And this is the lower uterine segment with all
of this bulging protran abnormal placentation.

We use the term morbidly adherent placenta now rather than
placenta accreta because accreta, accreta
and percreta are actually conditions that are seen
underneath the microscope.

And on imaging where you may be able
to make a confident diagnosis of perreta,
you cannot differentiate between accreta and in increta.

So the term morbidly adherent placenta
or placental adhesive disorders is preferred.

And this is what this looks like.

Here's the anterior myometrium.

Here is placenta, it's thick, it's in homogeneous,
it's causing a bulge.

In the lower uterine segment there is a placenta previa.

There are large vessels, again, large vessels all
through the placenta with very prominent vessels at the
bladder interface.

Big tornado vessels in the placenta
with abnormal spaces in the placental tissue.

A normal placenta is kind of a boring looking thing,
looks a bit like scrotum Test acute
ultrasound, thyroid ultrasound.

And none of those are ever gonna go in the scrapbook.

Most moms don't want a placenta scrapbook picture either.

But here it is very homogeneous gray scale.

It's a gas exchange organ.

It should have nice blood flow between the base
of the placenta and the myometrium.

Looking again at an abnormal placenta comparing to normal,
you can see here's this very homogeneous, bland,
mid-level gray echogenicity.

Here's the abnormal thick bulgy in homogeneous contour.

Here's the sub placental vascular bed for gas exchange.

And here are the abnormal tornado vessels all throughout the
placental parenchyma.

We can do MR as well. And as a radiologist, I do both.

I actually find ultrasound much,
much easier in the anterior placenta in a C-section scar.

And this is just to show you, this is an mr.

This is the same ultrasound.

You can see all the same anatomy.

Here's placenta, here's placenta, here's bladder. Bladder.

The placenta is going out
to the anterior abdominal wall musculature here.

It had gone through the uterine cirrhosis,
so this was placenta perreta.

But over on the ultrasound you can also see here's the
placental tissue.

And there is no normal sub placental hypoechoic zone.

The placental tissue is touching the uterine ci.

It can be helpful in some conditions
where there is an abnormal placentation in a more posterior
location, which is harder to see
because your acoustic access is limited.

And in this example, we could see a nice clear fat plane
between the back of the myometrium
and the sous muscle on this side,
but we could not see it on the right hand side
and we could not follow the iliac vessel flow void down into
the pelvis on the right as we could on the left
because we were concerned
that there was placenta paretta extending posteriorly
and encasing the vessels at the time of surgery.

In this case there was, a placenta perreta,
but they did not have to do a vascular anastomosis.

Here's a similar situation.

This is a sinia proven,
there's been prior uterine instrumentation.

Here is a reasonably normal interface between placenta
and myometrium
and we come down here, it all becomes very indistinct.

Here's the endocervical canal.

So if this is all placental tissue,
where is the normal myometrium coming out
to each pelvic sidewall?

We had all this unusual hypervascular,
amorphous material.

It looked like it extended side
to side from obturator internist to obturator internist.

And in this case there was actually a five centimeter mass
of spongy placental tissue extending through the uterus,
which was seen on the gross pathology.

Vasa Previa

So moving onto the number one way to kill a healthy baby,
the rivers of Babylon, the delta, the spreading vessels,

VA previa, vaso previa is associated
with certain conditions,
but in particular a ous cord insertion
or a ssur lobe are high risk entities
because the vessels have to travel from the main piece
of the placenta to the suction turt lobe.

And if they happen to cross the internal oths doing so,
that is placenta
or that is vasa privia in the situation
where you have tus cord insertion,
if the vessels run along the membranes
to get to the placenta.

And in doing so, cross the internal os.

Again, that is VA previa.

Here is an example from a two case.

This is the placenta,
these are the membranes being held up for the photograph.

Here's the umbilical vein. Here are the umbilical arteries.

And you can see that these vessels travel in the membranes
over quite a distance.

And this was actually not a case of vaso previa,
but could have been depending on where the placenta
and the cord insertion site were.

This is what it looks like on imaging.

There's a sign called the mangrove sign,
which has been used to describe this.

And you see the umbilical cord on color.

And then you see these vessels trailing along the membranes
like the roots of a mangrove tree.

Here on the CIC clip you can see you have the baby head,
you have the placenta, and you have this tangle of vessels.

So be careful that when you see a tangle of vessels,
it's not just elope of free floating cord.

And if you have a risk factor such
as a previous placenta preview or low lying placenta
or multiples or a centurion lobe, map out
where those vessels travel in the membranes
and where they go to.

Here's another example, transabdominal scan.

There's some placenta anteriorly, some placenta posteriorly.

There are vessels here
and they're crossing the general area of the cervix

On vaginal ultrasound on the cine,
you can watch here's the internal A of the cervix
and look at these vessels.

They're walking along the membranes right
beside the internal A of the cervix.

So this is vaso previa
and you need to put, pulse wave doppler on
and document fecal heart rate in vessels rather
than maternal heart rate.

Summary

So to summarize, the things that I worry most about missing,
starting at the bottom are ambiguous genitalia,
anal atresia, other abnormalities of the, genitalia,
the unusual abdominal wall defects,
because even though they're rare, they're very important.

Short femurs could be just stature in a five foot three mom
to being something like a lethal skeletal dysplasia.

Hydrocephalus is not a diagnosis, it's an observation.

If you have water on the brain, you need to figure out why.

With all multiple pregnancies, you need to assess the ity
and look for complications of mono ity.

The four chamber heart view is not something
that you just look up and watch beating.

You have to have a checklist.

And then you really need
to be careful about morbidly inherent placentation
or VAs previa because if this is undiagnosed,
women can bleed to death.

If this is undiagnosed, a fetus can bleed to death
before there's time to get back
to do an emergent cesarean section.

And while Bob Marley, they have had all kinds of songs about
what he worried about and
how everything was gonna be all right, even in Denver,
I don't necessarily feel that I can get enough medication
to help me stop worrying.

Don't be afraid to ask for help.