Anomaly Scan in Pregnancy: Its Benefits, Preparation, Procedure, and More

Are you expecting a baby?

Or 

Do you know someone who is in their 20th week of pregnancy?

We are asking you this question to inform you about the 20-week ultrasound (anomaly scan) recommended to check the fetus's physical development. It is a prenatal ultrasound performed between 18 and 22 weeks of pregnancy. 

Also known as an anatomy scan or fetal anomaly test, it is a prenatal screening that examines each part of the fetal body, determines the position of the placenta, measures fetal growth, and evaluates amniotic fluid. 

A 20-week pregnancy is vital in letting you know if the fetus is growing appropriately. The ultrasound technician or sonographer takes certain measurements of your fetal organs and body parts, such as the heart, brain, neck, spine, hands, fingers, feet, and toes, to detect congenital disabilities. 

Disclaimer: The anomaly scan also helps learn the sex of a child. However, sex determination is strictly prohibited in India, and Redcliffe Labs also doesn’t encourage the same. 

Today’s blog discusses abnormal scans, when they are done, the procedure, preparation, and some frequently asked questions. 

Understanding: Anomaly Scan in Detail

Pregnancy is a very beautiful phase of a woman’s life. She wants to enjoy every bit of it. The first trimester of a pregnancy phase is crucial. During these three months, the baby’s body structure and organs develop. 

During the second trimester, and sometime between 18 and 22 weeks of pregnancy, you will likely feel your baby move. This is referred to as “quickening.” Indeed one of the greatest joys. Additionally, during this period, the doctor suggests an anomaly test to get done. 

An anomaly scan examines each part of your developing baby, emphasizing the brain, spine, face, kidneys, limbs, stomach, bowel, and spine. The doctor also checks other parts of your body to determine the presence of rare abnormalities related to the brain, spine, and heart. 

If abnormalities are detected, expecting parents have an opportunity to discuss them further with the specialist and get the best advice possible. 

Also read: https://redcliffelabs.com/myhealth/pregnancy-test/pregnancy-scan-list-important-scans-during-each-trimester/

When is the anomaly scan done?

The anomaly scan is done in the 20th week of pregnancy. The anatomy scan is a prenatal ultrasound that checks on the fetus's physical development and detects certain congenital disorders and major anatomical abnormalities. These may include abdominal wall and limb reduction defects, skeletal dysplasia, and multiple congenital anomalies.

Specific parts that your doctor will examine during the Anomaly scan: 

The specific part that your doctor will examine includes eleven conditions of your baby revealing congenital disabilities or structural issues with certain organs: 

1. Heart 
2. Brain
3. Neck 
4. Arms and legs
5. Hands, feet, fingers, and toes
6. Kidney and bladder 
7. Lips, chin, nose, eyes
8. Face
9. Chest and lungs
10. Stomach and intestines
11. Spinal cord

The 18-22 weeks of pregnancy is a very interesting phase in your life. Your body goes through major transitions such as:

• Stretch marks on abdomen, breasts, and hips
• Dark line around the abdomen area
• The disappearance of the waistline because the uterus is approximately the navel 

Further, this major transition also impacts you emotionally, making you feel differently. Your body and mind get adjusted to these changes, which give you mixed feelings about a pregnancy episode. 

Preparation for a 20-week anomaly scan

No special preparations are to be made for a 20-week anomaly scan. Keeping a few guidelines in mind can help you get the most accurate results:

• Wear loose clothes to make scanning easier. 
• Keep your bladder full. 
• Don’t be late for a scan. If possible, reach early. 
• Carry your maternity documents to help a doctor understand your pregnancy history. 

What happens during an anomaly scan?

The main purpose of an anomaly scan is to assess your pregnancy completely. The test is performed at about 20 weeks of pregnancy, when your baby and womb (uterus) are closely monitored. 

This mid-pregnancy test is suggested between 18 weeks and 20 weeks. 6 days of pregnancy usually takes 30-40 minutes. The expert takes measurements of your fetal organs and other body parts, ensuring the fetus’ growth is appropriate. The name fetal signifies examining each part of the fetal position, covering: 

• Head circumference (HC) denotes the length surrounding the baby’s head. 
• Abdominal circumference (AC) denotes the length surrounding the baby’s abdomen. 
• Femur or thigh bone (FL): It measures the femur or the thigh bone length. 
• Humerus or arm bone: It is the long bone. 

Additionally, a 2D, 3D, or even 4D ultrasound scan will be used to assess the baby's complete health and development. 

Step-by-Step information on how an anomaly test is conducted:

• First, during an anomaly test, a sonographer applies a gel over the belly in a dimly lit room to capture the most accurate images. 
• Second, the ultrasound technician applies a gel on the probe and moves it thoroughly over your skin to create a clear image of the fetus. 
• Third, the doctor will mention your baby’s heartbeat, face, and hands during the process. 

What more can you expect?

• The anomaly scan may take longer depending on your baby’s movement into a more favorable position.
• The doctor looks at every organ of your baby from a possible angle and section. Consequently, your baby’s face appears white, and its soft tissue structures look grey and speckled. 
• The expert will also check your baby’s placenta and uterine blood flow. 
• You may be asked if you would like to see your baby's face. 

What does the anomaly scan result mean?

A fetal anomaly test provides a detailed picture about the unborn child to its expecting parents. The test can identify defects or potential abnormalities ( if any). 

Most parents learn about the absence of a rare condition in their unborn child, indicating appropriate growth and development of a child in the fetus. 

Additionally, some expecting individuals will be told about the baby having a sign of a condition which needs further evaluation. 

Nevertheless, additional screenings, such as amniocentesis or chorionic villus sampling, may also be required to confirm chromosomal, genetic disorders, or congenital disabilities (sometimes called congenital disabilities). 

Below is a table showing the sort of problems that can be found during an anomaly test:

Problems/Congenital Abnormality	What does it mean?	% of being detected during the anatomy test
Spina Bifida	Gap in the spine	>90%
Anancephaly	The baby is without the brain and skull parts at birth	99%
Hydrocephalus	Excess cerebrospinal fluid (CSF) within the brain.	60%
Major Congenital Heart problems	60%
Diaphragmatic Hernia	Abnormal opening in the diaphragm.	60%
Major kidney problems	Missing or abnormal kidneys	85%
Major limb problems	Missing or abnormal limbs	90%
Autism	Communication, learning, and behavioral problems	Never seen
Down syndrome	Heart and bowel problems	approx. 50-60%
Gastroschisis	The intestines of the baby extend outside the abdomen	approx. 50-60%

Note: Many deformities are discovered late in pregnancy or even after the birth. Talk to your doctor early in your pregnancy to understand the types of tests you may need. Several other tests are available to detect the increased risk of congenital disabilities that are prescribed before 20 weeks of pregnancy. 

 

Importance of Anomaly Scan Test

An anomaly or fetal anomaly scan is important to detect rare conditions that may develop in your baby during pregnancy. If suggested, you should not delay and get your anomaly test done because: 

• It focuses on the heart, spine, and brain. 
• Any ultrasound scan can pick visible defects. However, anomalies related to those in the brain, skull, or kidney can be detected in the mid-pregnancy. 
• The test also determines rare conditions associated with heart, cleft palate, or tracheoesophageal fistula. Additionally, it reveals with utmost accuracy whether treatment after birth or a surgical procedure is to be performed for the baby's development and growth. 
• The test is 100% safe and performed clinically to detect potentially life-altering anomalies. 
• In most cases, the test also helps you learn about the child’s sex. 

Note: Sex determination and sex selection are strictly not allowed in India to protect the rights of unborn girls and restore gender balance. 

Are there any limitations of the anomaly scan?

Yes, an anomaly scan has some limitations, including:

• Some anomalies are detected late in pregnancy, not during the 18-20 weeks window. 
• The test cannot detect certain anomalies due to factors such as obesity, the baby’s position, twins or triplets, or overlapping babies. 
• An anatomy scan cannot detect cerebral palsy, autism, and fusion of fingers/toes, absence of anal opening or auditory opening. 
• Many developmental activities occur in the second trimester of pregnancy, which doesn’t guarantee 100% that you will have a healthy baby at 40 weeks. 

Conclusion

A 20-week ultrasound scan will help you see the fetus and determine how it is developing. Pregnancy is a crucial phase in a woman’s life, and getting normal and excited is absolutely normal. 

Talk to your healthcare provider in case of doubts or concerns so that they can plan treatment, including important tests, assuring worry-free pregnancy. 

If suggested, you need not worry. Book your appointment for an anomaly scan, which is usually a positive experience. 

Additionally, blood tests are often suggested during pregnancy to detect anemia, Down’s syndrome, sickle cell anemia, thalassemia, and other conditions. You can call or download the Redcliffe Labs mobile app to book a blood test online with home sample collection. Get the most accurate reports within a time frame. 

Step-by-step information on booking a test online from Redcliffe Labs. 

1. Visit the official Redcliffe Labs website: https://redcliffelabs.com/.
2. Browse or search for the specific test you need. 
3. Add the test to the cart. 
4. Complete the payment process online.

Note: You will receive confirmation through SMS and WhatsApp. 

FAQs: 

1. When is an anomaly test suggested?

An anomaly test is suggested during the second trimester when you're between 18 and 21 weeks pregnant. 

2. What conditions does an anomaly test detect?

An anomaly test helps detect spina bifida, cleft lip, anencephaly, chromosomal abnormalities, renal agenesis (missing of kidneys), and abdominal wall issues. 

3. What cannot a 20-week anomaly scan in pregnancy detect?

A 20-week anomaly scan cannot detect many heart abnormalities until birth, scoliosis, autism, and cerebral palsy, among others. 

4. What is the need for additional testing or ultrasounds?

Additional testing or ultrasounds may be needed when a healthcare provider suspects anything worrisome in your 20-week scan or if it is a high-risk pregnancy.