Category: Patient Guide

One question parents sometimes ask while looking at their baby’s 3D ultrasound is:

“Does my baby already have double eyelids?”

When a baby’s face is captured clearly, you may notice a small crease above the eye that looks surprisingly similar to a double-eyelid fold.

But can a 3D or 4D ultrasound really tell whether a baby will have double eyelids after birth?

Can eyelids be seen on a 3D ultrasound?

Yes, sometimes.

3D ultrasound reconstructs the surface of the baby’s face, allowing parents to see facial contours such as the nose, lips, cheeks, chin, and eyelids.

When the baby is facing the ultrasound probe and there is enough amniotic fluid around the face, the eyelid contours may appear quite clearly.

In some images, a small line or fold can appear above the eye.

This may look very much like a double-eyelid crease.

Does that mean the baby will have double eyelids after birth?

Not necessarily.

A 3D ultrasound image is not the same as a photograph. The ultrasound machine collects sound-wave information and reconstructs it into a three-dimensional surface image.

Because of this, small facial details can look different depending on several factors, including:

• the baby’s position
• the angle of the ultrasound
• the amount of amniotic fluid in front of the face
• the baby’s proximity to the placenta or uterine wall
• image rendering and ultrasound settings

A line that looks like a double-eyelid crease may therefore appear in one image and disappear in another.

So even when a clear crease is visible on a 3D ultrasound, it cannot reliably predict whether the baby will have double eyelids after birth.

Why did I see a crease during one ultrasound but not another?

This is completely possible.

The quality and appearance of a 3D ultrasound image can change significantly depending on the baby’s position.

If there is a good pocket of amniotic fluid in front of the face, the facial surface can be reconstructed more clearly.

But if the baby’s face is pressed against the placenta or uterine wall, small details around the eyes may become distorted or disappear.

Even a slight change in angle can make the eyelids look different.

That’s why two 3D ultrasound images of the same baby can sometimes look surprisingly different.

How much can 3D ultrasound tell us about a baby’s face?

When conditions are favorable, 3D ultrasound can provide an impressive view of the baby’s overall facial appearance.

You may be able to recognize the shape of the:

nose, lips, cheeks, chin, and general facial contour.

However, very fine skin details—such as a permanent eyelid crease—are much more difficult to predict accurately.

The baby’s appearance will also continue to change during pregnancy and after birth.

A sonographer’s tip

If you notice what looks like a tiny double-eyelid crease on your baby’s ultrasound, enjoy the moment—but think of it as a cute observation rather than a prediction.

Instead of saying,

“My baby definitely has double eyelids!”

it may be more accurate to say,

“It looks like there might be a little eyelid crease in this image.”

One of the most enjoyable things about 3D ultrasound is looking back at those images after your baby is born and comparing them with your baby’s real face.

Sometimes the resemblance is surprisingly strong.

So, can you see double eyelids on a 3D ultrasound?

A double-eyelid-like crease can sometimes be visible on a 3D or 4D ultrasound, but it cannot reliably confirm whether the baby will actually have double eyelids after birth.

Think of it as one more adorable detail you may happen to catch during your baby’s ultrasound—not a definite prediction of what their eyes will look like.

If your baby has been diagnosed with Fetal Growth Restriction (FGR), previously commonly called IUGR, you may wonder:

“Will my baby always be small after birth?”

Not necessarily.

Many babies who were small during pregnancy may show catch-up growth after birth.

What Is Catch-Up Growth?

Catch-up growth means that a baby who was small at birth grows faster than expected for a period of time and gradually reduces the size difference compared with other children of the same age.

Inside the uterus, fetal growth may have been affected by placental function or other pregnancy-related factors.

After birth, the baby’s environment changes and nutrition is provided directly, which may support improved growth.

Do All FGR Babies Show Catch-Up Growth?

No.

Every baby follows a different growth pattern.

Postnatal growth may be influenced by:

• Gestational age at birth
• Birth weight
• Severity of fetal growth restriction
• Cause of FGR
• Genetic body size
• Nutrition after birth
• Overall health

This is why it is more useful to follow the baby’s individual growth curve than to compare the baby with others.

Is Weight the Only Thing That Matters?

No.

After birth, healthcare providers usually monitor:

• Weight
• Length or height
• Head circumference

A single measurement is less important than the pattern of growth over time.

Just as serial ultrasound measurements are useful during pregnancy, repeated growth measurements after birth help show whether the baby is progressing steadily.

When Does Catch-Up Growth Happen?

The timing of catch-up growth varies.

Some babies begin gaining rapidly soon after birth, while others follow a slower and steadier pattern.

There is no single timeline that applies to every baby.

Regular pediatric checkups help healthcare providers assess whether growth is progressing appropriately.

Is Faster Weight Gain Always Better?

Not necessarily.

A baby who was small at birth does not always need to gain weight as quickly as possible.

The goal is healthy, appropriate growth, not simply rapid weight gain.

Nutrition and growth should be monitored according to the baby’s individual needs and overall health.

What Should Parents Focus On?

Instead of asking only:

“How much does my baby weigh?”

it can be more helpful to ask:

“Is my baby continuing to grow?”

“Are weight, length, and head circumference progressing along a healthy curve?”

Growth over time provides much more information than one number alone.

The Key Message

FGR does not mean that a child will always remain small.

Many babies show some degree of catch-up growth after birth.

What matters most is the overall growth pattern, including weight, length, and head circumference, along with the baby’s health and development.

Regular follow-up with your pediatric healthcare provider helps ensure that growth is monitored appropriately.

This article is for general pregnancy and infant growth education only and is not a substitute for individualized medical advice, diagnosis, or treatment.

If your baby is suspected of having Fetal Growth Restriction (FGR), previously commonly called IUGR, you may be scheduled for additional ultrasound examinations.

Many parents wonder:

“What are they checking every time I have another ultrasound?”

Follow-up ultrasound for FGR is about much more than checking how many grams your baby has gained.

Healthcare providers assess fetal growth, amniotic fluid, placental circulation, and fetal well-being together.

1. Estimated Fetal Weight (EFW)

One of the first things evaluated is the baby’s Estimated Fetal Weight (EFW).

Measurements of different parts of the fetal body are used to estimate the baby’s weight and determine where it falls on a growth chart for the current gestational age.

However, EFW is an estimate, not an exact measurement of fetal weight.

This is why healthcare providers do not rely on one EFW result alone.

2. Abdominal Circumference (AC)

Abdominal Circumference (AC) is particularly important when fetal growth restriction is suspected.

Placental insufficiency can affect fetal abdominal growth, so healthcare providers assess both the current AC measurement and how it changes over time.

A relatively small AC may be one of the findings that prompts closer evaluation of fetal growth.

3. Growth Trend

One of the most important reasons for performing follow-up ultrasounds is to evaluate the baby’s growth over time.

A baby may be small but continue growing along a relatively consistent pattern.

In other cases, measurements may progressively fall across percentiles or growth may slow.

This is why serial ultrasound examinations can provide more useful information than focusing on one measurement alone.

4. Amniotic Fluid

Amniotic fluid is another important part of FGR monitoring.

When placental function becomes significantly impaired, fetal kidney blood flow and urine production may decrease.

This can sometimes lead to reduced amniotic fluid.

Healthcare providers therefore assess amniotic fluid along with fetal growth and other findings.

5. Umbilical Artery Doppler

Umbilical Artery Doppler provides information about resistance in the placental circulation.

Healthcare providers assess the blood-flow pattern and look for changes that may suggest increasing placental resistance.

In more severe cases, abnormalities in end-diastolic blood flow can occur and may affect how closely the pregnancy needs to be monitored.

6. MCA Doppler and CPR

In some pregnancies, the Middle Cerebral Artery (MCA) is also evaluated.

Changes in MCA blood flow can provide information about how the fetus may be adapting to its environment.

Healthcare providers may also calculate the Cerebroplacental Ratio (CPR), which compares aspects of cerebral and placental circulation.

These Doppler findings are interpreted together with fetal size, growth trend, gestational age and the overall clinical picture.

7. Overall Fetal Well-Being

Ultimately, FGR monitoring is not about one number.

Healthcare providers want to understand:

Is the baby continuing to grow?

Is the amniotic fluid reassuring?

Is placental and fetal blood flow stable?

Does the baby appear to be doing well inside the uterus?

Other fetal surveillance and the mother’s health may also be considered when deciding how closely the pregnancy should be monitored and when delivery may be appropriate.

The Key Message

An FGR follow-up ultrasound is much more than a “baby weight check.”

Healthcare providers look at:

EFW + AC + Growth Trend + Amniotic Fluid + Doppler Blood Flow

Together, these findings provide a more complete picture of how the baby is growing and coping inside the uterus.

If your baby is measuring small, try not to focus on a single weight or percentile alone.

The pattern over time and the overall fetal assessment are what matter most.

This article is for general pregnancy and ultrasound education only and is not a substitute for individualized medical advice, diagnosis, or treatment.

One of the most common questions parents ask during a 3D ultrasound is:

“Is getting a clear 3D ultrasound picture just a matter of luck?”

Some babies show their faces beautifully as soon as the ultrasound begins. Others turn away, cover their faces with their hands, or stay in the same position throughout the entire exam.

So why do some 3D ultrasound images look incredibly clear while others don’t?

The short answer is: there is a little bit of luck involved, but several physical factors matter much more.

1. Your Baby’s Position Matters Most

One of the biggest factors is the direction your baby is facing.

If the baby’s face is positioned toward an area that can be easily reached by the ultrasound beam, it may be easier to obtain a clear image.

However, if the baby is facing toward the mother’s back or pressing the face against the uterine wall, getting a full facial image can be difficult.

Sometimes even an experienced sonographer simply has to wait for the baby to change position.

2. Amniotic Fluid in Front of the Face Helps

For a clear 3D ultrasound image, having some fluid-filled space in front of the baby’s face is very helpful.

When there is adequate amniotic fluid between the face and surrounding structures, features such as the forehead, nose, lips, and cheeks can often be displayed more clearly.

If the baby’s face is pressed directly against the placenta or uterine wall, parts of the face may appear distorted or may not be reconstructed clearly.

It is not only the overall amount of amniotic fluid that matters.

The space directly in front of the baby’s face is especially important.

3. Placental Location Can Affect the Image

Having an anterior placenta does not automatically mean that you cannot get a good 3D ultrasound image.

What matters more is the relationship between the baby’s face and the placenta.

If the baby is pressing the face directly against the placenta, there may not be enough fluid-filled space to clearly display the facial surface.

On the other hand, a good image may still be possible when there is adequate space in front of the face.

4. Hands, Feet, or the Umbilical Cord May Get in the Way

Babies frequently place their hands near their faces.

Sometimes both hands cover the face. A foot may even appear near the face depending on the baby’s position.

The umbilical cord can also pass in front of the face.

These structures may partially obscure the facial features on a 3D ultrasound.

Sometimes waiting a little, changing the mother’s position, or allowing the baby some time to move can improve the view.

5. Gestational Age Makes a Difference

Earlier in pregnancy, the baby has less fat beneath the skin, so the face may look thinner than the familiar chubby newborn appearance.

As pregnancy progresses, the cheeks and facial features often become fuller.

However, later in pregnancy the baby also becomes larger and has less room to move.

This can make it more difficult to create enough space in front of the face.

So later does not always mean better when it comes to 3D ultrasound images.

6. Sometimes Timing Really Is Luck

This is where luck comes into the picture.

A baby who is covering the face at the beginning of the examination may suddenly move a hand away or turn the head.

Another baby may remain in exactly the same position throughout the entire scan.

That is why sonographers may ask the mother to change position, move around briefly, or wait before trying again.

Sometimes the perfect 3D image really does depend on what the baby decides to do at that particular moment.

Does a Poor 3D Ultrasound Image Mean Something Is Wrong?

No.

Not getting a clear 3D picture of your baby’s face does not by itself mean that there is a problem with the baby.

The most common reasons are simply fetal position, limited space in front of the face, or a hand, foot, placenta, or umbilical cord blocking the view.

A diagnostic ultrasound examination and obtaining a beautiful keepsake-style 3D facial image are also not the same thing.

The clarity of a 3D facial picture should therefore not be used as a measure of your baby’s health.

So, Is a Good 3D Ultrasound Picture Just Luck?

A little—but mostly it depends on the conditions at the time of the scan.

Your baby’s position, the amount of fluid-filled space in front of the face, nearby placenta, hands or umbilical cord, gestational age, and movement can all affect the final image.

Sometimes a baby shows the entire face immediately.

Other times, those tiny hands stay firmly over the face for the whole examination.

Either way, the quality of a 3D ultrasound photo does not determine how healthy your baby is.

This article is for general educational purposes and does not replace medical advice or a diagnostic ultrasound examination.

If your baby has been diagnosed with or is being monitored for Fetal Growth Restriction (FGR), one of the first questions you may have is:

“Will my baby need to be delivered early?”

FGR, previously commonly called IUGR (Intrauterine Growth Restriction), does not automatically mean that your baby needs immediate or premature delivery.

The decision depends on much more than the baby’s size alone.

Does FGR Always Mean Early Delivery?

No.

Some babies with FGR continue to grow steadily and have reassuring Doppler blood flow, amniotic fluid, and fetal monitoring.

In these situations, healthcare providers may continue the pregnancy with regular surveillance.

However, if fetal growth slows significantly or there are concerning changes in placental blood flow or fetal well-being, closer monitoring or earlier delivery may be recommended.

What Determines Delivery Timing in FGR?

Healthcare providers consider several factors together, including:

• Gestational age
• Estimated Fetal Weight (EFW)
• Fetal growth percentile
• Abdominal Circumference (AC)
• Growth compared with previous ultrasounds
• Amniotic fluid volume
• Umbilical Artery Doppler
• MCA Doppler and CPR when appropriate
• Overall fetal well-being
• Maternal health and blood pressure

This means delivery timing is not based on one ultrasound measurement alone.

The whole clinical picture matters.

Why Not Deliver the Baby Immediately?

If placental function is reduced, it may seem safer to deliver the baby as soon as possible.

But when FGR develops earlier in pregnancy, doctors must also consider the risks associated with premature birth.

The goal is therefore to balance two important questions:

Is it safer for the baby to remain in the uterus?

or

Has delivery become the safer option?

This balance can change as pregnancy progresses.

Why Is Umbilical Artery Doppler Important?

Umbilical Artery Doppler provides important information about resistance in the placental circulation.

Healthcare providers assess the blood-flow pattern and whether end-diastolic flow remains present.

More significant Doppler abnormalities may indicate greater placental dysfunction and can influence how closely the pregnancy is monitored and when delivery should be considered.

This is why fetal weight percentile alone does not determine delivery timing.

What If My Baby Is Small but Still Growing?

Growth over time is very important.

A baby may be small but continue to show measurable growth between ultrasound examinations.

If growth continues and other assessments remain reassuring, this information may support ongoing monitoring rather than immediate delivery.

This is one reason serial growth ultrasounds are so useful in pregnancies affected by suspected FGR.

Is There One Recommended Week for Delivery?

There is no single delivery week that applies to every pregnancy with FGR.

The appropriate timing depends on the severity of growth restriction, gestational age, Doppler findings, fetal surveillance, maternal health, and other pregnancy-specific factors.

Some pregnancies can safely continue closer to term, while others may require earlier delivery.

Your healthcare team will determine the safest timing based on your individual situation.

The Key Message

When deciding when to deliver a baby with FGR, the most important question is not simply:

“How small is the baby?”

Healthcare providers also consider:

“Is the baby continuing to grow?”

“Is placental blood flow reassuring?”

“Is the baby doing well inside the uterus?”

“Is continuing the pregnancy safer than delivery?”

FGR does not automatically mean immediate delivery.

Regular growth scans, Doppler ultrasound, fetal surveillance, and maternal assessment help healthcare providers determine the safest time for birth.

This article is for general pregnancy and ultrasound education only. Delivery timing for FGR should always be determined by your obstetric healthcare team based on your individual pregnancy.

Hearing that your baby is “measuring small” on ultrasound can be worrying.

You may be told that your baby’s estimated weight is below the 10th percentile and immediately wonder:

Does this mean my baby has IUGR?

Not necessarily.

A baby who is small for gestational age and a baby whose growth is truly restricted are not always the same thing.

Here is the difference between SGA (Small for Gestational Age) and FGR (Fetal Growth Restriction), previously commonly called IUGR.

What Is SGA?

SGA stands for Small for Gestational Age.

It generally describes a fetus whose estimated size or weight is small for the current gestational age, commonly below the 10th percentile.

But being small does not automatically mean that something is wrong.

Some babies are naturally small because of genetics or parental body size.

These babies may remain small throughout pregnancy while continuing to grow steadily. Their amniotic fluid and Doppler blood flow may also remain normal.

What Is FGR or IUGR?

FGR stands for Fetal Growth Restriction.

You may also hear the older term IUGR (Intrauterine Growth Restriction).

FGR means that the fetus may not be reaching its expected growth potential.

One important cause is placental insufficiency, in which the placenta may not provide the fetus with enough oxygen and nutrients to support optimal growth.

This is why doctors look at much more than fetal weight alone.

SGA vs FGR: What Is the Difference?

An easy way to understand the difference is:

SGA = The baby is small.

FGR = The baby’s growth may be restricted.

A fetus can be small and healthy.

On the other hand, fetal growth restriction is concerned not only with size, but also with how the baby is growing over time and whether there are signs of placental dysfunction.

How Does Ultrasound Help?

When a baby is measuring small, ultrasound assessment may include:

• Estimated Fetal Weight (EFW)
• Abdominal Circumference (AC)
• Head Circumference (HC)
• Femur Length (FL)
• Growth compared with previous examinations
• Amniotic fluid volume
• Placental assessment
• Umbilical Artery Doppler
• Middle Cerebral Artery (MCA) Doppler
• Cerebroplacental Ratio (CPR), when indicated

These findings help healthcare providers determine whether the baby is simply small or whether closer monitoring for fetal growth restriction is needed.

Why Is Abdominal Circumference Important?

Abdominal Circumference, or AC, is an important measurement when assessing fetal growth.

When placental function is impaired, fetal abdominal growth may be affected.

In some growth-restricted babies, the abdomen may therefore appear relatively smaller compared with other fetal measurements.

However, AC should never be interpreted in isolation. The overall growth pattern, fetal weight, Doppler findings and clinical situation all need to be considered together.

Does Below the 10th Percentile Always Mean Something Is Wrong?

No.

Being below the 10th percentile does not automatically mean that a baby is unhealthy.

Some babies are constitutionally small and continue to grow normally.

This is why the pattern of growth over time can be just as important as a single estimated fetal weight measurement.

Serial growth ultrasounds can help show whether the baby continues to grow along an expected pattern or whether growth is slowing.

What Happens If My Baby Is Measuring Small?

If your baby is measuring small, your healthcare provider may recommend additional growth ultrasounds and, when appropriate, Doppler studies.

The goal is not simply to determine how many grams the baby weighs.

The more important questions are:

Is the baby continuing to grow?

Is the placenta supporting the baby adequately?

Is the blood flow reassuring?

A small baby is not always a growth-restricted baby.

Regular monitoring helps healthcare providers distinguish between a healthy, naturally small fetus and a fetus that may require closer surveillance.

This article is for general pregnancy and ultrasound education and is not a substitute for individualized medical advice, diagnosis or treatment.

Wondering if your baby’s weight is normal? Learn the average fetal weight by week from 12 to 40 weeks, how ultrasound estimates fetal weight (EFW), and what normal growth looks like during pregnancy.
Fetal Weight by Week: Is My Baby Growing Normally?

One of the most common questions during pregnancy is:

“Is my baby’s weight normal?”

During routine prenatal ultrasounds, doctors estimate your baby’s weight using several body measurements. This estimate is called Estimated Fetal Weight (EFW).

The table below shows the approximate average fetal weight throughout pregnancy.

Average Fetal Weight by Week

Gestational Age	Average Weight
12 weeks	14 g
16 weeks	100 g
20 weeks	300 g
24 weeks	600 g
28 weeks	1,100 g
30 weeks	1,400 g
32 weeks	1,700 g
34 weeks	2,200 g
36 weeks	2,700 g
38 weeks	3,100 g
40 weeks	3,300~3,500 g

These values are averages. Every baby grows at a slightly different rate.

How Is Fetal Weight Estimated?

Ultrasound does not measure your baby’s weight directly.

Instead, it calculates an estimate using several fetal measurements, including:

• Biparietal Diameter (BPD)
• Head Circumference (HC)
• Abdominal Circumference (AC)
• Femur Length (FL)

These measurements are entered into validated formulas to calculate the Estimated Fetal Weight (EFW).

How Accurate Is Ultrasound Weight Estimation?

Many parents ask,

“Can ultrasound accurately predict my baby’s weight?”

The answer is mostly yes—but not perfectly.

Ultrasound estimates usually have an error range of ±10–15%.

For example, if the estimated weight is 2,000 g, the actual birth weight may reasonably range from about 1,700 to 2,300 g.

For this reason, healthcare providers focus more on your baby’s growth trend over time than on a single measurement.

What If My Baby Is Smaller Than Average?

A smaller-than-average baby is not always a cause for concern.

Possible reasons include:

• Family genetics
• Naturally small body size
• Normal variation in fetal growth

However, if growth slows significantly or blood flow abnormalities are detected, your doctor may evaluate for Fetal Growth Restriction (FGR/IUGR).

What If My Baby Is Larger Than Average?

A larger baby can also be completely healthy.

Sometimes, increased fetal weight may be associated with:

• Gestational diabetes
• Large for Gestational Age (LGA)
• Delivery planning considerations

Your healthcare provider will assess the overall clinical picture rather than fetal weight alone.

Frequently Asked Questions

Is 1 kg normal at 28 weeks?

Yes. Around 1,100 g is considered average at 28 weeks, so approximately 1 kg is often within the normal range depending on individual growth patterns.

My baby measures two weeks behind. Should I worry?

Not necessarily.

Doctors usually monitor growth over time rather than relying on a single ultrasound measurement.

Is ultrasound weight the same as birth weight?

No.

Estimated Fetal Weight (EFW) is an approximation and may differ from the baby’s actual birth weight.

Final Thoughts

Fetal weight is an important indicator of your baby’s development, but it is only one part of the overall assessment.

Doctors also evaluate fetal anatomy, amniotic fluid, placental function, blood flow, and the baby’s growth pattern over time.

Regular prenatal care and follow-up ultrasounds are the best ways to monitor your baby’s health.

Many expectant parents become nervous when the sonographer gently jiggles or taps the mother’s abdomen during a 3D ultrasound.

One of the most common questions is:

“Is my baby okay?”
“Does shaking my belly hurt the baby?”

The good news is that this gentle movement is a normal part of many 3D ultrasound examinations and is generally considered safe when performed by a trained healthcare professional.

Why Do We Gently Shake the Belly?

A 3D ultrasound depends on the baby’s position.

Sometimes the baby’s face is hidden because they are:

• Facing the placenta
• Resting against the uterine wall
• Covering their face with their hands or feet
• Sleeping in the same position

When this happens, the sonographer may gently jiggle the mother’s abdomen to encourage the baby to move just enough for a clearer view.

The goal is not to force the baby to move, but simply to create a small change in position.

How Much Movement Does the Baby Feel?

Many parents imagine that the baby is being shaken strongly.

In reality, the movement is usually very gentle.

I often explain it this way to my patients:

It is similar to the movement your baby experiences when you walk or climb a few stairs.

Babies naturally experience movement throughout pregnancy whenever the mother:

• Walks
• Changes position
• Rides in a car
• Goes about her normal daily activities

A gentle abdominal jiggle during a 3D ultrasound is generally no more intense than these everyday movements.

What If the Baby Still Doesn’t Move?

Some babies simply love to sleep.

Even after gentle stimulation, they may continue covering their face or remain in the same position.

In those situations, the sonographer may:

• Wait a few minutes
• Ask the mother to walk around briefly
• Change the mother’s position
• Schedule another attempt if needed

We do not keep shaking harder just to get a better picture.

Safety Always Comes First

Although parents enjoy seeing their baby’s face, the baby’s well-being is always the top priority.

A clear 3D image is wonderful, but it is never worth making the mother uncomfortable or using excessive pressure.

Every examination is performed with safety in mind.

Final Thoughts

If your sonographer gently shakes your belly during a 3D ultrasound, there’s usually no reason to worry.

In many cases, it’s simply a gentle technique to help your baby turn their face toward the ultrasound probe.

Sometimes it works.

Sometimes your little one decides to keep sleeping anyway—and that’s perfectly normal too.

If you are expecting identical twins who share one placenta, you may have heard of Twin-to-Twin Transfusion Syndrome (TTTS). This condition can sound frightening, but regular detailed ultrasound examinations allow specialists to detect it early and monitor your babies closely.

So, what exactly do sonographers look for during a detailed ultrasound?

What Is TTTS?

Twin-to-Twin Transfusion Syndrome (TTTS) is a complication that occurs only in monochorionic twin pregnancies, where both babies share a single placenta.

Tiny blood vessel connections within the placenta can cause blood to flow unevenly between the twins. As a result:

• The donor twin loses blood volume.
• The recipient twin receives too much blood.

Without treatment, TTTS can affect the health of both babies.

1. Confirming Chorionicity

The first step is determining whether the twins share one placenta.

TTTS develops only in monochorionic twins, making chorionicity the most important starting point of the examination.

2. Measuring Amniotic Fluid

One of the key ultrasound findings is the difference in amniotic fluid around each baby.

The sonographer measures the Deepest Vertical Pocket (DVP) for both twins.

Typical findings include:

• Donor twin: Very little amniotic fluid (oligohydramnios)
• Recipient twin: Excess amniotic fluid (polyhydramnios)

This imbalance is often the earliest sign of TTTS.

3. Evaluating the Bladder

The babies’ bladders provide important clues.

The donor twin may produce very little urine, causing the bladder to appear very small or even invisible during the examination.

The recipient twin often has a larger, well-filled bladder because increased blood flow leads to increased urine production.

4. Comparing Fetal Growth

Measurements are obtained for both babies, including:

• Biparietal Diameter (BPD)
• Head Circumference (HC)
• Abdominal Circumference (AC)
• Femur Length (FL)
• Estimated Fetal Weight (EFW)

Although growth differences do not confirm TTTS by themselves, they help distinguish TTTS from other complications such as selective fetal growth restriction (sFGR).

5. Performing Doppler Ultrasound

Blood flow is carefully assessed using Doppler ultrasound.

The following vessels are commonly evaluated:

• Umbilical Artery (UA)
• Middle Cerebral Artery (MCA)
• Ductus Venosus (DV)
• Umbilical Vein (UV)

Abnormal Doppler findings may indicate that TTTS has progressed and requires urgent evaluation.

6. Examining the Heart

The recipient twin’s heart works harder because of increased blood volume.

During the ultrasound, specialists evaluate:

• Heart size
• Cardiac function
• Valve regurgitation
• Signs of heart strain

Early detection of cardiac changes is essential for treatment planning.

7. Looking for Hydrops Fetalis

In severe cases, fluid may accumulate in different parts of the baby’s body.

The sonographer checks for:

• Ascites
• Pleural effusion
• Pericardial effusion
• Skin edema

These findings suggest advanced disease and require immediate medical attention.

What Is the Usual Ultrasound Checklist?

During a detailed ultrasound, specialists generally assess:

• Placental sharing (chorionicity)
• Amniotic fluid volume
• Fetal bladder
• Fetal growth
• Doppler blood flow
• Cardiac function
• Hydrops fetalis

Each step provides important information about the health of both babies.

Final Thoughts

TTTS is a serious but treatable complication when detected early.

Regular ultrasound surveillance is essential for monochorionic twin pregnancies because changes in amniotic fluid, blood flow, and fetal heart function may develop over time.

A detailed ultrasound is much more than simply seeing your babies’ faces—it is a comprehensive examination that helps protect both twins throughout pregnancy.

One of the most common questions sonographers hear during the anatomy scan is:

“Will we be able to see our baby’s face today?”

For healthcare professionals, the anatomy scan is a detailed medical examination. We carefully assess the baby’s brain, heart, spine, kidneys, limbs, and many other organs to ensure healthy development.

For parents, however, this appointment often means something much more personal.

It is the day they hope to truly “meet” their baby.

Seeing the Face Makes the Baby Feel Real

Although parents may have already felt kicks and seen previous ultrasound images, the baby’s face creates a completely different emotional connection.

Watching a baby yawn, suck a thumb, or make tiny facial expressions reminds parents that there is a little person growing inside the womb.

For many families, this is the moment pregnancy becomes even more real.

It Brings Comfort and Reassurance

Parents naturally want to know that their baby is growing well.

While sonographers evaluate the facial anatomy for medical reasons, many parents simply feel reassured when they can see their baby’s face.

Sometimes, just one clear image is enough to ease weeks of anxiety.

Everyone Starts Guessing the Family Resemblance

“She has Mom’s lips.”

“He looks just like Dad.”

These conversations often begin long before birth.

A single ultrasound image can spark excitement and strengthen the emotional bond between parents and their unborn baby.

Why Can’t We Always See the Baby’s Face?

This is probably the biggest disappointment for many parents.

The truth is that babies don’t always cooperate.

Your baby may be:

• Facing the mother’s back
• Covering the face with tiny hands
• Hidden behind the placenta or umbilical cord
• In a position that makes facial imaging difficult

The amount of amniotic fluid, gestational age, and maternal body habitus can also affect image quality.

Not seeing the face does not usually mean that something is wrong.

Sonographers Feel the Pressure Too

Many parents don’t realize that sonographers also hope to capture a beautiful face.

We know how much families are looking forward to that special moment.

But our first responsibility is to perform a thorough medical examination.

Sometimes we spend more time examining the baby’s heart or brain than trying to obtain the perfect facial image.

A healthy baby is always more important than the perfect ultrasound picture.

A Message for Expecting Parents

If your baby’s face wasn’t visible during today’s scan, don’t be discouraged.

Babies often change positions, and what wasn’t possible today may be easy at the next visit.

The most important result of an anatomy scan is not a perfect photo.

It’s the reassuring news that your baby is growing healthy and developing well.

Before long, you’ll see your baby’s face—not on an ultrasound screen, but in your arms.