Non-Invasive Diagnosis of Fetal Anemia - SD

Introduction

My name is John Carlo Murray.

I am originally from Italy.

I've been in United States for more than 20 years now,

and I am an obstetrician, and my title is Professor

and Chair of OBS

and Gynecology at University of Tennessee in Memphis.

Today I will talk about fetal anemia

and how we can use ultrasound

to diagnose fetal anemia.

And I will tell you a little bit about the history,

how we came to diagnose fetal anemia.

Just with ultrasound.

Definition and Causes of Fetal Anemia

Fetal anemia is defined as an hemoglobin value

below the fifth percentile for gestational age.

There are many causes of fetal anemia,

however, in the United States, one

of the most uncommon causes of fetal anemia remains

red blood cell immunization.

Despite the use of rga,

which was introduced in 1968 in North America,

it today, it is estimated that there are approximately

4,000 cases of fetal anemia due to outreach,

hemolytic disease.

However, the RH is not the only cause of

red cell immunization

because there are many other antigens,

the so-called irregular antigens,

which may cause fetal anemia.

Think about K kid and others.

All immunization from irregular antigens cannot be prevented

by prophylactic administration of immunoglobulin

because they have not been developed

Historical Background

In 1941, Steiner

discovered the RH antigen.

It was approximately 10 years later that, Bevis

reported that the spectro automatic analysis

of the amniotic fluid could be useful in the antepartum

management of hemolytic disease of the neonate.

In 1956, Albert William Malali

performed his force amniocentesis.

In 1961, he reported

the Delta D 450 curve,

and two years later, he also reported his first

intraperitoneal fetal transfusion.

It was one year later in 1964

that Vincent Frida

performed the first intravascular transfusion

on a fetus anemic Aus at 26

weeks gestation.

What, Vincent Frida did is he performed the laparotomy

and his ster otomy.

He externalized one of the lower extremities

of the fetus, and he transfused the fetus

through the f femoral artery.

The procedure was successful,

but unfortunately the fetus died within 24 hours

from the transfusion.

However, two years later in Puerto Rico, Adamson performed

the first successful intravascular transfusion

on Anomic fetus

in 1968.

Thanks to the studies performed by Vincent Fried,

the RGA was introduced in North America, also, thank

to the help of the sinking prisoners

who helped for the study.

It was in early seventies that Carlo Valante,

an Italian who was working in New York at that time,

reported that Oscopy could be used

to diagnose open spina bifida

and to perform also fetal blood sampling.

After that, Charles Roddick in Europe and John Hobb

and Jeremiah Mahoney in the United States started to use

Oscopy to perform intravascular transfusion on Anomic Fe.

It was, in 1983 that Fernanda Dafo

reported described the technique for cord blood sampling,

under ultrasound guidance.

After this study, a period, the type defined

of anarchy started in fetal medicine

because many investigators all around the world started

to perform cord blood sampling,

and unfortunately, many times the procedure was unnecessary.

Limitations of Invasive Procedures

For many years, amniocentesis

and cordocentesis have been used

to diagnose fetal anemia.

However, both procedures are invasive.

Amniocentesis is invasive. It is not reliable.

Before 27 weeks gestation, we do not know what is the

optimal frequency of repeated sampling.

For example, if we do an amniocentesis

and the delta D 450 is in a safe zone,

we don't know when to repeat the procedure.

In a week, in two weeks, in four weeks, nobody really knows.

In addition, amniocentesis does not appear

to be reliable in kale sensitization

because with the kale,

the problem is not the hemolysis.

But the problem is the suppression of the

OID precursors at the level of the liver, spleen,

bone marrow, et cetera,

and am synthesis can also be associated with worsening

of maternal all immunization.

And here it is reported the L graph

with the three typical zones, one, two, and three.

And, and as you know, the l graph

with the L graph, we measure indirectly the bilirubin in

the amniotic fluid.

Therefore, if there is hemolysis, the bilirubin will

increase and also the value

reported here on the curve will increase.

Now, if the value is in zone one, the PHUs is non anemic.

If it is in zone two, the fetus is probably non anemic,

but is maybe becoming anemic.

And if the value is in zary,

the fetus is most likely anemic.

The green dots here represent the values

of the delta D 450 on a

fields who was anemic during

gestation, and he was an automic birth.

However, his mom underwent six amniocentesis,

so therefore six unnecessary procedures.

Now, the what about the cordocentesis?

A cordocentesis is more invasive than amniocentesis.

We do not know what is the optimal frequency

of repeated sampling,

and the cordocentesis may also be associated with worsening

of maternal immunization.

In addition, risks of cordocentesis are infections,

fetal bleeding, bradycardia, p om, and fetal demise.

Ultrasound Approaches to Diagnosis

For many years, investigators have tried to use ultrasound

to determine if the fetus was or not.

One of the parameters that was suggested was the diameter

of the umbilical vein.

Other investigators like

and have, suggested the use

of the spleen circumference.

Others like Alistair Roberts

and was suggested

as suggested the liver measurement,

the circumference of the liver.

Others like RAF

and Nicolini suggested

to look at the ascites.

At the end of the eighties, we came up with a hypothesis

and we said, if the phy is anemic,

the blood viscosity decreases

and the cardiac output probably increases.

The consequence of these two effects is

that the blood velocity must increase.

Doppler Ultrasound Concepts

And before I continue, I would like

to give you a few concepts in the optical ultrasound.

And in this slide, it is represented the relationship

between the, the cosign of an angle

and its value.

And as you can see, if the cosine of an angle becomes,

greater than zero degrees,

the value becomes smaller than one.

Therefore, when we want to obtain the blood velocity,

we need to make sure that the angle

between the ultrasound beam

and the direction of the blood flow is very close

to zero degrees, because if the angle is greater,

we will underestimate the velocity

because of the, the value.

As you can see, we will decrease.

Now with our machines,

we can either underestimate the blood velocity

or we can also overestimate the blood velocity

when we use an angle corrector.

In practical terms, it is not always easy to get an angle

of zero degrees, and that is the reason why

when we do doppler ultrasound, the fetus,

often we use indices which are angle independent.

Now, if the, blood velocity is direct

or is directed over the transducer, the waveforms,

the dopper waveforms will be represented above the baseline.

Whereas if the blood flow is directed away from the

transducer, the waveforms will be represented

below the baseline.

Here you can see the color doppler of the circular willis,

and the color red

and blue indicate the blood, the direction

of the blood flow.

Red here indicates

that the blood flow was directed toward the transducer,

and the blue indicates

that the blood flow in this case was directed away

from the transducer.

Here you can see flow velocity away from

of the middle cerebral artery.

To the question is the blood velocity in systole

actually is the PTO velocity, which is the highest point

of the waveform, which is in this case is s equal

to 56 centimeters per second.

And is this the real velocity of the blood flow in,

which it was obtained?

The answer would be probably yes,

because the angle between the ultrasound beam

and the blood flow, as you can see here,

the middles artery in red are very close to zero degrees,

and therefore these 56 centimeter per second is

the velocity of the blood flow.

Middle Cerebral Artery Peak Systolic Velocity (MCA-PSV) Technique

Here you can see the steps that we have described

at the beginning of the nineties,

but we did another study,

at two different institutions with Dr.

Abad in, six, seven years ago.

And these are the steps that we should use

when we want to measure the real blood velocity at the level

of the middle cerebral artery.

As you can see though, the, these are,

these steps are clearly defined,

but the most important concept is

that the middle cerebral artery should be imaged with

for its entire length as he reported,

and the wave from should be all similar to each other.

This is a small video clip.

It is an old video clip which shows the steps

that are needed to correctly sample the

middle cerebral artery.

Here you can see the circular Willis.

Here, there is the middle cerebral artery,

and as you can see, the middle cerebral artery is visualized

for its entire length,

and the sample volume is a place very close to the origin

of this vessel from the internal carotid artery,

and the wave from so should be all similar to each other.

Usually when I look at the blood velocity at the level

of the middle cerebral artery,

I repeat this at least three times.

When I see that I get a consistent value, I consider that

as the real value of the blood velocity.

Here you can see flow velocity wave from,

so the middle S artery with advancing gestation,

and here you can see the reference range

of the middle cerebral artery, peak systolic velocity

with advanced in gestation.

And the the green lines of, of course,

represent the reference range, whereas the, the yellow dots

represent the values from which the,

the reference range was obtained

In, in 1919.

In 1990, we did the study

and we, in this study we went

to look at the middle S artery peak systolic velocity

in s who were anemic cordocentesis,

and we plotted the values above the reference range.

And what we saw is that in many cases,

the blood velocity was above the upper limit of normal.

However, there were many other cases in which the blood

velocity was within the reference range.

We were a little bit disappointed when we saw this data.

However, we said the middle ceal artery peak historic

velocity as measured

by do ultrasound is increased in anemic osis,

and unnecessary procedures can be avoided.

There was something that we were missing,

and what we were missing, was the relationship

between the hemoglobin

and here is reported as a multiple sodo median

and the middle cerebral artery peak systolic velocity

reported as a multiple sodo median.

There was one of my former fellows, Ugo Oz,

who was a study with the midis,

and I remember that when I saw, when Ugo show me this graph,

I think that we realized what we had missed for a long time.

The concept is that if the pH is mildly

the middle cerebral artery,

p systolic velocity will not change much.

However, if the phy becomes anemic,

the blood velocity increases

and there is almost a linear correlation

between the velocity and the hemoglobin.

With this in mind, we organized a multicenter study,

which was conducted in

at eight different medical centers from all

around the world, and the first step was toan,

the reference range of fetal hemoglobin

with advanced ing gestation.

And here you can see the reference range

of the fetal hemoglobin.

The green dots represent the values

of from which the reference range was ofan,

and all these values were ofan.

At cordocentesis.

We also defined the anemia as mild, moderate, and severe.

After that, we went to plot the hemoglobin values

of obtained in 111 FES who underwent a cordocentesis

because based on traditional criteria, they were defined

to be severe anomic.

And what we found is this, first of all, we realized

that approximately 70% of the fetuses were,

had the hemoglobin value either in the normal range

or they were mildly.

And among the fetuses who had moderate to severe anemia,

30 40%

of them were hydro the red dots at the

time of the procedure.

Therefore, we were performing more than under procedure in

reality to detect to approximately to 20 fetuses.

And we were doing a lot of unnecessary procedures,

and the many fis were dying

because of an unnecessary procedure.

We also looked at the mids artery systolic velocity in the

old fes, and by using the cutoff of one point 50

multiple, so median, which was obtained to the

ROC receiver operating characteristic curve, we realized

that if we had the use of this cutoff,

we would have detected all the an osis

and we would have avoided approximately 70%

of the procedures.

In this study, we said the conclusion was

that the sensitivity

of the middles artery pick systolic velocity for detection

of significant fetal anemia is approximately a hundred

percent at to 12% false positive rate.

We also have found that in Cal immunization, the correlation

between mids artery peak systolic velocity

and hemoglobin is good.

And this is the curve

that we have used since we did our study,

11 years ago, where you have the median

and the one point 50 multiple solid median

you have on the y on the Y axis, the mids artery,

p systolic velocity,

and on the X axis gestational aging weeks

after that, there were many, investigators that said

that this is a good study,

but in a certain way, this is a retrospective study

because you have not used the middle cerebral artery to,

for time in a cordocentesis.

So, with this in mind, we organized another study.

Actually this was organized by Roland Zimmerman, one

of my friend who is a friend who is now chairman

of O-B-G-Y-N at the University of Zurich in Switzerland.

In this study, there were five tertiary referral centers.

There were 125 fetuses at risk for anemia,

and the middle ceal artery, p systolic velocity was used

for time in Cordocentesis.

In this study, we did not do a cordocentesis In 90

feis, we performed the 35 cordocentesis somewhere

unnecessary, and we missed two cases of anemia.

However, the interval between the last exam

and the, delivery, oh, and

and delivery was greater than three weeks.

Clinical Application and Follow-up

Up to now we have talked about the middles artery,

p systolic velocity that, can tell us if the PHUs has

or not significant anemia.

However, if we look at one value, when do we need

to repeat the another value?

If, for example, if FE is not anemic, do we need

to repeat the study in one week or maybe three weeks?

And this is the reason why we did another study.

We went to look at those

at the middle cerebral artery in Feis at risk

for anemia in fess who were not at risk for anemia.

We developed, we followed these feis longitudinally,

and here you can see the regression line of individual fess,

non anemic.

The black lines and the S regression lines of

DUIs became severely anemic.

As you can see, the slope of the two

of the curves is different.

Even when we went

to look at the phys were mild anemic at cordocentesis,

we found that the slope between the,

normal non anemic osis in Blake

and the mildly anemic fibrosis was different.

Okay, so we developed this graph based on this graph.

We repeat the scan between one and four weeks.

What we do today is this, if the the values,

we will obtain the mid cerebral artery,

peak systolic velocity in fis who are at risk for anemia.

At the week apart, we will obtain three values, and

after that we look at the, the regression line.

If the regression line is to the right of this green

dotted line, we repeat the scan between two and four weeks.

For example, if the patient is at 20 weeks gestation

with no history of a previous fetal, anemia,

and she has a title

of anti D 1 64 1 over 28,

and the regression line is to the right of this green

dotted line, we repeat the scan in a month.

We don't bring the patient back in a week or two weeks

because it is not necessary, whereas it is between the green

and the yellow red line.

We repeat the scan usually in one week,

and if it is to the left of the red line

and the middles artery, p systolic velocity is still

below the one point 50 multiple.

So the median, we repeated the scan in two

or three days to see if we can confirm the values or not.

Today, we are more rarely using this graph

because we just look at the trend

and by looking at the trend, I will say that

for the last probably eight

or 10 years, we have not missed any anemic

or severely anemic PHUs,

and we did not perform any unnecessary procedures.

There are many studies which have confirmed

that fetal anemia is a good tool for to use.

I'm sorry that the middle sal artery,

peak systolic velocity is a good tool, good to look

for fetal anemia.

Patient Selection and Technique Considerations

But I would like to ask some questions.

Which patients are candidates for the assessment

of the middle sal artery peak systolic velocity?

First of all, patients should be at risk for having an fetus

because if the fetus is not a risk, there is no reason

to look at the peak systolic velocity.

Where do we need to sample the middle sal artery?

Peak systolic velocity?

And we have learned that

by sampling the middle cerebral artery,

peak systolic velocity, soon

after its origin from the carotid, there is the lowest

intra and inter observer error.

How do sonographers systemologies achieve a good training?

Well, first of all, sonographers,

ologists should become familiar with the steps

for the middle cerebral artery,

p systolic velocity assessment,

and at least at the beginning,

they should contact the centers for advice.

Of course, centers with experience

is the delta D 450 better than a mid cere artery,

peak systolic velocity, or vice versa.

In 1997, we reported

that the middle cerebral art peak systolic velocity was at

least as good as the delta D 450.

This is this data were confirmed by, Perera

and by opus.

Actually, opus was the leader order of the,

for the diamond study group.

This study went to compare doppler

of the middles artery, peak systolic velocity versus

amniocentesis to predict fetal anemia.

And the study showed that the doppler of the mids artery,

peak systolic velocity performed a better in terms

of sensitivity, specificity, positive

and negative predictive value when compared

to the the amniocentesis.

And this I think was a really a great study.

Now, based on this to the question,

is the middle cerebral artery, p systolic velocity standard

of care for the diagnosis of fetal anemia?

I think that today the answer probably can be yes, it is,

it is at least in the United States,

and I will say many areas of the world has become

the standard of care.

Now, it is also true that people can, some people,

some investigators continue to do amniocentesis,

but I think that it would be very important today

to tell the patient that there is, if somebody wants

to do an amniocentesis, the patient should be informed at,

told that there is a test that is less

invasive than amniocentesis

and it is better than the amniocentesis.

And after that, the patient, of course,

can make the, can choose.

And I think this will be important to, to talk

to the patient because of, of legal issues

that could arise in the future.

Today also the American College of of o ob, GYN

as recognized the middle civil artery pick systolic velocity

as a good parameter to use in cases of fetal is at risk

for fetal anemia.

And what is to be the management algorithm

of fetal anemia today?

I think that it is synthesized here, the only,

and this can be found on many textbooks.

The only difference with the,

what is found still in some textbooks is that instead

of amniocentesis

or cordocentesis, we should report middle S artery.

Peak systolic velocity.

Sequential studies is the middle S artery peak systolic

velocity reliable in s previously transfused,

there is a study that is going on now organized by

Greg Ryan, and, he's a group in Toronto

and with, Nelson

and other fellows all around the world,

a problem will get an answer in,

four

or five years about this.

Although I think that today the most important concept is

that the artery pick systolic velocity is important to,

to diagnose anemia at the beginning, because

after that, I think that will be, in a certain way,

it's easy to manage anony failures

after that has been transfused.

Is the artery peak systolic velocity reliable

for the diagnosis of fetal anemia due to other causes?

And the answer is yes.

There are many, many studies now in the literature which

have reported that the mids artery

peaks historic velocity is useful in cases

of parvovirus infection, feto, maternal hemorrhage,

non-immune eyedrops in cases

of monoclonic twins following the death of the co twin

and in cases of twin twin transfusion syndrome

following the laser therapy.

Clinical Examples

I would like now to show you some examples to see

how we are using the middle S artery peak systolic today.

By doing in this way, as I said

before, we have not missed any case of severe anemic anemia.

I will say probably for more than 10 years now,

and we have not performed any unnecessary procedure based on

the CE artery historic velocity.

Case Number One

This is a case number one.

The patient was a 33-year-old, the gravitate three,

with an anti DO one over 64,

and she had an increased delta D 450 in the amniotic fluid.

The fetus was a reached positive,

and she underwent a cordocentesis at 22 weeks,

but this was unsuccessful.

The patient was referred

to our group at 22 weeks in one day,

and this was the Delta D 450

that had been done previously by another group.

And when she came to see us,

we gave her several option Tri cordocentesis, again, wait

for signs of eye drops

or look at the middle cerebral artery,

peak systolic velocity assessment.

She opted for the middle cerebral artery,

peak systolic velocity,

and the first value was below one point 50 M.

And after a month, approximately three month,

the value became, above one point 50 MOM.

At that point, we did a cordocentesis,

and the OZ anemic was 7.4 grams per

deciliter, the hemoglobin.

And here you can see the, the, the trend of the MSCA

of the mids artery peak historic velocity Following the

transfusions, as you can see,

after transfusion, the value drops decreases.

Another Case: Kell Sensitization

This another case, the patient was cal sensitized.

The unical titer was one of 512.

The PHUs because of an amniocentesis was K positive,

and the patient opted

for middle s artery systolic velocity assessment.

The first value was very close to one point 50 MOM,

but in a couple of weeks this value,

there was a sharp increase over the value.

We did the cordocentesis

and the, the hemato was 17%.

The patient, the baby was transfused, went to 31%.

The velocity decreased, and after increased again and

after decreased again after the cordocentesis.

Case Number Three

Case number three, this was a case of,

anti dfi and the value went from 1 28

to 1 0 512.

We started to follow the patient

with mid ceal artery peak historic velocity,

and the values were all below

the one point 50 multiple of media.

However, the title went to one oh 1024.

I think we continue to follow the patient with ceal artery.

We did not to do any procedures at that point,

although we became very nervous because of this value.

But the baby delivered a term.

And when the value was repeated in the ma,

it was one over 256

and the baby was an, an birth actually was 41%.

Case of Decreased Fetal Movements

The patient was a 28-year-old primi gra at 36 weeks

gestation with a decreased of fetal moments.

She had been seen in the office,

in the private office the day before,

and the NST was reported, was reactive.

She came back to the hospital day, the day

after, again, with decreased fetal movements.

Here you can see the, the typical cidal pattern,

but also we looked at the middle S artery,

peak systolic velocity,

and the value was 1 110 centimeters per second,

well above the, the one point 50 M om.

Anyway, the patient was delivered by C-section.

The hemato was seven percent.

Anyway, the baby was transfused and did well.

Conclusion

In conclusion, the middle cerebral artery systolic velocity

is an excellent tool for the diagnosis of a fetal anemia.

Many babies today will live an healthy life

because of a middle cerebral artery, p systolic velocity.

It is important to emphasize that the training

of sonographers and the sonologist is indispensable.

And thank you.