What is a Nuchal Translucency Scan (NT scan)?
A Nuchal Translucency (NT) scan is an ultrasound scan taken between 12 to 13 weeks of your gestation. This scan is performed to rule out any structured malformations caused by chromosomal abnormalities in the fetus.
Nuchal Translucency is the fluid-filled space behind the baby’s neck. NT scan checks this fluid space and the nasal bone of the baby. The nasal bone is a bright echogenic space found between the tip of the baby’s nose.
In addition to this, the blood flow and various other body parts visualized in the first trimester are also examined.
Best NT Scan in Chennai
Chennai Women’s Clinic at T.Nagar (Homepage internal link) is the top choice for NT Scan in Chennai by many moms-to-be. We at Chennai Women’s Clinic offer you the best obstetric scan services in Chennai, providing you and your unborn with a clean and positive environment.
Here, your scans are done by the award-winning Obstetrician and Gynecologist in the city, Dr. Deepthi Jammi (Founder & Fetal Medical Consultant, Chennai Women’s Clinic). Our doctor and her team give their best to ensure premium-level health for you and your child.
When Is The NT Scan Taken?
Does a low-risk first-trimester blood test guarantee a healthy baby?
Why should you take an NT scan?
How to identify Down's Syndrome

What happens if a baby is in the high-risk category
- You are offered genetic counseling by your fetal expert if,
- Your NT scan detects the presence of abnormalities in the baby along with any soft markers. Soft markers are fetal sonographic findings that indicate an underlying chromosomal or non-chromosomal abnormality.
During the genetic counseling, your fetal expert recommends two different types of confirmatory testing,
- An invasive diagnostic procedure called Chorionic villus sampling (CVS): During this procedure, you will be guided by a scan to pass a needle through your abdomen to collect chorionic villi (placental tissue) samples for testing. This is a 100% confirmatory test for any chromosomal disorders in your baby.
- Non-invasive Prenatal Screening (NIPT): The procedure involves collecting 20ml of your blood from the arms to test for its fetal cells. In general, this analysis is not done in India. Rather the sample is sent abroad for analysis. This is a high-quality screening test and carries no chances of miscarriage. In contrast, the CVS procedure is usually a confirmatory test and carries a small risk percentage of miscarriage.

What can be done if you miss the first trimester NT scan
A second-trimester (16 to 20weeks) screening test is offered if you have missed the first trimester NT scan. However, the test sensitivity for Down’s Syndrome in this is lower than the first trimester NT scan.
- An invasive diagnostic procedure called Chorionic villus sampling (CVS): During this procedure, you will be guided by a scan to pass a needle through your abdomen to collect chorionic villi (placental tissue) samples for testing. This is a 100% confirmatory test for any chromosomal disorders in your baby.
- Non-invasive Prenatal Screening (NIPT): The procedure involves collecting 20ml of your blood from the arms to test for its fetal cells. In general, this analysis is not done in India. Rather the sample is sent abroad for analysis. This is a high-quality screening test and carries no chances of miscarriage. In contrast, the CVS procedure is usually a confirmatory test and carries a small risk percentage of miscarriage.
Note: An early anomaly scan is performed before this test. And if your anomaly scan doesn’t show any significant abnormalities, you are not recommended with quadruple testing. However, you will be recommended with an Amniocentesis in case of any abnormalities. This is an invasive procedure where a needle is passed through your abdomen to collect the amniotic fluid surrounding the baby for testing.
Frequently Asked Questions
An NT scan measurement upto 2.8mm around 13weeks is considered as normal
NT scan is an ultrasound scan that mainly helps to assess your developing baby’s risk of having Down syndrome and some other chromosomal abnormalities. While an anomaly scan is used to look for any abnormalities in your baby’s body parts.
An NT scan takes about 20 minutes to 30 minutes for completion.
NT scans are not painful. They sometimes might cause discomfort as you may feel some pressure when the sonographer presses on your abdomen to get a clear picture.