NT Scans

NT Scans And Prenatal Screening

What is an NT Scan?

An NT scan, or Nuchal Translucency test is an ultrasound scan that is generally done between 11 and 14 weeks of pregnancy (First Trimester) to determine a fluid-filled space behind the baby’s neck which is known as nuchal translucency.

This scan is performed to rule out any chromosomal abnormalities in the fetus.

In addition to this, the blood flow and various other body parts visualized in the first trimester are also examined and also risk for pre eclampsia will be established.

When is the Best Time to Have an NT Scan?

The best time to take an NT scan is during the first trimester, which is between 11 and 14 weeks of pregnancy. Preferabally between 12- 13 weeks because the visualisation of fetal organs is much appreciated at this time and gives accurate NT scan results.

How is a nuchal translucency scan done?

A nuchal translucency scan is done using a handheld ultrasound wand. The wand may be placed on your abdomen (tummy) or in your vagina. Your sonographer will decide based on things like:

• How far along your pregnancy is?
• The position of your baby?
• Your body shape?

The ultrasound wand or probe transmits ultrasound waves. The soundwaves are sent to your baby and back to the ultrasound machine to produce images or pictures on the screen.

Can a nuchal translucency scan harm my baby?

Ultrasounds do not harm you or your baby or increase your risk of miscarriage. No needles or radiation are used.

Is NT Scan Painful?

The answer is NO; the nuchal translucency scan is not painful. The NT scan is a safe and non-invasive ultrasound scan.

Why is NT Scan Performed during Pregnancy?

The nuchal translucency NT scan is done to

1. Identify the risk of chromosomal abnormalities like Down syndrome, trisomy 13 (Patau syndrome), and trisomy 18 (Edwards syndrome) in the fetus.
2. To screen for the risk for pre-eclampsia
3. To screen for structural abnormalities in fetus

What is Double Marker Test?

The double marker test is a blood test that is done along with the NT scan to detect any chromosomal abnormalities in the fetus.

It measures the levels of PAPP-A (pregnancy-associated plasma protein A) and beta hCG (beta-human chorionic gonadotropin) hormones in the blood.

Is a Double Marker Test Necessary After an NT Scan?

The double marker is a mandatory test and may be recommended by your gynecologist.

The NT scan gives information about the risk of chromosomal abnormalities in the fetus, whereas the double marker test provides extra information about your pregnancy.

What do the nuchal translucency scan results mean?

Your nuchal translucency scan measurement is combined with a blood test to work out the ‘combined first-trimester screen’ result. The calculation also includes your age.

This is a screening test, so the results can’t tell you for sure whether your baby has a genetic condition. Results are usually reported as ‘low risk’ or ‘high risk’.

If you have a ‘low risk’ result, it means it is less likely that there is an abnormality present. If you have a ‘high risk result’ it means it is more likely that there is an abnormality present.

If your test returns a ‘high-risk’ result, your doctor can refer you for further testing. You may decide to have a diagnostic test, which can give you a definite result. You can also go for genetic counselling to help you understand the result.

Diagnostic tests for your baby include:

• Chorionic villus sampling (tests the placental tissue)
• Amniocentesis (tests the amniotic fluid — the fluid around your baby)

How should I prepare for a nuchal translucency scan?

It’s a good idea to come with a calm and relaxed mind.

On the day, drink a glass of water so that there is fluid in your bladder when you arrive. Wear loose clothes so that the sonographer can easily reach your abdomen. Carry a small snack along with you , if the baby is not in a good position for the scan you might need to spend more time in the hospital.

How long does NT scan take?

An NT scan takes about 20 minutes to 30 minutes for completion.

In general, you will receive the NT scan result immediately. However, it may vary based on your scan centre.

What can be done if you miss the first trimester NT scan?

A second-trimester (16 to 20 weeks) screening test is offered if you have missed the first-trimester NT scan.

However, the test sensitivity for Down Syndrome in this is lower than the first trimester NT scan.

Can my husband come along too?

Yes. You can bring your husband to your ultrasound appointments.

It can be good for your husband also to be involved in every part of your pregnancy journey and listen to the information provided.