Table of ContentsView AllTable of ContentsPurposePreparationRealiabilityFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Purpose
Preparation
Realiability
Frequently Asked Questions
This test differs from a routine ultrasound and is not offered at every healthcare facility. Rather, it generally must be scheduled at a university medical center or another specialized facility.
When the results of the nuchal translucency screening are positive, there is cause for concern, but it does not necessarily indicate a congenital defect is present. Rather, other diagnostic tests may be needed—such as amniocentesis (an evaluation of the fluid in the amniotic sac that surrounds the fetus) or chorionic villus sampling (a test for serious chromosome disorders).
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NTs are conducted to assess the nuchal folds on the back of the fetus’s neck. By measuring the thickness of the nuchal folds—an indicator of how much fluid there is inside the folds—the risk of possible issues with the fetus, including Down syndrome, can be detected.
Ultrasound Preparation
Before the ultrasound, it’s usually advised for the mother to have a full bladder. This enhances the movement of sound waves in the abdomen, allowing the technician a clearer view of the structures. The nuchal translucency ultrasound may be performed:
Test Results
Combined first-trimester screening—including the ultrasound, a PAPP-A, and an hCG test—does not enable the healthcare provider to make a diagnosis of Down syndrome. Rather, information is gathered to come up with a probability factor that can indicate whether there is a risk of chromosomal disorders or provide reassurance that the fetus is at low risk for these defects.
Information collected includes:
Calculating RiskA specific mathematical calculation will be employed to consider the outcome of the nuchal translucency screening, together with the results of the maternal PAPP-A and hCG blood tests.A numeric risk (including the probability factor) will be assigned. If the numeric probably is one in 230 or higher, it’s considered a positive screen.
Calculating Risk
A specific mathematical calculation will be employed to consider the outcome of the nuchal translucency screening, together with the results of the maternal PAPP-A and hCG blood tests.A numeric risk (including the probability factor) will be assigned. If the numeric probably is one in 230 or higher, it’s considered a positive screen.
A specific mathematical calculation will be employed to consider the outcome of the nuchal translucency screening, together with the results of the maternal PAPP-A and hCG blood tests.
A numeric risk (including the probability factor) will be assigned. If the numeric probably is one in 230 or higher, it’s considered a positive screen.
If a person has a positive screening, a genetic counselor or clinician is assigned to help interpret what the results mean and to help offer choices about options for further testing.
Screening Reliability
There is an 80% accuracy rate in NT screening. When NT screening is combined with beta hCG and PAPP-A blood tests, that rate increases to 90%.
Recent studies have shown that when these three screening tests are further combined with an examination of the fetal nasal bones, as well as an evaluation of fetal blood flow through certain areas of the heart (ductus venous flow and tricuspid flow), the accuracy rate rises to 95%.
How much does a nuchal translucency test cost?
According to USC Fertility at the Keck School of Medicine, a nuchal translucency ultrasound costs approximately $500.
When is nuchal translucency screening done?
The test is usually performed during the first or early second trimester of pregnancy, between weeks 11 and 13.
How long does a nuchal translucency ultrasound take?
The procedure usually takes between 20 and 40 minutes.
A Word From Verywell
Keep in mind that early screening tests, such as the nuchal translucency screening, do not definitively prove anything. They only indicate that more definitive tests are required before any type of diagnosis can be made.
4 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Fetal Medicine Foundation.Nuchal translucency scan.USC Fertility at the Keck School of Medicine.Testing for Downs’ syndrome and other abnormalities in early pregnancy.Mount Sinai.Nuchal translucency test.Johns Hopkins Medicine.Combined first-trimester nuchal translucency screening.
4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Fetal Medicine Foundation.Nuchal translucency scan.USC Fertility at the Keck School of Medicine.Testing for Downs’ syndrome and other abnormalities in early pregnancy.Mount Sinai.Nuchal translucency test.Johns Hopkins Medicine.Combined first-trimester nuchal translucency screening.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
The Fetal Medicine Foundation.Nuchal translucency scan.USC Fertility at the Keck School of Medicine.Testing for Downs’ syndrome and other abnormalities in early pregnancy.Mount Sinai.Nuchal translucency test.Johns Hopkins Medicine.Combined first-trimester nuchal translucency screening.
The Fetal Medicine Foundation.Nuchal translucency scan.
USC Fertility at the Keck School of Medicine.Testing for Downs’ syndrome and other abnormalities in early pregnancy.
Mount Sinai.Nuchal translucency test.
Johns Hopkins Medicine.Combined first-trimester nuchal translucency screening.
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