I have a great many people contact me to discuss their situation when an increased nuchal translucency (NT) is identified during a scan. Today’s blog is designed to help explain what this is and what it might mean for you and your baby.
As part of the first trimester scan, women in the UK are asked if they want screening for common chromosomal differences such as Down’s syndrome. The usual test is called the “combined test”, which takes several bits of information about you and your baby to estimate how likely it is that your baby is affected by one of the conditions being tested for.
What is nuchal translucency?
One of the measurements used is the size of a collection of fluid under the skin at the back of the baby’s neck. This measurement is called the NT or nuchal measurement. Currently, a measurement of 3.5mm or more is considered to be an increased nuchal translucency (NT). What is “normal” varies quite widely, but an increased nuchal translucency (NT) can be an indication of chromosomal or genetic issues or a cardiac issue. Obviously it is challenging to measure this accurately and so in the NHS there is a requirement that the sonographer or doctor making this assessment has been trained and assessed as competent and reliable in this assessment. It is important to remember that this is a collection of fluid and therefore the measurement can, and does, change day to day. This means that if you have a second option scan it is quite likely that the NT will found to be a different size. However, once an increased measurement has been obtained it should not be ignored in favour of a subsequent lower measurement.The higher the measurement, the more likely it is that it is of significance.
An increased nuchal translucency (NT) makes it very likely that the combined test will be reported as “screen positive” – meaning a higher chance of Down’s, Edward’s or Patau’s syndromes. When considering if you want additional follow up testing, it is important to remember that NIPT (non-invasive testing) is limited to looking for these same three conditions. An increased nuchal translucency (NT) can be due to other chromosomal or genetic issues, which would be missed by NIPT. Too often I have met people who have had NIPT and believed that low chance meant that chromosomal or genetic issues had been ruled out. This is simply wrong. Invasive testing, CVS or amniocentesis, should therefore be discussed and considered. Many people are very reluctant to have this type of testing because they are aware of the associated miscarriage risk. It is very important that you discuss your specific situation with someone who has specialist knowledge in about these results and your options. Most midwives and doctors do not have the level of specialist knowledge needed to give you complete information, so ask to speak to a specialist. You need time with a specialist who will explain the various issues and who will respect what is of greatest concern to you. Someone who will be honest and straightforward with you. Someone you can trust, and who is willing and able to have the very difficult conversations with you about “what if….”.
Cardiac issues are usually best investigated by a very specialist scan review by a fetal cardiac specialist. In most cases you will need to be at least 16-18 weeks pregnant for the structure of the heart to be able to be examined. Whether or not you have testing for chromosomal/genetic issues, this should be offered. Cardiac issues range from variations in structure which cause no problem to your child to very major structural problems which are life threatening. In most cases, early identification of a cardiac issue allows for planning and extra care to give your baby a good future. Click here for more information about cardiac issues associated with increased nuchal translucency (NT). Where life threatening problems are found you need an expert to guide and support you as you seek to work out what this means for you and your baby.
Support for you
Situations like this are extremely difficult to cope with. The uncertainty, the waiting, working out who you can ask your many questions. The service I offer is designed to complement the best of NHS services. I can give you the time and expert advice which you need and can act as your advocate, working to access the best possible care in. I can visit you at home in Surrey or Sussex (on occasions I also go further afield) to provide you with the time you need in a safe and comfortable place, at a time that fits in with the other demands on your time. The initial phone consultation is free, and without obligation, so please get in touch and find out how I can help you.
One off consultations and packages of care are available.