Pregnancy is an exciting journey filled with several important milestones. Among all prenatal investigations, the Anomaly Scan, also known as the Level II Ultrasound, is considered one of the most significant. It provides a detailed assessment of your baby’s growth, anatomy, and development while helping identify many structural abnormalities before birth.

For many parents, this scan is reassuring because it confirms that their baby is developing normally. In some cases, it helps doctors detect conditions early so that proper planning, treatment, or specialized care can be arranged before delivery.

This comprehensive guide explains everything you need to know about the anomaly scan, including its purpose, timing, procedure, findings, limitations, and frequently asked questions.

The anomaly scan helps detect structural abnormalities in the baby, but monitoring your own health throughout pregnancy is equally important. Symptoms such as severe headaches, blurred vision, reduced fetal movements, or vaginal bleeding require prompt medical attention. Our guide on warning signs in pregnancy explains these danger signs in detail and when to seek emergency care.

What Is an Anomaly Scan?

An Anomaly Scan is a detailed ultrasound examination performed during the second trimester, usually between 18 and 22 weeks of pregnancy.

Unlike routine pregnancy ultrasounds that mainly check fetal heartbeat and growth, a Level II ultrasound carefully examines every major organ and body structure of the baby.

The scan evaluates:

Brain
Face
Spine
Heart
Lungs
Kidneys
Stomach
Abdomen
Bladder
Limbs
Hands and feet
Placenta
Umbilical cord
Amniotic fluid
Cervix
Fetal growth

It is often called the “Target Scan” because every important part of the baby’s body is systematically examined.

Why Is the Anomaly Scan Important?

The anomaly scan is one of the most valuable prenatal investigations because it helps detect congenital abnormalities before birth.

Benefits include:

Checking whether the baby’s organs are developing normally
Detecting birth defects
Measuring fetal growth
Confirming gestational age
Evaluating the placenta
Assessing amniotic fluid
Checking cervical length
Identifying multiple pregnancies
Planning delivery if specialized neonatal care is required

Most anomaly scans show completely normal findings, giving parents reassurance.

The anomaly scan provides valuable information about your baby’s growth and development. As your pregnancy advances, it’s also the ideal time to compare delivery packages, estimate childbirth expenses, and understand health insurance benefits. Read our comprehensive guide on COST OF C-SECTION AND NORMAL DELIVERY IN DELHI to plan ahead with confidence.

When Is an Anomaly Scan Done?

The ideal timing is:

18–22 weeks of pregnancy

Many specialists prefer:

19–20 weeks

At this stage:

Baby’s organs are fully formed.
Structures are large enough to examine clearly.
Amniotic fluid provides excellent visualization.
If abnormalities are found, there is enough time for additional investigations and counselling.

Doing the scan too early may miss certain abnormalities because some organs are still developing.

Why Is It Called Level II Ultrasound?

Routine ultrasounds are often referred to as Level I scans, while the anomaly scan is a Level II ultrasound because it provides a much more detailed assessment.

Level II ultrasound includes:

High-resolution imaging
Detailed fetal anatomy
Organ-by-organ examination
Doppler assessment (when required)
Placental evaluation
Cervical assessment

How Is the Scan Performed?

The procedure is simple and painless.

Step 1: Gel Application

A warm ultrasound gel is applied over the abdomen.

Step 2: Ultrasound Probe

The sonologist moves the probe gently over your abdomen.

Step 3: Detailed Examination

The baby is examined from head to toe.

Numerous measurements are taken.

Images are recorded.

The radiologist documents all findings.

How Long Does It Take?

A routine anomaly scan generally takes:

30–45 minutes

Sometimes it may take:

60 minutes
Longer if the baby’s position is not favorable
Longer in twin pregnancies

The doctor may ask you to walk for a few minutes if the baby changes position.

Is the Scan Safe?

Yes.

Ultrasound uses sound waves, not radiation.

There is no evidence that medically indicated ultrasound harms the mother or baby.

It has been safely used worldwide for decades.

What Does the Doctor Check?

A systematic evaluation is performed.

1. Baby’s Head

The doctor examines:

Skull shape
Brain development
Cerebellum
Midline structures
Ventricles

Measurements include:

Biparietal diameter (BPD)
Head circumference (HC)

2. Baby’s Face

The scan checks:

Eyes
Nose
Lips
Upper lip
Facial profile

Conditions such as cleft lip may sometimes be detected.

3. Spine

The entire spine is examined to detect conditions like:

Spina bifida
Vertebral defects

4. Heart

One of the most detailed parts of the scan.

The doctor checks:

Four heart chambers
Heart valves
Major blood vessels
Cardiac rhythm
Heart rate

Some babies may require a fetal echocardiography if additional evaluation is needed.

5. Lungs

The lungs are examined for normal development.

6. Diaphragm

The doctor checks whether the diaphragm separates the chest and abdomen properly.

7. Stomach

The baby’s stomach should normally contain swallowed amniotic fluid.

8. Kidneys

Both kidneys are evaluated for:

Size
Position
Urine production

9. Bladder

A normal bladder indicates proper kidney function.

10. Abdomen

The abdominal wall is examined for defects.

11. Limbs

The doctor checks:

Arms
Legs
Hands
Feet
Fingers
Toes

Bone measurements are also taken.

12. Placenta

The scan identifies:

Placental location
Placental maturity
Placenta previa
Placental abnormalities

13. Umbilical Cord

The doctor evaluates:

Cord insertion
Blood vessels
Blood flow (if required)

Normally the cord contains:

Two arteries
One vein

14. Amniotic Fluid

The amount of fluid surrounding the baby is measured.

Too much or too little fluid may require additional monitoring.

15. Cervix

The cervical length is measured to assess the risk of preterm birth in selected pregnancies.

Measurements Taken During the Scan

Common fetal measurements include:

Head circumference
Biparietal diameter
Abdominal circumference
Femur length
Estimated fetal weight

These measurements help determine whether the baby’s growth matches the gestational age.

Can the Scan Detect Birth Defects?

Many structural abnormalities can be detected.

Examples include:

Brain abnormalities

Hydrocephalus
Neural tube defects

Heart defects

Congenital heart disease

Facial abnormalities

Cleft lip

Kidney abnormalities

Missing kidney
Enlarged kidneys

Limb abnormalities

Missing bones
Short limbs

Spine abnormalities

Spina bifida

Abdominal wall defects

Omphalocele
Gastroschisis

However, no ultrasound can detect every birth defect.

What Cannot Be Detected?

Some conditions may not be visible.

Examples include:

Mild heart defects
Certain genetic disorders
Intellectual disability
Autism
Hearing problems
Metabolic disorders
Very small abnormalities

Some abnormalities also develop later in pregnancy.

Can Down Syndrome Be Diagnosed?

The anomaly scan cannot diagnose Down syndrome.

However, it can detect soft markers that may increase the risk.

If multiple markers are present, your doctor may recommend:

NIPT
Amniocentesis
Genetic counselling

What Happens If an Abnormality Is Found?

Do not panic.

Many abnormalities require further evaluation before confirming the diagnosis.

Additional investigations may include:

Repeat ultrasound
Fetal echocardiography
MRI
Genetic testing
Amniocentesis
Consultation with a fetal medicine specialist

Early diagnosis helps parents make informed decisions and allows doctors to plan specialized care after birth.

Can Parents Know the Baby’s Gender?

In India, disclosure of the baby’s sex during pregnancy is illegal under the PCPNDT Act.

Radiologists and obstetricians are legally prohibited from revealing fetal gender.

Parents should avoid requesting this information.

How Should You Prepare?

Preparation is simple.

You should:

Wear comfortable clothing.
Carry previous ultrasound reports.
Bring blood test reports.
Carry your antenatal file.
Follow your doctor’s instructions regarding bladder filling.

Some centers may ask you to have a moderately full bladder.

Does the Scan Hurt?

No.

The procedure is painless.

Some women may experience mild pressure from the ultrasound probe, especially if the baby is positioned deep inside the pelvis.

What If the Baby Is Not Cooperating?

Babies frequently change position.

If visualization is poor, you may be asked to:

Walk for a few minutes
Empty your bladder
Drink water
Return after some time

Sometimes a repeat scan is needed to complete all views.

Who Should Definitely Have an Anomaly Scan?

Every pregnant woman should undergo this scan.

It becomes especially important if there is:

Diabetes
High blood pressure
Previous baby with birth defects
Family history of genetic disorders
Advanced maternal age
Twin pregnancy
IVF pregnancy
Abnormal screening tests
Exposure to certain medications or infections

Accuracy of the Anomaly Scan

The anomaly scan is highly accurate for detecting many structural abnormalities, but its accuracy depends on:

Baby’s position
Mother’s body habitus
Amount of amniotic fluid
Gestational age
Quality of ultrasound equipment
Experience of the sonologist

Even with an excellent scan, some abnormalities may not be visible.

Common Myths

Myth 1: The scan harms the baby.

Fact: Ultrasound is considered safe when performed for medical purposes.

Myth 2: The scan guarantees a perfectly healthy baby.

Fact: No scan can detect every condition.

Myth 3: The anomaly scan can tell the baby’s intelligence.

Fact: Intelligence cannot be measured by ultrasound.

Myth 4: One normal scan means no further scans are needed.

Fact: Additional growth scans may still be recommended later in pregnancy.

Tips for Parents

Schedule the scan between 18 and 22 weeks.
Keep all previous reports with you.
Eat normally unless instructed otherwise.
Stay relaxed during the examination.
Discuss the report with your obstetrician instead of interpreting it yourself.
Continue regular antenatal visits even if the scan is normal.

Conclusion

The Anomaly Scan (Level II Ultrasound) is one of the most important milestones in pregnancy. It offers a detailed assessment of your baby’s anatomy, growth, and development while helping detect many structural abnormalities before birth.

Although no ultrasound can identify every condition, the anomaly scan provides valuable reassurance in most pregnancies and allows timely planning when abnormalities are detected. Attending this scan at the recommended time and discussing the findings with your obstetrician ensures the best possible care for both mother and baby.

With regular prenatal check-ups, healthy lifestyle choices, and timely investigations, you can look forward to a safer and healthier pregnancy journey.

Frequently Asked Questions (FAQs)

1. When is the best time to get an anomaly scan?

Between 18 and 22 weeks, ideally around 19–20 weeks of pregnancy.

2. Is a Level II ultrasound different from a normal ultrasound?

Yes. A Level II ultrasound is a detailed examination of the baby’s anatomy, whereas a routine ultrasound mainly checks growth and heartbeat.

3. Is the anomaly scan painful?

No. It is a painless, non-invasive ultrasound performed over the abdomen.

4. Can the anomaly scan detect all birth defects?

No. It detects many structural abnormalities but cannot identify every condition or genetic disorder.

5. Do I need a full bladder for the scan?

Some centers recommend a moderately full bladder. Follow your doctor’s instructions.

6. How long does the anomaly scan take?

Usually 30–45 minutes, though it may take longer if the baby’s position makes imaging difficult.

7. Can I eat before the scan?

Yes, unless your doctor advises otherwise.

8. Can twins have an anomaly scan?

Yes. Each baby is examined individually with detailed anatomical assessment.