Nuchal Translucency Screening
Nuchal translucency screening is a noninvasive test doctors perform during pregnancy. It measures the growing baby’s risk of having certain chromosomal abnormalities and heart conditions. It is also called an NT scan or first trimester screening.
Nuchal translucency screening involves having an ultrasound of your abdomen in the first trimester of pregnancy. During the ultrasound, the healthcare provider measures the thickness of the tissue at the back of the fetus’ neck. This tissue is called the nuchal translucency. Thicker-than-normal nuchal translucency means that the baby has a higher risk of an abnormality.
A nuchal translucency screening is optional. It is also only one method used to screen for fetal abnormalities. Discuss all of your screening options with your doctor to understand which ones are right for you.
Other procedures that may be performed
Doctors often combine nuchal translucency ultrasound with a blood test. The blood test looks for the presence of certain proteins that also indicate higher risk of chromosomal conditions. This combination of nuchal translucency screening with a blood test is a first trimester screening.
Your doctor may recommend nuchal translucency screening to assess your baby’s risk of certain diseases and conditions. This includes chromosomal abnormalities, such as Down syndrome and trisomy 18, and congenital heart conditions. The nuchal translucency screening test is considered more accurate than other screening tests done in the second trimester.
If the results show a high risk, this does not necessarily mean that your baby has a problem. It means you need to decide if you would like to have a diagnostic test. A diagnostic test can provide a firm answer about any abnormalities. Amniocentesis and chorionic villus sampling are prenatal diagnostic tests.
The following specialists commonly perform nuchal translucency screening:
Obstetrician-gynecologists (Ob/Gyns) specialize in the health needs of women including caring for pregnant women and their unborn children.
Perinatologists, also called maternal-fetal medicine specialists, are doctors who specialize in high-risk pregnancies, which is when there is a greater risk of maternal or newborn complications.
Ultrasound technicians are specialists in performing ultrasound. If a technician performs your nuchal translucency ultrasound, an Ob/Gyn or perinatologist will review the results and discuss them with you.
Your nuchal translucency screening will be performed in a doctor’s office, clinic, or ultrasound department of a hospital. The procedure takes 30 to 45 minutes. If you have a blood test during the same appointment, you should be finished in an hour. A nuchal translucency screening generally includes these steps:
The ultrasound technician or doctor will smooth a water-based jelly on your abdomen.
The ultrasound technician or doctor will then move an ultrasound wand gently back and forth across your skin. He or she may gently press the wand down at times to obtain more accurate readings.
- The ultrasound technician or doctor will wipe off the gel once the exam is complete.
There are no known risks of having a nuchal translucency screening. Ultrasound exams like the nuchal translucency screening use harmless sound waves to produce images of your developing baby.
Will I feel pain?
You should not feel pain during the procedure. You may feel minor discomfort when the doctor or ultrasound technician presses into your belly. This feeling generally passes quickly. If you are having a blood test as part of the first trimester screening, you may feel a slight pinch from the needle.
There is minimal preparation necessary for a nuchal translucency screening. Your healthcare team will likely ask you to drink 2 to 3 glasses of water and not urinate an hour before your ultrasound. Your full bladder helps the ultrasound technician or doctor get the best images.
Questions to ask your doctor
Preparing for a prenatal test like the nuchal translucency screening can be stressful. It is common for patients to forget some of their questions during a doctor’s office visit. You may also think of other questions after your appointment. Contact your doctor with concerns and questions before the nuchal translucency screening and between appointments.
It is also a good idea to bring a list of questions to your appointment. Questions can include:
Why do I need a nuchal translucency screening? Are there any other options for screening?
Are there any special concerns relevant to my case?
How long will the procedure take? When can I go home?
What kind of restrictions will I have after the procedure? When can I expect to return to work and other activities?
Will I need a ride home?
When should I follow up with you?
How should I contact you? Ask for numbers to call during and after regular hours.
When and how will I receive the results of my test?
What other tests or treatments might I need?
Knowing what to expect after a nuchal translucency screening can help you get back to your everyday life as soon as possible.
How will I feel after the ultrasound and when can I go home?
You should not have any pain or discomfort after the ultrasound. Tell a member of your care team right away if you feel any pain or discomfort because it can be a sign of a complication.
You should be able to go home immediately after the screening. You will be able to return to your normal activities, including driving and working.
In some cases, your doctor or technician will discuss the results with you right after the screening test. If you had a blood test, your doctor’s office may call you with the combined first trimester screening results within a couple of weeks.
When should I call my doctor?
It’s important to keep your follow-up appointments after a nuchal translucency screening. Contact your doctor if you have any concerns between appointments.