Home Health NT Scan: purpose, risks, procedure and results

NT Scan: purpose, risks, procedure and results



Prenatal examination and prenatal screening are crucial during pregnancy at regular intervals. Prenatal examinations for the expectant mother can reveal health problems, including anemiahypertension or gestational diabetes. Prenatal screening assesses the baby’s health and helps identify chromosomal abnormalities.

Women are tested for pregnancy in the first, second and third trimesters. Fetal screening in the first trimester provides early information about the health of the baby and detects chromosomal abnormalities.

Nuchal translucency test (NT) is one of many tests that doctors recommend for pregnant women. Doctors will schedule an NT scan between 11 and 13 weeks of pregnancy to check for possible abnormalities.

This blog is a complete guide to NT scanning, its purposes, risks, procedure and results.

What is an NT scan?

The NT scan (also known as the occipital transparency test) uses Ultrasound to assess the risk of the child developing Down syndrome and other chromosomal abnormalities. The inguinal transparency test measures the thickness of the inguinal fold. This is the area of ​​tissue at the back of the unborn baby’s neck. Measuring this thickness helps determine a child’s risk of Down syndrome and other genetic problems.

What is the purpose of NT scanning?

Doctors recommend NT scanning in the first trimester of pregnancy.

This is usually part of a combined first-trimester screening that includes an ultrasound and blood test. Ultrasound will confirm the pregnancy. In addition, a measurement of the fluid under the skin along the back of the baby’s neck, called the nuchal translucency (NT). The ultrasound will also try to measure whether the baby has a nasal bone.

A sample of the mother’s blood is used to measure free beta-human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and pregnancy-associated plasma protein A (PAPP-A), which is found in the blood of all pregnant women. In some pregnancies, when the baby is diagnosed with Down syndrome, trisomy 18, or trisomy 13, there is excess fluid behind the baby’s neck and/or hCG, AFP, and PAPP-A results are higher or lower than average. Combining the age-related risk with the NT measurement, nasal bone data, and blood test gives one risk number for Down syndrome and one risk number for trisomy 18 or trisomy 13.

People with Down syndrome have an extra 21st chromosome. Down syndrome is incurable and causes developmental delays. And Patau’s syndrome, and Edwards syndrome are rare and usually fatal. In most cases, children with Patau syndrome and Edwards syndrome die within the first year of life.

The combined first trimester screening is not a diagnostic test. This means it cannot tell if your baby has trisomy 13, trisomy 18 or Down syndrome. Instead, the screening offers a chance that the baby may have trisomy 13, trisomy 18, or Down syndrome.

When does the doctor prescribe an NT scan during pregnancy?

It is very important to complete an NT scan between 11-14 weeks of pregnancy as the empty space at the back of the developing baby’s neck may disappear.

How does NT scanning work?

The doctor will place a transducer (a small plastic device that sends and receives sound waves) above your abdomen. The reflected sound waves will be digitally converted into images on the monitor. Your doctor or technician will use these images to determine the size of the free space in the tissue at the back of your baby’s neck.

The expectant mother should remember that the NT scan cannot diagnose Down syndrome or any other chromosomal abnormality, but can only predict the risk.

Accuracy varies with any forecast. However, the accuracy of predicting the risk of Down syndrome is about 85 percent if a pregnant woman has both NT scans with a blood test. The accuracy rate drops to 75 percent if moms-to-be don’t combine the blood test with the scan.

Are there any risks to scanning NT?

NT scans are known to be risk-free, as ultrasound uses sound waves to produce images. It does not use any radiation. Women can have as many tests as they need without risk to themselves or their baby.

What do the NT scan results mean?

NT scan results are normal

A pregnant a woman gets a normal result if there is a normal thickness of fluid in the back of the baby’s neck during the ultrasound. The result means the baby is unlikely to have Down syndrome or another genetic condition. Measurement of nuchal translucency increases with gestational age, the period between conception and birth. The higher the indicator compared to babies of the same gestational age, the higher the risk of genetic disorders. The following measurements indicate a low risk of genetic diseases:

  • in the 11th week – up to 2 mm
  • at 13 weeks and 6 days – up to 2.8 mm

Abnormal NT scan results

There is a higher risk of Down syndrome, trisomy 13, trisomy 18, Turner syndrome, and congenital heart disease if the results show more fluid than usual in the back of the baby’s neck. However, it is unclear whether the child has Down syndrome or another genetic condition. If the results are abnormal, doctors recommend other tests called amniocentesis. The doctor takes a small amount of amniotic fluid from the uterus for analysis.

Another option is a chorionic villus sampling, a form of prenatal diagnosis in which a sample of tissue from a woman’s placenta is removed and examined for chromosomal abnormalities and genetic problems. There is a small risk of miscarriage with both tests.


The NT scan is a safe, non-invasive test that does not harm women or their babies. The patient should remember that this is a first-trimester examination that doctors recommend, but the examination is not mandatory. Some women skip this test because they don’t want to know about their risk. The expectant mother should consult with the doctor whether the patient feels restlessness or worry about how the results might affect them.

Frequently asked questions (FAQ)

1. How do women prepare for this exam?

Women should have a full bladder to get the best ultrasound picture. Before the test, the patient should drink 2 to 3 glasses of water per hour. The ultrasound procedure requires access to the lower abdomen, so women should make sure they wear comfortable clothing.

2. What sensations do women feel?

Women may experience discomfort from pressure on the bladder during ultrasound. The patient will not feel the ultrasound waves. During the test, the gel applied to the abdomen may feel slightly cold and wet.

3. Are there any consequences of scanning NT?

There are no side effects of abdominal or transvaginal ultrasound, and women can resume their normal activities immediately.

4. How long does the NT scan take?

The NT scan takes about 30 minutes.

Previous articleIs the new iPhone 14 waterproof? Here’s Apple’s explanation of water resistance
Next articleSNK: Terry Bogard was always planned to represent the Smash Bros Ultimate series