Raised Nuchal Translucency

Information

Following our discussion today we are providing you with this leaflet because your baby’s nuchal translucency (NT) is 3.5mm or more.

What is a nuchal translucency?

Every unborn baby has some fluid under the skin at the back of the neck. This fluid is called nuchal translucency (NT). You can see this fluid on the ultrasound scan early in pregnancy. It is part of a baby’s normal development in the womb. If your baby has more fluid than usual, it can sometimes be a sign that they have a health problem. This maybe a physical problem for example a heart problem or a chromosomal problem such as Down’s syndrome.

Why do you measure NT?

All pregnant women in England are offered a screening test to give them information on the chance of their baby having Down’s, Edwards’ and Patau’s syndromes. The test combines the results of a blood test taken from the mother with the measurement of the NT from the baby seen on the scan.

You may have chosen not to have your baby screened for Down’s, Edwards’ and Patau’s syndromes however some extra fluid has been noted at the back of your baby’s neck. This extra fluid maybe linked with physical and chromosomal problems, therefore the person doing the scan will tell you if they see more than 3.5mm of fluid at the back of your baby’s neck.

What is a normal NT measurement?

We cannot give you a normal figure, because the NT usually grows in proportion with your baby. This means that the measurement depends on, amongst other things, how many weeks pregnant you are when you have your scan. However we do know that if the NT is 3.5mm or more, early in the pregnancy, there is a greater chance that your baby will have a physical problem or chromosomal condition. In addition we know that the thicker the NT the more likely the baby is to have a heart problem and that thickened NT measurements can be seen in a variety of genetic disorders.

It is important to remember that many babies who have a thicker NT measurement at the early scan are born healthy and well.

If my baby’s NT is above 3.5mm will I be offered further tests?

We will offer you an appointment with a specialist to discuss what this may mean for your baby. The specialist will offer you an invasive test such as a Chorion Villus Sampling (CVS) or Amniocentesis.

At 19-20 weeks gestation you will be offered a detailed ultrasound scan when we will check your baby to see if we can find any evidence of a physical problem. In addition, we will offer you a fetal cardiology scan to check the baby’s heart as they are the experts at picking up subtle heart defects.

If the chromosome test is normal, the anatomy and heart scans are normal then we will be very reassured. However, it must be remembered that not all problems can be seen on ultrasound.

What are my options?

The options are always to continue with the pregnancy, with or without the additional testing described above. If you choose to have the tests and there is a problem with your baby, you will be supported to make the choice that is right for you and your family. Some women/couples will consider a termination, which is an option either at the time of diagnosis or later in pregnancy.

Contact

Please telephone the Antenatal and Newborn Screening Co-ordinator on 01274 364295 if you have any questions and/or would like to discuss this further. If there is no one available please leave a message on the answer machine leaving your name and phone number.