Everything You Need to Know About Nuchal translucency Scans
A Nuchal translucency scan is a part of every pregnancy, and it is an important test for a variety of reasons. Learn about how it’s done, why it’s done, and why you should have it done.
Nuchal translucency (NT) is a measurement of the fluid-filled space at the back of a developing fetus’ neck. The measurement is typically taken during the first trimester of pregnancy, between 11 and 14 weeks.
The NT scan is a non-invasive test that uses ultrasound technology to measure the thickness of the fluid-filled area at the back of the fetus’ neck. This measurement is used to assess the risk of chromosomal abnormalities, such as Down syndrome, in the developing fetus.
The NT scan is typically performed in combination with a blood test, known as a maternal serum screening test, to provide a more accurate assessment of the fetus’ risk of chromosomal abnormalities.
The NT scan is generally considered to be a very safe test, with no known risks to the mother or the developing fetus. However, it is important to note that the NT scan is not a diagnostic test and a positive result does not confirm the presence of a chromosomal abnormality. A diagnostic test, such as chorionic villus sampling (CVS) or amniocentesis, is required for a definitive diagnosis.
It is important to note that the NT scan is not a mandatory test, and the decision to have the scan is ultimately up to the parents. However, it is important for parents to be fully informed about the potential benefits and limitations of the test before making a decision.
What Is Maternal Serum Screening?
A maternal serum screening test, also known as a “triple screen” or “quad screen,” is a blood test that is often performed in combination with the nuchal translucency (NT) scan during the first trimester of pregnancy. The test measures the levels of certain proteins and hormones in the mother’s blood that are associated with chromosomal abnormalities, such as Down syndrome, in the developing fetus.
The triple screen test measures the levels of three specific substances in the mother’s blood: alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and estriol (uE3). The quad screen test is similar, but also includes the measurement of inhibin-A.
The levels of these substances are compared to a reference range based on the mother’s age and gestational age. If the levels of one or more of these substances are outside of the reference range, it may indicate an increased risk of chromosomal abnormalities.
It is important to note that a positive result on the maternal serum screening test does not confirm the presence of a chromosomal abnormality, but rather indicates an increased risk that requires further diagnostic testing, such as chorionic villus sampling (CVS) or amniocentesis, to confirm the diagnosis.
A maternal serum screening test is usually done between 15-20 weeks of pregnancy and it is also done along with ultrasound, which is called integrated screen or sequential screen. It is not a mandatory test and the decision to have the test is ultimately up to the parents, but it is important for parents to be fully informed about the potential benefits and limitations of the test before making a decision.
In conclusion, a maternal serum screening test is a blood test that is often performed during the first trimester of pregnancy, it measures the levels of certain proteins and hormones in the mother’s blood that are associated with chromosomal abnormalities. It is usually done between 15-20 weeks of pregnancy and is often done along with ultrasound, it is not a diagnostic test and positive results does not confirm the presence of chromosomal abnormalities but it indicates an increased risk that requires further diagnostic testing, it is important for parents to be fully informed about the potential benefits and limitations of the test before making a decision.
What Chromosomal Abnormalities Does This Test Look For?
The nuchal translucency (NT) scan is primarily used to assess the risk of chromosomal abnormalities in the developing fetus, specifically Down syndrome (trisomy 21), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome). These are all chromosomal conditions caused by an extra copy of a specific chromosome.
Down syndrome is the most common chromosomal abnormality and is caused by an extra copy of chromosome 21. It is characterized by physical and intellectual developmental delays, and can also result in certain medical conditions such as congenital heart defects.
Trisomy 18 (Edwards syndrome) is a less common chromosomal abnormality, caused by an extra copy of chromosome 18. It is associated with severe intellectual and physical developmental delays, and many infants born with this condition do not survive past the first year of life.
Trisomy 13 (Patau syndrome) is another rare chromosomal abnormality, caused by an extra copy of chromosome 13. It is associated with severe intellectual and physical developmental delays and multiple birth defects, such as cleft lip and palate, heart defects, and brain and eye abnormalities.
Other chromosomal abnormalities that can be identified by the NT scan are Turner syndrome, which is caused by a missing X chromosome, and Triploidy, which is caused by an extra set of chromosomes.
It is important to note that the NT scan, when combined with a maternal serum screening test, is not a diagnostic test and cannot confirm the presence of a chromosomal abnormality. It is only used to assess the risk and further diagnostic testing, such as chorionic villus sampling (CVS) or amniocentesis, is required for a definitive diagnosis.
In conclusion, Nuchal Translucency (NT) scan is primarily used to assess the risk of chromosomal abnormalities in the developing fetus. It is important to note that the NT scan, when combined with a maternal serum screening test, is not a diagnostic test and cannot confirm the presence of a chromosomal abnormality.
Katie Reed is a passionate writer and mother of four vivacious boys from Salt Lake City, Utah. Drawing from her own journey through TTC, pregnancy, and the joys of raising children, she offers a wealth of insight into the world of motherhood. Beyond her heartfelt tales, Katie delights her readers with family-friendly recipes, engaging crafts, and a curated library of printables for both kids and adults. When she’s not penning her experiences, you’ll find her crafting memories with her husband and sons—Dexter, Daniel, Chester, and Wilder.
