Essential Guide to the Anomaly Scan: What to Expect and Understand
The anomaly scan, also known as the anatomy scan or 20 week scan, is one of the most important ultrasound scans during pregnancy. It is typically performed around the 18th to 22nd week of gestation and helps examine the development of the baby and the maternal pelvic organs. This scan is routine and offered to all pregnant women to check for fetal anomalies, structural abnormalities, and monitor fetal growth.
What Is an Anomaly Scan?
An anomaly scan is a detailed second-trimester ultrasound that focuses on the fetal anatomy. It uses high-frequency sound waves to produce detailed images of the baby inside the womb. The scan evaluates fetal organs, measures the size of the fetus, and checks the location of the placenta.
It can also help determine the fetal number and detect issues like cleft lip or congenital conditions, reducing the risk of an undiagnosed problem. A 4D anomaly scan may be offered in some clinics using advanced ultrasound technology.
Why the Anomaly Scan Is Important
Anomaly scans are critical in assessing the baby’s growth and development. It helps identify:
- Structural abnormalities in fetal structures like the brain, heart, and limbs
- Soft markers that may indicate chromosomal abnormalities, such as Down syndrome
- The health of the placenta and the amount of amniotic fluid
- The position of the fetus and the umbilical cord
- Facial abnormalities such as a cleft lip
This scan provides valuable information to doctors and helps in early detection of conditions that might need further evaluation, planning, or treatment.
What to Expect During the Anomaly Scan Appointment
The anomaly scan, often referred to as a trimester anomaly scan, is usually done between 18 to 22 weeks of pregnancy. It is often a routine part of prenatal care and helps ensure that both mother and baby are doing well. Here is what you can expect:
1. Arrival and Preparation: You’ll be asked to arrive with a moderately full bladder. This improves visibility during the scan. You may be asked to lie down on a bed while the ultrasound technician applies ultrasound gel to your abdomen. This gel helps the ultrasound probe make better contact with the skin.
2. The Scanning Process: The ultrasound technician will use a handheld device called a probe to glide over your abdomen. This probe sends and receives sound waves, creating a scan image on a monitor. The scan may take 30 to 45 minutes, depending on the fetal position and movement.
3. Clarity of Scan: The quality of the images depends on several factors like fetal size, fetal movements, the amount of amniotic fluid, and maternal body type. Sometimes, the baby’s position may prevent clear images, and you might be asked to walk around or return later.
4. What the Technician Looks For: The technician looks at the fetal brain, spine, face, heart, kidneys, abdomen, limbs, and several other body parts to ensure proper development. They also examine the placenta, umbilical cord, and maternal pelvic organs. This gives a comprehensive assessment of both fetal and maternal well-being.
5. Post-Scan Process: You may receive a printed scan image. A detailed report is usually shared with your doctor, who will explain the findings. If any anomalies are detected, you may be referred for further evaluation or a specialist opinion.
How to Prepare for the Anomaly Scan
Preparation can help make your anomaly scan smoother and more effective, especially when considered from early pregnancy . Though it’s a simple process, a few steps can make the experience more comfortable and ensure clear results.
- Bladder: You may be asked to come with a moderately full bladder. This can help create a clearer scan image by pushing the uterus up.
- Clothing: Wear loose-fitting clothes that allow easy access to your abdomen.
- Food Intake: You can eat normally before the scan. Some movement from the baby can actually help the technician get better images.
- Questions: Write down any questions or concerns you have ahead of time. It’s easy to forget them in the moment.
- Support: Bring your partner or a close friend if allowed by the clinic. Their presence can offer emotional support.
Understanding what to expect and planning ahead, including discussing your family history, makes the scan less stressful and more productive for both you and your healthcare provider.
What the Anomaly Scan Looks At: Detailed Checklist
The anomaly scan involves a detailed evaluation of the baby’s body to look for any signs of developmental or structural abnormalities, enhancing the detection rate of potential issues. The scan uses sound waves to generate images of the fetal anatomy, helping doctors examine internal organs, the fetal head, and overall growth. It’s typically performed during the second trimester to ensure that major fetal structures are forming correctly.
- Fetal Brain and Head: During the scan, the ultrasound technician will check the shape of the fetal head and look inside the brain. Measurements of the head help verify gestational age and rule out concerns such as fluid build-up or abnormal brain structures. The cerebellum, ventricles, and midline of the brain are specifically observed for symmetry and normal growth.
- Facial Features and Spine: Facial abnormalities such as cleft lip are assessed by carefully scanning the baby’s profile and upper lip. The spine is checked from the neck to the lower back to ensure it is properly aligned and closed. The technician will capture both cross-sectional and longitudinal images of the spine to check for neural tube defects.
- Heart and Chest: The scan examines the fetal heart for its position, size, and function to identify any potential complications . All four chambers, the outflow tracts, and heart valves are studied. Blood flow patterns are reviewed using Doppler ultrasound. Lung development and chest wall structure are also reviewed to rule out any malformations in the thoracic cavity.
- Abdomen and Kidneys: Fetal abdominal circumference is an important measurement to evaluate fetal growth. The scan checks the stomach, bladder, and abdominal wall to detect hernias or other issues. Both kidneys are identified and examined for their location, size, and function to make sure the urinary system is developing normally in preparation for birth.
- Limbs and External Genitalia: The scan looks at arms, legs, fingers, and toes for proper length and structure. Any limb shortening or missing bones can be detected. The technician will also identify the external genitalia if you choose to know the baby’s sex. Multiple fetuses, if present, are also confirmed during this stage.
Checklist Table
| Structure Assessed | What Is Checked |
|---|---|
| Fetal Brain and Skull | Shape, ventricles, midline, cerebellum |
| Facial Features | Nose, lips (cleft lip), jaw |
| Heart | Four chambers, valves, blood flow |
| Abdomen | Organs, abdominal wall, stomach, bladder |
| Kidneys and Limbs | Presence, size, location, limb movement |
Understanding Your Anomaly Scan Results
After the anomaly scan, the ultrasound technician compiles a report, which may include references to any previous reports that provide contex . This is reviewed by your obstetrician, who discusses the findings with you. In most cases, the results indicate normal fetal development. However, sometimes the scan might show minor or significant concerns that need further medical attention.
What may happen next:
- You might be advised to repeat the scan if the baby’s position made it hard to see certain structures clearly.
- You may be referred to a fetal medicine specialist for more advanced evaluation.
- Soft markers or structural signs may lead to discussions about genetic counseling or additional diagnostic tests.
The anomaly scan is designed to look at fetal anatomy, but not all conditions can be seen in most hospitals . Some problems may not be visible at this stage or may develop later in pregnancy. Your doctor will guide you if any follow-up steps are necessary. Stay open to asking questions and discussing all concerns during your follow-up visit.
Common Myths of Anomaly Scan
There are several myths about anomaly scans that often cause unnecessary concern among pregnant women. Let’s clarify a few of them.
- Myth: Anomaly scan guarantees a healthy babyThe scan helps detect many issues but not all. Some problems may not appear until later.
- Myth: If the baby moves too much, the scan won’t work Movement is normal. Technicians are trained to adjust and capture images.
- Myth: Anomaly scan is harmful to the baby The scan uses sound waves, not radiation. It is safe.
- Myth: A clear scan image means no issues A good image does not rule out all problems. Some conditions are too subtle or develop later.
- Myth: Gender prediction is the main aim This scan is for health checks. Finding out the gender is optional and secondary.
Emotional Aspects: Managing Anxiety Before and After the Scan
Feeling nervous about the anomaly scan is normal. For many, it brings reassurance. For others, it may bring questions or concerns.
- Before the scan
- Talk to your doctor about the process.
- Bring a partner or friend if allowed.
- Avoid googling symptoms or conditions.
- After the scan
- Give yourself time to process the results.
- Ask your doctor to explain any unclear points.
- Speak to a counselor if you feel overwhelmed.
The scan is designed to check the baby’s health and help you make informed decisions. Try to stay calm and informed throughout.
Together We Care: SRM Global Hospitals
At SRM Global Hospitals, we support every pregnancy with care and technology. Anomaly scans are a key part of our fetal imaging services. We use advanced ultrasound technology to assess the baby’s development during the second trimester. Our experienced team ensures each scan is detailed, safe, and clear.
We know how important this step is to measure fetal growth and overall health. The results help track fetal growth, detect fetal anomalies early, and monitor overall well-being. If an issue is found, our specialists will guide you with clarity.
Your comfort is our priority. From ultrasound gel application to post-scan consultation, every step is managed with care. With us, you are not alone.
Book your 20-week scan at SRM Global Hospitals today.
FAQs
1. When is an anomaly scan done during pregnancy?
An anomaly scan, often referred to as an anatomy scan, is typically performed between 18 and 22 weeks of pregnancy. This period is ideal because the fetus is developed enough for a detailed scan, but still small enough to get clear views of all structures. It’s also called the second trimester ultrasound or trimester anomaly scan.
2. What is checked in the 4D anomaly scan?
A 4D anomaly scan shows real-time moving images of the fetus. It checks fetal anatomy, facial features, limbs, and fetal movements. It can also help evaluate soft markers, amniotic fluid levels, and blood flow. Some parents prefer this version for clearer views and emotional connection.
3. What happens if an abnormality is found?
If the scan detects a structural or chromosomal abnormality, the doctor may suggest further evaluation. This may include another scan, blood tests, or referral to a fetal medicine specialist. The goal is early detection and proper planning for birth and beyond.
4. Does the anomaly scan hurt?
No, an anomaly scan does not hurt. Some women may feel mild pressure from the ultrasound probe, especially if the technician needs to press down for better images. The process is non-invasive and safe for both mother and baby.
5. Can I eat before the scan?
Yes, you can eat before the anomaly scan. In fact, some food intake might help the baby move, which could improve image quality. Just remember to keep your bladder moderately full, as instructed by the clinic or hospital.
