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.
A mid-pregnancy scan gives you a wonderful, detailed look at your baby’s anatomy, but nothing compares to the daily reassurance of feeling them active inside you. Learning your baby’s natural patterns helps you connect with them everyday. Find out how these visible scan movements translate into the flutters and rolls you feel by reading our guide on 🔍 Baby Movements During Pregnancy.
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.
The Importance of the Anomaly Scan in Your Pregnancy Journey
An anomaly scan, also known as a Level 2 ultrasound, is a crucial milestone in your pregnancy, typically performed between 18 and 22 weeks. As an essential part of your routine antenatal checkups, this detailed scan thoroughly examines your baby’s anatomy to ensure healthy structural development.
While your early pregnancy care and first-trimester tips focused on establishing a healthy foundation and viable heartbeat, the mid-trimester scan is all about monitoring growth. During this procedure, the sonographer evaluates the baby’s brain, heart, spine, kidneys, and limbs. If you are navigating a high-risk pregnancy, or actively managing conditions like thyroid disorders in pregnancy, this scan provides essential clinical reassurance about fetal well-being.
What Happens After the Level 2 Ultrasound?
In addition to anatomical checks, the ultrasound assesses your amniotic fluid levels and the position of the placenta. Following this scan, as your baby continues to grow stronger, you will soon start noticing baby kicks during pregnancy—one of the most exciting phases of the second trimester. It is important to complement these physical milestones with proper maternal nutrition, so be sure to follow a balanced pregnancy diet chart for Indian women to support your baby’s rapid development.
Understanding the various imaging requirements can sometimes feel overwhelming. You can read our comprehensive pregnancy ultrasound guide to know exactly what to expect at each stage of gestation. Moreover, while most anomaly scans yield normal results, understanding the signs of a high-risk pregnancy can help you seek immediate medical attention if you ever feel uncomfortable. To ensure a smooth journey, familiarize yourself with common pregnancy problems and their natural management.
Global Standards and Medical Guidelines
To ensure the highest level of maternal safety and diagnostic accuracy, clinical ultrasound protocols are strictly governed by international medical frameworks. You can learn more about standard imaging procedures by reviewing the American College of Obstetricians and Gynecologists (ACOG) guidelines on ultrasound in pregnancy.
Additionally, sonographers worldwide rely on the Fetal Medicine Foundation (FMF) standards for mid-trimester scans to provide evidence-based protocols for anomaly detection. Combining these imaging standards with the World Health Organization (WHO) recommendations on comprehensive antenatal care ensures that both mother and baby receive the safest, most effective healthcare possible.
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.
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.
Author
Dr. Mamta Agrawal
DGO, Obstetrician & Gynecologist
