Let’s Get Biophysical! Ultrasound Assessment of the Fetal Well-Being - HD

Introduction

I am Dr. Anne Petrowski, private practice radiologist and section chief of ultrasound at Baptist Health South Florida in Miami, Florida.

Today I'm going to be talking about the biophysical profile and ultrasound assessment of fetal wellbeing.

I have disclosure as a consultant for Siemens.

Clinical Background on Antenatal Testing

Let's start with the clinical background on antenatal testing.

The perinatal mortality rate, which is rate of death within one week in the United States in 2012, is six out of a thousand.

55% of the perinatal mortality rate is stillbirth.

And of those stillbirths, 30 to 50% occur in low risk pregnancies.

However, in high risk pregnancies, it should be noted that the perinatal mortality rate is higher, at least tenfold at 70 out of a thousand.

So the question is asked what population benefits from antenatal testing and the overall goal of antenatal testing should be stated as to reduce hypoxemia and acidosis leading to stillbirth or hypoxic brain injury, which is manifest as cerebral palsy.

And sometimes that can come later in the child's life as they develop in a delayed fashion.

Tests for Antepartum Assessment of Fetal Wellbeing

What are the tests for antepartum assessment of fetal wellbeing?

The simplest test is fetal kick count, and that can be done all over the world.

It's just has different descriptions, but the most common one used is 10 fetal movements in two hours.

There have been studies of the reliability of this and really not conclusive, but overall there's felt to be a definite increase in still birth rates in patients who report decreased fetal motion.

Another test that we're gonna be focusing on today is the biophysical profile, and the advantages are that it is non-invasive and there are no contraindications.

Four of the elements of the biophysical profile are an ultrasound, and each parameter of these elements are given zero or two.

The non-stress test is a test done on the labor floor by the labor floor nurse and adds an additional two points to a total of 10 out of 10 for the biophysical profile score.

And a non-stress test, or NST that is reactive is reassuring and has a high negative predictive value along with fetal breathing movement.

Additional tests would be a contraction stress test, and this has been previously used after an abnormal NST but is now less routinely used.

It requires IV administration of oxytocin to contract the uterus and does have some contraindications.

Additionally, fetus can be assessed for fetal growth and doppler velocity Symmetry is also helpful to assess fetal wellbeing in certain patients.

What is the Non-Stress Test?

What is the non-stress test?

The normal baseline heart rate of a fetus is 110 to 160 beats per minute.

And there are normal accelerations in response to fetal movements with the five to 25 beat per minute variability.

And it's just like your heart rate goes up when you exercise.

So when the fetus moves, their heart rate goes up.

A reactive non-stress test is two or more accelerations of at least 15 beats per minute over 15 seconds during the 20 minute exam time.

Non-reactive is less than two accelerations of at least 15 beats per minute, and if it's equivocal can be extended out to 40 minutes.

A non-reactive NST reflects CNS depression due to hypoxia drugs, fetal sleep or congenital abnormalities.

It is most reliable at after 32 weeks to term and before that, for example, between 24 and 28 weeks, 50% may be non-reactive.

So there's a high false positive rate reported as much as 55% or higher.

So question becomes which test to use The biophysical profile or the NST and Dr. Frank Manning has asked if the biophysical profile is normal, do you need the NST?

However, the NST can elicit other findings such as variable decelerations, which may detect cord abnormalities or risk of cord accident.

Development and History of the Biophysical Profile

The biophysical profile was developed in 1980 by Dr. Frank Manning as the main author and Dr. Platt and has been in use for over 30 years.

Over time, there have been minor changes in the amniotic fluid assessment.

It was originally at a stricter depth of one centimeter and subsequently changed to two centimeters.

Other iterations have been proposed over prior decades, such as using a more grade aided scoring system of 0 1 2.

And placental grade or modified biophysical profile is a test that we'll talk about later that is used at some institutions, but in general, close to the original criteria remains what is most commonly used.

Who Performs the Biophysical Profile?

Who performs the biophysical profile?

And I want to state that it can be done in radiology, can be done by maternal fetal medicine, OB doctors or residents may do it, or labor floor nurses.

However, in my opinion, sonographers are the best trained personnel to do an imaging test using ultrasound.

They can be trained to observe the elements of the biophysical profile and image, other findings such as placental abnormalities, cervix, and an overview of the fetus.

And I think what's important is that there's timely physician interpretation as a final interpretation.

So if we have radiologists who are working 24 7, this is an advantage of having radiology perform the biophysical profile.

Operational Success Factors

The operational success factors for success in radiology that we use at our institution is to have a radiology ultrasound room physically located on the labor floor.

Sonographer is assigned on a rotation on the labor floor during the day shift and also during the evening shift to cover the labor floor and OB triage units.

And we also have overnight techs available in the main department.

And as I stated, the 24 7 radiologist is available via PAX communication or immediately by phone to view and interpret images, and the radiologist can scan as needed if they're physically located in that hospital.

Another important factor is the use of dynamic clips on packs to view innings or videos of fetal movements.

What Does the Biophysical Profile Reflect?

What does the biophysical profile reflect?

It reflects amniotic fluid volume as assessment and evaluation of fetal breathing, gross body movements tone, which is comprised of flexion extension movements all within a 30 minute time span and can be added to the NST for a complete score.

Acute parameters affected by fetal acidosis are the NST fetal breathing, gross body movement and tone.

And it's been shown that the biophysical profile score is linearly correlated with fetal pH.

So on the graph to the right, you can see that as the biophysical profile score goes down, the antippartum umbilical Venus pH also is declining.

The non-acute parameter is the amniotic fluid volume, and that is affected by the response to the response of vascular redistribution.

Indications for Biophysical Profile

At our institution, the most common indications are decreased fetal movement, contractions and pain, elevated blood pressure or pregnancy-induced hypertension, preeclampsia, IUGR, ruptured membranes infection, vaginal bleeding, or spotting post dates and MVA and on the right, the ACOG practice bulletin from 2014 also lists maternal conditions such as diabetes and other chronic conditions, hemoglobin, neuropathies, et cetera.

And also there are some pregnancy related conditions as well.

Scoring the Biophysical Profile

How do we score the biophysical profile?

This chart is from perinatology.com and we can see that the fetal breathing movements should be comprised of 30 seconds of adequate breathing within 30 minutes.

Gross body movement requires three or more discrete body or limb movements within 30 minutes.

Fetal tone is one episode of extension or flexion of a fetal extremity or opening and closing of the hand within 30 minutes.

Amniotic fluid volume is defined as a single deepest vertical pocket of amniotic fluid, which measures greater than two centimeters, and the two centimeter pocket should be one centimeter in transverse width before assigning a zero score.

You must observe for 30 minutes.

Of course, there can be exceptions such as severe abruption uterine rupture.

And I would also add that I do not assign a biophysical profile for fetal demise.

I usually will change that to a limited ob, but a demise would not be continued as a biophysical profile.

Fetal Breathing Example

This is an example of fetal breathing.

It's important to look for good rhythmic movement of the chest and ribs or good diaphragmatic movement as shown here in the clip.

And we generally will take several representative serial clips of three second each to show adequate fetal breathing.

We do not clip the entire 30 seconds, but we are sure to demonstrate good representation.

Do not substitute fetal nasal inhalation or exhalation for breathing.

However, hiccups do qualify for fetal breathing.

Fetal Tone Example

There is an example of fetal tone, which is full flexing and extension of the arm leg or opening or closing of a hand.

And we see a hand here opening and closing.

Gross Body Movements

Gross body movements generally is described as truncal movements of the baby.

So we look for three of those within 30 minutes.

Amniotic Fluid Volume Assessment

So now onto the amniotic fluid volume we use for scoring in the dia in the biophysical profile, the single deepest pocket, a two by one centimeter pocket is a greater than two by one centimeter pocket is sufficient.

It is not two by two AT is as is frequently written.

And in communication with Dr. Manning, he stated that this was an aberration of the data and the work of Dr. Everett McGann over 10 years from 2000 to 2011, showed that the single deepest po less than or equal to two centimeters can be compared to the A FI.

And the single deepest pocket yields fewer interventions with similar perinatal outcomes.

And this is the preferred measurement of inadequate fluid.

Both are not considered very accurate compared to amniotic di dilution studies, but commonly used with established norms.

We still use the amniotic fluid index to give an overall assessment of amniotic fluid as shown in the diagram here that we divided into four quadrants and we make sure that we cover each quadrant in our scan.

So the a FI is useful for remote reading to get an overall assessment of the fluid and for serial follow up, and the single deepest pocket can be part of the a FI if it is done accurately.

And it's important to not just measure in the corners, but measure and evaluate the entire quadrant and measure the single deepest pocket in each quadrant.

There is no middle space or dead zone in the middle, so as long as you include the entire quadrant, you can give the deepest part pocket as part of your a FI measurement.

Measurement Technique Tips

Here's some measurement technique tips you should always measure in the longitudinal or sagittal plane.

Your probe should be perpendicular to the floor.

You're going to measure from the anterior uterine wall, and sometimes you can have some near field reverberation.

So you want to exclude the near fear reverberation in your measurement.

You should place the calipers down the center of the pocket to most accurately reflect pocket size and be careful of skinny pockets.

The pocket should be at least one centimeter width.

The radiologist should always review the pockets.

Don't just rely on a number.

Your subjective assessment is very important that you have a feeling for what that fluid amount is subjectively, and it should be consistent with the a FI.

And if it's not, you should redo the entire a FI repeat the four pockets of the measurement and then you should choose the most accurate a FI as far as twins.

Dr. Hill in 2001 described doing a FI of each sack in which you would carefully visualize the sack and measure the four the carefully visualize the membrane and measure the four pockets in each sack versus single deepest pocket in each sack.

Both can yield similar results, but the single deepest pocket method is more accepted nationally.

And this was from the unis driver center.

Uh, NIH PA paper by Dr. Reddy suggested the STP for twins easier to perform, but you still need to show overall the amount of fluid in each sack for twins.

Example of Fluid Measurement

So here's an example of how we measure the fluid.

We put our calipers down in the middle of the pocket as straight as possible, not to the side.

The skinny pockets.

We don't wanna measure necessarily the skinny part, but we wanna get a good representation of the pocket size.

So we generally will measure down the middle and then add them up to a FI of 9.3.

Case Example: Oligohydramnios

Okay, this is a 20-year-old patient who had multiple problems in the pregnancy, preeclampsia, PIH, lower extremity swelling help syndrome, and you could see that the baby was growth restricted at the first percentile.

We measured the fluid pockets, the deepest pocket was 1.8.

So here it is in our a FI, so it is not greater than two.

The total of A A FI was 4.6, which is oligo, and she received zero for fluid, but had the movements breathing and tone present.

The Gradual Hypoxia Concept

What explains the biophysical profile?

The concept is called the gradual hypoxia concept, and spelt that hypoxemia decreases activity in the CNS centers via direct effect with hypoxia, decreasing or depressing cell function, and indirectly due to de diminished perfusion.

Fetal adaptation occurs as the biophysical profiles declines with decrease in oxygen consumption and redistribution of cardiac output in favor of the brain and heart leading to chronic decreased renal profusion and decreased urine output.

There are four different regulatory sensors in the brain that are evaluated by each biophysical profile variable and is thought that those that embryologically developed first are the most resistant to hypoxia.

So for example, fetal movement and tone develop early between about seven to nine weeks and are the most resistant to hypoxia.

And this is shown graphically as we see the brain centers for heart rate acceleration is the medulla.

And as that, so the, this will be affected first with de with the NST.

And then as hypoxia persists, you'll have decreased fetal breathing, which is affected at the ventral surface of the fourth ventricle, and then decrease gross body movements, which is affected at the level of the cortex.

And fetal tone, which is at the subcortical area.

And the maturation of the CNS centers is shown here.

So mo movements in tone are between six to nine weeks, breathing movements, 12 to 14 weeks, the fetal heart rate accelerations for the NST 18 to 20 weeks.

And then we also have development of the sleep weight cycle at 18 to 22 weeks and overall integrated behavioral patterns at 28 weeks.

Gestational Age for Biophysical Profile Testing

What age should we do the biophysical profile?

Technically, you should do it when you can deliver a viable fetus, and generally we use 24 weeks as a general cutoff when we would start the biophysical profile testing if requested, although there are quite a few babies that are less than 24 weeks, such as 21 even, that can survive.

But our typical timing is 24 weeks.

And if we're doing routine TY or typical surveillance in a high risk pregnancy or pregnancy at risk for stillbirth, we would generally start that at 32 weeks and for multiple gestations at 26 to 28 weeks.

Case Example: Low Score at 28 Weeks

So here's a patient who was 28 weeks, two days, came in for decreased fetal movement and had a non-reassuring NST, she received a biophysical profile, zero out of eight.

All parameters were negative.

So we see the clip here, very little fluid.

And really there was no fetal movement at delivery.

She had Apgars of four out of eight, a low pH at 7.2, and the diagnosis was chorioamnioitis.

Predictive Values of the Biophysical Profile

The biophysical profile has is reported to have a low false negative rate as determined by 0.7 deaths per thousand within one week of the test, yielding a negative predictive value of greater than 99%.

And this is the work of Dr. Manning published in 1995.

However, it does have a relatively high false positive rate.

It is less than that of the NST, but can still be significant sometimes up to 40 to 50%.

If you add multiple parameters.

The NSTN and the biophysical profile, this is helpful to reduce the false positive rate.

And from his data, Dr. Manning showed that most biophysical profiles are normal up to 97%, but if you do a lot of them, you're still gonna have some that are normal abnormal.

The mortality increases with the lower score as shown by his data.

ACR Appropriateness Criteria

The a CR appropriateness criteria recently in May of this year came out with a topic on the antenatal testing of fetal wellbeing.

And literature analysis showed that the biophysical profile was not useful for low risk only high risk pregnancies.

So we can see from the rating table that in a low risk pregnancy, these testing only scores two, which is usually not appropriate.

However, in a patient at high risk for adverse fetal outcome, it's scores high and also scores high for preterm pregnancy with abnormal antenatal testing as well as term and post-term pregnancy.

So this is a very useful summary of the data by Dr. Simpson, and it's in the a CR appropriateness criteria.

Data on Perinatal Outcomes

What data do we have about showing that the biophysical profile improves perinatal outcomes?

Well, unfortunately, most of the data are observational studies with which looked at outcomes on older studies and compare them to outcomes after the beginning of antenatal testing in high risk pregnancies.

So the fact that outcomes were improved could be due to multiple factors.

So it's difficult from these studies to say what the exact impact of just doing antenatal testing was and improving outcomes and the high quality randomized controlled trials are lacking.

There was a meta analysis published in 2000 in the Cochrane Review, which looked at four randomized trials, including four studies of two thou of 2,800 women.

But these studies all compared the BPP with something else such as the BPP with the NST or the BPP with the NST and amniotic fluid volume.

And what they found when comparing the BPP with NST, that there was really no significant difference between the groups in perinatal deaths, in infants APGAR scores or overall incidents of C-section.

And it's unlikely that there will be randomized control trials performed due to the wide dissemination of antenatal testing.

Pitfalls of the Biophysical Profile

What are some of the pit falls?

Well, one of the main pitfalls is that the fetus can be in a sleep cycle during the 30 minutes of the testing and the sleep wake cycles on an average 20 minutes, but can be up to 40 minutes in length.

So we try to use maneuvers to wake the fetus from deep sleep.

Generally, you use manual stimulation with the probe, move the mom around, take her off the supine position.

Some advocate the use of VibrAcoustic stimulation, and it's important to consider what outside factors could affect initiation and persistence of the biophysical profiles.

Sedatives such as morphine or stadol, which is a form of morphine, can depress fetal movement.

Patients who receive magnesium sulfate or steroids can be also affected.

Patients who haven't eaten and are hypoglycemic may not do well on the biophysical profile.

So when they come to the OB triage unit or labor floor, the question is should we give them orange juice or something to increase their glucose level?

You could do it, but you should not do it without permission of the nurse or doctor in case there's a C-section needed, or you can give D five IV fluids instead.

For our scheduled routine outpatients, we advise them to eat two hours prior to the biophysical profile.

Factors Affecting the Biophysical Profile

This chart lists some of the factors that affect the biophysical profile.

Fetal sleep, early gestational age, post-term glucose.

If the mother takes eats a lot of sugar may increase fetal breathing.

Alcohol and ingestion can have a depressive effect.

Magnesium ruptured membranes can decrease breathing and fluid and labor can also decrease breathing.

And when we're looking to avoid false positives, we wanna assess the maternal condition.

If there's any underlying problem such as asthma or diabetic ketoacidosis drugs, we should treat those underlying conditions.

Avoiding False Positives

So to avoid false positives, as I mentioned, we should stimulate the fetus, and it's important to get a good clinical history from the physician, communicate with your patient's doctor to find out if this has pregnancy, has had problems, has this been a normal pregnancy?

You want to evaluate the overall appearance.

Does the placenta appear normal?

There's a good amount of amniotic fluid.

You wanna be a little bit skeptical.

And if you suspect a false positive, then it's okay for you as a radiologist to just do a double check beyond the 30 minutes.

You don't wanna do it more than 40 minutes, but you may wanna go back and just verify that you do not see the parameters in the biophysical profile.

And in particular, since the order of the gradual hypoxia concept, usually fetal breathing would be the first movement parameter to be lost.

If you do have fetal breather breathing movement present, but you have a normal NSD and you have a normal NST, but no gross body movement or fetal tone, you have to suspect that perhaps the baby is sleeping and just not moving and you just wanna double check that baby.

If all the movement parameters are absent, there is a higher likelihood that the biophysical profile is abnormal and associated with hypoxemia.

So I think in my mind, is this a floppy baby or not?

When I look at that fetus, so clinical and management what difference does it make?

What you give in the biophysical profile?

Management Based on Biophysical Profile Scores

Well, if you have an eight out of 10, you're missing one parameter and the fluid is normal, you probably are not going to do anything different.

Or you may repeat within 24 hours.

If you have persistent, uncomplicated or isolated oligohydramnios giving you a score, eight outta 10, if the fetus is greater than 36 to 37 weeks, you may wanna consider delivery.

Um, in under the ACOG guidelines, the Society of Canadian gynecologist is slightly different.

If you have two parameters missing, six out of 10, but you have normal fluid, um, in the Canadian, you would repeat.

But in the ACOG guidelines, if it's above 37 weeks, if could consider delivery, if it's less than 37 weeks, you would probably manage the patient and repeat the biophysical profile in 24 hours, four out of 10 delivery is usually indicated at pregnancy, less than 32 weeks manage management should be individualized.

And of course, as you go down lower your, they're going to be prompted to deliver the fetus by such a low score.

Case Example: Term Fetus with Score of 2/8

Here's a term fetus had a biophysical profile.

Two out of eight, they had normal fluid, but no breathing, no movement, no tone.

And at delivery there was meconium stain fluid cord was around the abdomen two times, however, the baby did okay, had good apgars.

So you can see sometimes the maternal breathing can look like breathing, but you really need to look closely at the fetal ribs and diaphragm to see if those are moving.

Case Example: False Positive Due to Sedation

Here's another fetus, 36 weeks and was scored a biophysical two out of eight.

So we questioned the patient and spoke with the doctor and the patient hadn't eaten at all that day, and she was also given stadol at the labor floor for pain.

So the decision was made to give her IV D five fluid and repeat the biophysical profile within about two hours.

And now we see that there's normal movement of the fetal diaphragm and normal fetal breathing.

So she actually scored an eight out of eight.

Case Example: 31 Weeks with Low Score

This is another fetus, 31 weeks, five days with a low biophysical profile score.

And she had sufficient fluid with a with a single deepest pocket of just above two, but had no movement parameters.

They decided to repeat the biophysical profile a few hours later, and we could see the fetal heart rate went down to 57.

And the NST strip was showing D cells, they delivered the patient and the pH was low at 7.2.

The Apgars were eight out of nine, and the baby was later shown to have CNS abnormality absent Calum septum lucidum and poly micro gyre.

Report Elements for Biophysical Profile

The report elements we try to do as complete a report as we can for the biophysical profile test.

We include patient history for our ICD 10 diagnosis, and we document any prior anatomy scans, even if they're done at an outside lab lab, we will document that they were done.

We have to enter in the accurate clinical EDD.

So we may have to say, ask the patient what is your due date?

And they, most of them know, but some of them don't.

Or we obtain the EDD from an early first trimester ultrasound if we have it.

But it's important to try to get an accurate gestational age.

And sometimes we need to call the physician's office, but we need to know what is the accurate dating of that fetus.

And we include in our basic evaluation, fetal presentation, fetal heart rate, placenta location and the amniotic fluid volume, again, as part of the biophysical profile.

In addition, we can add other tests to be ordered with the biophysical profile.

For example, if we want to know the estimated fetal weight and weight percentile, it can be done as an additional OB limited test.

The cervical ultrasound can be requested either as transvaginal, which is the most common, or trans labial if there's a contraindication.

If the patient has not had a complete ob, we would request that we have an order for complete OB ultrasound that could be done along with the bio bi physical profile.

And if there's IUGR, the general recommendation is to do umbilical artery doppler.

We put a disclaimer that fetal anatomy is not included as part of the biophysical profile unless it's ordered.

But we do look at the ventricular chambers when we do the fetal heart rate in the biophysical profile just to exclude that there's a severe anomaly that could have consequence of cyanotic heart disease when the fetus is born.

Case Example: Question of Fetal Breathing

Here's a case where there was question of fetal breathing.

We actually didn't get any other fetal movement.

And now you can see on this clip there is a little bit of movement, but it was not sufficient for the 30 seconds.

We didn't see good sustained rhythmic breathing.

So in this case, I went and scan the fetus, I didn't see the breathing, and she received a zero out of eight.

And the fe the fetus went to C-section.

Repeat Testing

When should we do repeat testing?

Once we've done a biophysical profile?

Well, if the clinical condition that prompted the testing persists, you should do weekly or twice weekly biophysical profile testing until delivery in certain high risk situations, very high blood pressure preeclampsia, you would do two times weekly, or in some cases we have patients who may have un unstable situation of bleeding, but delivery was not indicated.

We may do it daily on some very high risk inpatients, any significant deterioration in fetal activity or an event such as bleeding that requires fetal evalu reevaluation.

The biophysical profile can be repeated regardless of the amount of the time since the last test.

So other independent conditions may cause stillbirth or fetal damage despite being within one week of the normal biophysical profile.

So just because you have the normal biophysical profile doesn't mean other things can occur during that week, where usually the biophysical profile is accurate.

Other Conditions Causing Stillbirth or Fetal Damage

So on the maternal side, you could have placental abruption, antenatal hemorrhage, uterine rupture, different maternal diseases such as diabetic ketoacidosis, sickle cell crisis, cardiovascular event.

You could have drug or alcohol overdose, MVA trauma.

On the fetal side, you have to consider vasa previa, which can lead to catastrophic events if not recognized ruptured membranes or chorioamnioitis cord accidents such as cord prolapse or cord entanglement or not, or umbilical artery thrombosis.

Case Example: Abruption at 33 Weeks

This is a fetus who presented at 33 weeks with preterm contractions and she had a biophysical profile done, which was scored as two out of eight.

However, in this case, there was a question of an abruption.

And you see on the clip here that there was, there's a heterogeneous area at the edge of the placenta, and that was a 40% abruption at delivery.

So if you see an abruption and it's severe enough, there's really no need to continue the biophysical profile if you know that the fetus needs to be delivered.

Modified Biophysical Profile

Okay, just briefly on the modified biophysical profile, it is the non-stress test and a FI only.

And these have the highest positive predictive value for fetal compromise.

Out of all the five parameters, the NST reflects the acute acid-based status.

So if the NST is reactive, it is making an assumption that there is some type of fetal movement and tone.

So this is kind of an abbreviated reflection of that.

The amniotic fluid is volume, is again reflecting the chronic or long-term pl utero placental function.

It is has used a FI in the past with a five centimeter cutoff.

Some people, however, may substitute the single deepest pocket.

It does give a shorter testing time, but has a higher false positive rate, and it does not take into account fetal breathing movement, which is also a high predictor of fetal activity.

And some data has shown that if fetal breathing is absent, it can be as associated with a poor Apgar.

If the modified BPP is abnormal, it is recommended to do a full BPP, and that would be coded as an OB limited study.

Biophysical Profile in Twins

In twins.

We wanna diagnose genicity and amity in each case, and that's important because we have to evaluate the amniotic fluid volume.

And generally we would do the SDP in each sac, and we wanna de demonstrate fluid on each side of the membrane and give overall impression of amniotic fluid in monochorionic mono amniotic monochorionic twins, we would generally report the deepest pocket or a single a FI since there's only one sac.

And sometimes we have come across patients who are diagnosed with oligopoly sacs.

And you have to question is, has there been rupture of one of the sac or leaking, or could it be a twin, twin transfusion?

And we would see that by distinguishing that this only occurs in monochorionic DCO twins and that you would see a growth discrepancy in the fetal sizes.

Case Example: Stuck Twin

So here's a case where we see a large poly sac in this fetus, and then on the second fetus we see the membrane and it's a stuck twin, which is up against the fetal uterine wall with oligo hydrus.

Other Tests: Limited OB, Doppler, Cervix

What other tests would we be doing, as mentioned of limited OB for fetal weight?

In the case of suspected IUGR and also large for gestational H fetus, OB doppler is an additional assessment for fetal wellbeing, but it's not indicated in the average risk pregnancy or indicated in the average.

For gestational H size pregnancy is mainly for IUGR and there are several def different doppler parameters, but mainly we're gonna be using umbilical artery Doppler.

The Society of Maternal Fetal Medicine had stated in 2011 that the MA was considered optional or experimental for IUGR.

So it's not used as commonly today as initially there's additional venous doppler such as the ductus osis Doppler that can show end stage elevation of right atrial pressure.

There's also recently been published a new ratio called CPR, which is cerebral placental ratio, and we'll talk about that later.

Cervical Evaluation

As far as the cervix, I think it's important to make sure that the patient does have a cervical evaluation, particularly if they're contractions or abdominal pain, suspected preterm labor.

And transvaginal ultrasound is of course considered the gold standard, and we will do a three minute, and you could do up to a five minute observation Time to look for dynamic cervix or intermittent funneling trans labial would be an alternative when transvaginal is contraindicated, such as in the case of it's relatively contraindicated in the case of ruptured membranes or if there's an open cervix with bulging membranes is important to know how to do this correctly when you need to do it, because it can be a little more technically difficult.

But I would say both transvaal and trans labial have technical features that you need to observe to get the correct measurement of internal to external os cervical length.

Case Example: Cervical Evaluation with Cord

So here is a patient who came, we had a cervical evaluation.

This is just a clip from right to left, and you can kind of see where the endocervical canal is.

And this is a curved cervix, but we also see the cord here.

So our objective is the cord in the membrane or is this free cord?

And here this is free cord.

This is presenting cord at risk for cord prolapse if the patient goes into labor.

So it's important to note that, but you see that the cord is it can be moved away from the membrane.

And so it's not a VAs previa.

Case Example: Cord Prolapse

And here is an older case of cord prolapse.

So as the patient ruptures the membrane, the cord can prolapse into the cervix and can be compressed and cause an adverse fetal outcome.

Case Example: Vasa Previa

Here is a case of vasia previa where the cord is implanted is within the membrane.

It's known as veis cord insertion.

So if you do not see placental cord insertion in the placenta, but it's in the membrane and overlies the cervix, this is extremely important to note and inform your OB physician and will alter how management in terms of having a safe delivery.

And you wanna make sure that you have fetal heart rate and fetal uh vessels here within the membrane.

The other possibility is that you have a urate lobe, and this could be an interconnecting vessel between the placenta and the URT lobe, but it still contains fetal vessels.

And if the cervix dilates, then the fetus would be at risk for exsanguination.

Fetal Presentation

Also, when we give our above physical profile report, we wanna make sure we give the a correct fetal presentation so that if they need to deliver the patient, they know what they're dealing with.

And this was an interesting case we had recently where it appeared at one point that there was a cephalic presentation.

However, as you clip through the cervix, you see that there's also the fetal legs presenting and there's actually some fetal cord here.

So this position with both the head and the legs presenting is called compound presentation.

And also the core presenting is also known as IC presentation.

Case Example: Severe IUGR at 37 Weeks

Here's a case of severe IUGR 37 weeks.

She had a biophysical profile four out of eight with no fetal breathing, and RUP was ruptured with the single deepest pocket less than two centimeters.

Here we see it's 1.8 and we see that this is well below the 10th percentile for weight.

So this would be a case for umbilical artery doppler.

Umbilical Artery Doppler

And the primary indication, as I mentioned, is IUGR below the 10th percentile.

And it reflects utero placental insufficiency.

It is not useful for the average gestational H fetus.

And it's important to note according to Dr. Baha's article from 2001, that abnormal umbilical artery doppler is the earliest sign of fetal compromise, followed by abnormal venous waveforms and then the abnormal biophysical profile after that.

In the measurement, we use the systolic to diastolic ratio and also the pulsatility index.

Um, technical tips.

We do three samples in the mid cord when the fetus is relatively quiescent, and we try to take the cord with the doppler angle zero, so the cord is more straight up and down for the best results.

Case Example: Reversed End Diastolic Flow

So here is the fetus, and we did the MCA doppler.

This, we did the umbilical artery doppler here on top and the MCA doppler on below.

So we're showing that there's reversed end diastolic flow.

So an umbilical red doppler we're looking for absent or reversed end diastolic flow, which is the most worrisome.

And we see that doesn't can't really calculate an SD because it goes below zero, but we also have an elevated pulsatility of index of 2.19.

The MCA Doppler shows the SD ratio is less than four.

So this is abnormal.

And this patient also had a placental cyst.

So so is a patient with severe IUGR.

Management of Abnormal Doppler

And what is the management of these patients?

So it is has been shown that normal umbilical artery doppler is associated with lower risk for fetal acidemia and perinatal death within high risk pregnancies.

Fetal growth restriction guidelines from the Society for Maternal Fetal ME medicine recommend if there's absent end diastolic flow deliver at greater than 37, greater than 34 weeks.

And if there's reversed end diastolic flow deliver above 32 weeks.

Cerebral Placental Ratio (CPR)

And this is the cerebral placental ratio.

This is the patient we showed earlier.

So you're gonna take a ratio of the MCA to the umbilical artery, and this was first published by Dr. ODI BO in 2005, and you're going to compare the pulsatility indices.

So if the ratio of the MCA to umbilical artery is greater than approximately one to one, that's considered normal.

And if less than one to one is abnormal.

So it's kind of it's combining these two measurements.

Um, a placental resistance and also the vascular redistribution in the MCA.

So this is less than one in this fetus, and it would be considered to be associated with adverse perinatal outcome.

In an article read recently published by Dr. Devore, it's also has suggestion that it also be used in average for gestational age fetuses.

And this was also published by Dr. Khalil that it was an independent predictor of the need for operative delivery.

Coding

As far as coding, we use seven, the 7 6 8 1 9 for the biophysical profile without the NST and the NST can be coded separately by the OB department.

And these are our OB cards codes that we would use for the additional testing.

Summary

So in summary, think that biophysical profile can be offered with good quality and response time.

In the current 24 7 radiology departments, we can give a physician final report.

We must be decisive and communicate our results to facilitate prompt delivery when needed.

And I think that we can add value to our institutions in participating in this and being part of a multidisciplinary OB care team.

And the use of the biophysical profile in the high risk patient is associated with significant reduction in perinatal mortality.

Thank you for attending.