How much nuchal translucency in the fetus is normal?

The article was professionally consulted by Specialist Doctor I Le Hong Lien - Department of Obstetrics and Gynecology - Vinmec Central Park International General Hospital.

Nuchal translucency measurement is an extremely important test, helping doctors diagnose the risk of Down syndrome in the fetus from the first stages of pregnancy. During pregnancy, pregnant women need to have antenatal check-ups according to the doctor's regular schedule to control the mother's health status and the comprehensive development of the fetus. Measuring nuchal translucency helps mothers feel secure about the health of the fetus.

The accumulation of fluid in the skin on the back of the baby's neck is called nuchal translucency. Nuchal translucency is an indicator used to assess the risk of a fetus having Down syndrome and other birth defects.

Nuchal translucency measurement is the method used to diagnose Down syndrome early in pregnancy. Fetal ultrasound at the right time is a way to check the nape of the fetus, this helps doctors to diagnose the risk of the fetus having Down syndrome or not.
Based on the results of the nuchal translucency measurement, it not only helps the doctor diagnose the risk of Down syndrome in the child, but also helps the doctor detect whether the child has a chromosomal abnormality or not.
All healthy babies have fluid on the back of their necks, but normal babies will have less fluid under the skin at the back of their necks than babies likely to have Down syndrome.
When determining the fetus at risk of Down syndrome, the doctor will conduct follow-up tests such as chorionic villus sampling, amniocentesis ....to accurately determine whether the baby has Down syndrome. or not.
The thicker the nape of the neck, the higher the risk of malformations because of chromosomal abnormalities and accompanying other abnormalities in body structure. However, to get the most accurate nuchal translucency result, it is necessary to perform nuchal translucency measurement at the right time.

To get the most accurate nuchal translucency measurement, the measurement should be performed between 11 and 13 weeks of pregnancy. This is an extremely important milestone, which pregnant women absolutely must pay attention to.
For fetuses less than 11 weeks old, the fetus is still too small, the nape of the neck is still fuzzy, so it is impossible to get accurate results when measuring nuchal translucency, therefore, all diagnoses in This time period cannot be exact.
For fetuses over 14 weeks old, the nuchal translucency at this time has returned to normal, therefore, the test is no longer meaningful, the doctor cannot give any any accurate diagnosis or assessment of the fetal condition.

After the ultrasound is conducted, the doctor will tell the pregnant woman the results of the nuchal translucency. For babies with a size of 45-84mm, the normal nuchal translucency will be less than 3.5mm. Usually, the results of the nuchal translucency test will help the doctor diagnose a 75% chance of having a baby with Down syndrome.
For an 11-week-old fetus, the standard nuchal translucency is 2mm. For a 12-week-old fetus, the standard nuchal translucency is usually less than 2.5mm. For a 13-week-old fetus, the standard nuchal translucency is 2.8mm. The risk of Down syndrome is low for fetuses with nuchal translucency less than 1.3mm.
If the nuchal translucency is greater than 3mm, the risk of fetal Down syndrome is quite high. If the nuchal translucency is 6mm, then the fetus has a high risk of Down syndrome and other birth defects. A nuchal translucency of 3.2-3.5mm is called thickening and increases the risk of chromosomal mutations. The cases of fetus with nuchal translucency of 2.9mm, although not a high level, can affect the value of screening test in the first 3 months, so to be sure, should perform show more in-depth tests. The amount of fluid that accumulates in the neck area increases, causing the nuchal translucency to increase. Therefore, the most effective method to check and diagnose fetal malformations in the first 3 months of pregnancy is ultrasound measurement of nuchal translucency. The higher the risk of malformations, the higher the nuchal translucency is accompanied by other structural abnormalities. In addition to regular monitoring and full implementation of prenatal screening tests, pregnant women should also be fully vaccinated with vaccines for pregnant women to protect the health of mother and baby.

The nuchal translucency index is the basis for assessing the risk of Down's disease and some other birth defects, so this index is very important. The accuracy of nuchal translucency depends on the ultrasound equipment and the qualifications of the technician and doctor.
Vinmec International General Hospital is a high-quality medical facility that is highly appreciated by customers for its quality of examination and treatment as well as professional services. Vinmec has the most modern equipment system, with the most advanced ultrasound machines in the world and a team of experienced obstetricians in prenatal diagnosis and intervention to help monitor and detect early birth defects.
In addition, to protect the health of mother and baby comprehensively, Vinmec offers a variety of package Maternity services. With this package, pregnant women will have regular antenatal check-ups with specialist doctors, especially thyroid screening tests for mothers in the first 3 months, Rubella tests. Perform prenatal and postnatal screening tests for the baby. During pregnancy, if a pregnant woman encounters any abnormal health problems, she will be consulted and treated by a specialist doctor. After each visit, the doctors will analyze the ultrasound and test results and advise on health care, nutrition, and rest suitable for each pregnant woman, helping the mother and fetus to be healthy. well developed, uniform indicators.