NT Scans – Nuchal translucency scans: non-invasive and useful for parents who are concerned about their baby having Down’s syndrome
Nuchal translucency scans: non-invasive and useful for parents
There are many tests women undergo during their pregnancy such as blood tests and ultrasound baby scans. Each of these tests take place at different times during the pregnancy and each will look at different factors in order to determine the health of the developing foetus. One of the many scans a woman may be asked to undergo during her pregnancy is the nuchal translucency scan (NT) also known as nuchal scan which measures the risk of the baby having Edward’s syndrome, Down’s syndrome, Patau’s syndrome and Turner’s syndrome.
Each of these conditions are caused by chromosomal abnormalities with Down’s syndrome (trisomy 21) being most common. Children born with Down’s syndrome usually have mild learning disabilities, congenital heart defects, start the process of dementia early (usually by age 40), are prone to chest infections and are increased risk of obesity and breathing problems like sleep apnea. Knowing whether your child is likely to have a chromosomal abnormality can help you to plan for the future.
Women of any age can give birth to a baby with Down’s syndrome however as this risk increases with maternal age the nuchal translucency scan is offered to women over the age of 35. The NT scan is also offered to women who have a family history of chromosomal abnormalities or previous problem pregnancies.
Nuchal scans are non-invasive and do not carry any risk to mother or baby. They are generally carried out between 11 weeks 3 days and 13 weeks 6 days gestation for results to be most accurate. They measure the amount of fluid under the skin in the nuchal fold behind the neck. Fluid levels above 2.9mm are considered high. Women are advised to take someone with them when they go for this test as it can be quite an anxiety provoking experience.
Results are reported as ratios. A result of 1:150 or less indicates an increased likelihood that your baby has a chromosomal abnormality however if you receive a risk result of 1:300 or less you will be asked to consider having a diagnostic test like the Chorionic Villous Sampling (CVS) or amniocentesis which carry a 1-2% risk of miscarriage.
Many women go on to have healthy babies despite receiving risk results of 1:300 or less as results are approximately 75% accurate however when combined with the OSCAR blood test this can improve to 90%. False positive and false negative results are possible in either case.
There are overwhelming odds that your baby will not have Down’s syndrome as only one in every 700 babies born in theUKis born with Down’s syndrome. Families who go on to have a baby with Down’s syndrome need not worry as there are lots of help and support available from other families, forums and organizations such as The Arc, MUMS Parent to Parent, National Down’s Syndrome Society, Down’s Syndrome Association of the UK and Down’s Heart Group. Many babies born with Down’s syndrome leading fulfilling lives.
2d scan pictures often accompany results of the nuchal translucency scan but parents can have 3d ultrasound scans and 4d ultrasound scans later on in the pregnancy.
These scans can be taken at any time during the pregnancy but for more realistic pictures it is best to wait until you are 26 to 32 weeks pregnant so that you can clearly see the baby’s face, fingers, toes, hands and feet as well as any facial gestures that they may be making at the time. There is evidence to suggest that having 3d ultrasound scans and 4d ultrasound scans help with the bonding between parent and baby.
Nuchal translucency or nuchal scans help parents make decisions about their future with their baby as they provide valuable information. When combined with other ultrasound baby scans parents can have a clearer picture of their unborn baby.