During pregnancy, the expecting mother gets multiple scans and ultrasounds to check on the baby’s growth and development. These scans are spaced according to the developmental milestones of the fetus. The anomaly scan is one such important scan done in the middle of the pregnancy period to ensure the baby’s development is on track.
Anomaly scan also known as the anatomy scan is an ultrasound scan taken during the 20th week of pregnancy. It is a screening scan that looks for 11 different conditions that could possibly affect a developing fetus. It also checks if the baby is growing as per expectations.
This scan is usually taken between weeks 18 and 21 of pregnancy. After the 21st week, it could be too late, and before the 18th week, not everything may be visible. In very rare cases, the scan could be taken until the 23rd week, too. However, doctors don’t prefer to push it this far.
In an anomaly scan, a 2D, 3D and 4D image of the baby is taken. The baby is measured through these images to ensure the growth is appropriate for the gestational age.
Though the scan checks for 11 specific issues, it may not find everything. Some conditions can be more clearly visible than others, so there are chances of the scan missing out on some health or developmental issues too.
The 11 conditions the anomaly scan checks for are:
1. Anencephaly – A serious deformation of the brain and skull
2. Open spina bifida – The spinal column is not closed properly
3. Cleft lip and palate – Face and mouth do not fuse properly
4. Diaphragmatic hernia – Abdominal contents push into the chest cavity
5. Gastroschisis – Organs are outside the body
6. Exomphalos – Abdominal wall does not develop fully
7. Serious cardiac abnormalities
8. Bilateral renal agenesis – Both kidneys are not present
9. Severe skeletal dysplasia – Abnormal development of bones and joints
10. Edwards' syndrome or Trisomy 18 – A genetic condition that causes growth delays
11. Patau's syndrome or Trisomy 13 – An extra copy of chromosome 13 is present in the cells.
The anomaly or anatomy scan is not compulsory. It is highly recommended to ensure the baby is developing well and does not have one of the 11 conditions mentioned earlier. However, if you don’t want to take the scan, you can always opt out. It is advisable to discuss your concerns and reservations in detail with your midwife or doctor before you decide to skip this important scan.
The scan can identify possible issues in the baby’s heart, brain, spine, skull as well as limbs. This can be crucial information for both parents and the doctor. The doctor can start tracking the fetal development very closely and parents can get counselling.
The anomaly scan is a non-invasive ultrasound that involves a hand-held probe. The sonographer will apply a gel on the stomach and use a hand-held probe to get images of what is inside.
If the baby is in a good position, the scan should not take more than a few minutes. However, if the baby is facing sideways or backwards, getting accurate images can be challenging. The healthcare provider might try to gently nudge the baby or ask you to go for a walk. If the baby does not change positions, you may have to wait a while longer or come back another day.
Since this is an important scan in pregnancy, there are no shortcuts or compromises.
If the ultrasound picks up something odd during the anomaly scan, the doctor will ask for more specific scans and tests. The parents can then discuss the findings and undergo counselling. This prepares them to support a child with issues that are most probably permanent in nature.
● Amniocentesis – In this test, the doctor will remove a sample of the amniotic fluid using a syringe. This fluid is analysed further to test for Down’s syndrome, Edward’s syndrome or Patau’s syndrome.
● Chorionic villus sampling (CVS) – In this test, a sample of the cells is removed from the placenta for further analysis. This test also checks for Down’s syndrome, Edward’s syndrome or Patau’s syndrome.
Both these tests are not routine tests and are recommended only if the baby is at a high risk of genetic or chromosomal condition. The health issues these tests identify are mostly not curable. So, you need to discuss your options with your doctor.
Parents can undergo counselling to learn how to be supportive of a child with birth defects or can even choose to terminate the pregnancy. Different countries have different laws, so it is important to be aware of the rules and limitations in your country.
The anomaly scan is one of the most important screening scans done in pregnancy. It can help identify potential birth defects and health issues with the baby. Though not compulsory, it is highly recommended to take this scan. The scan is safe and you lose nothing by taking this important scan.
The anomaly scan can detect the possible presence of 11 different health conditions. The scan can check for abnormalities in the skull, abdomen, skeletal structure, spine, heart, kidneys, limbs as well as facial features. One of the most common conditions this scan checks for is Down Syndrome.
If the ultrasound picks any abnormalities, they will take more scans and tests to confirm the suspicion. They will take a sample of the amniotic fluid for further analysis. This fluid can confirm if the baby does have a health condition. Based on the results, your doctor can refer you to a specialist to advise you on the next course of action.
Yes, they are safe for both mother and baby. The anomaly scan is a non-invasive procedure and does not emit any kind of radiation. It does not cause any harm.
