If you are pregnant and in between 10 to 14 weeks of gestation, it’s time to submit yourself to one of the pregnancy tests which is known as the nuchal translucency scan (NT scan). It’s to measure the nuchal fold which is a normal skinfold situated at the back of your baby’s neck while you are at the end of the first trimester or the start of the second trimester.
To put it simply, your doctor will measure the thickness of clear space located at the back of the neck of your fetus to determine whether they are at risk of developing defects related to chromosomal abnormalities such as Down syndrome, Patau syndrome and Edward’s syndrome. Knowing your NT scan result can give you a peace of your mind or prepare you for what’s to come.
How does it work?
In Malaysia, the overall incidence rate of Down Syndrome is 1 in 800 births. The risk increased proportionally to the mother’s age and it’s considered one of the most common genetic conditions. The other two are rare and often fatal in their first year of life. If there are some abnormalities during the cell division, depending on which pair of chromosomes were affected, they can be afflicted by one of those diseases.
During the NT scan, apart from ultrasound, blood tests will also be taken to measure the level of maternal hormone called human chorionic gonadotropin along with her plasma protein. Both of these parameters can provide a non-specific clue pointing towards the chromosome problem diagnosis.
Your doctor or an operator will conduct an abdominal ultrasound which uses high frequency sound waves which enable us to see what’s happening on the inside. Through this, your baby’s nuchal fold can be measured to predict the risk of chromosomal abnormalities potentially lies dormant, ready to surprise you once they are out and about.
Screening test vs diagnostic test
It’s not easy, especially for a new mother to hear that they have an abnormal NT scan result. What does that mean? Is my child alright? You must be confused and have lots of questions. No worries though. Even if you were told that the result of your NT scan was abnormal or inconclusive, it doesn’t mean your child has chromosomal abnormalities. Know that NT scan only enable us to predict the risk of getting a child with such defects. It’s not diagnostic.
In order to confirm, you have to proceed with a diagnostic test. It’s a test which confirm the presence of condition or disease that has been singled out by your preliminary screening test. There are a variety of options and usually they are quite invasive. Certain tests can only be done at a certain point of time, so ask your doctor about it and be sure to understand the benefits and risks of carrying out such tests.
NT scan might be non-confirming but it is a safe and noninvasive test that do no harm to either you or your baby. There is no harm on submitting for it so talk to your doctor and get tested.