The nuchal translucency scan (also called the NT scan) uses ultrasound to assess your developing baby's risk of having Down syndrome (DS) and some other chromosomal abnormalities, as well as major congenital heart problems.The NT scan measures the clear (translucent) space in the tissue at the back of your baby's neck.
The screening is widely available, but because it requires special training and equipment, not all healthcare providers provide it.(Women who are at high risk for carrying a child with Down syndrome or are 35 or older may be offered cell-free DNA testing, which can be done as early as 10 weeks.
Your dating scan or 12 weeks scan is your first ultrasound scan, and is used to predict the due date of your baby as well as help to ensure the foetus is developing normally and determine exactly how many babies you have in there!
Although the scan is often referred to as "your 12 week scan" the recommendations from NICE are that it should occur when you are between 10 and 14 weeks pregnant.
Logistically its unlikely to happen exactly at 12 weeks so don't worry if its a little later or earlier than this.
The scan is primarily used to predict your due date and is more accurate than other methods.
You may have already estimated your due date from the first day of your your last menstrual period (LMP) - this is even though you don't actually conceive until 14 days after your LMP, or later than this if your cycle is longer than 28 days.You probably know when your LMP was, but not when you actually conceived.If no nasal bone is seen in the developing baby, some experts believe this increases the likelihood of chromosomal abnormalities.)Like other screening tests, an NT scan won't give you a diagnosis.The scan can only assess your baby's risk for certain problems and help you decide whether to have chorionic villus sampling (CVS) or amniocentesis to find out whether your baby is actually affected.You can also wait and combine the results with second trimester screening results for more information about your baby's risk before you decide whether to proceed with an amnio.The NT scan is offered to all pregnant women in the first trimester.