This is a very important exam for fetuses and mothers since it is the one that detects possible abnormalities in babies such as Down syndrome, Patau syndrome, Edwards syndrome, and many other problems that could happen at conception.
When is the Exam Done?
It can be performed from the 11th week up to the 13th, but it is usually done in the 12th week when doctors believe it is most effective for identifying significant abnormalities. The exam consists of measuring the fetal nuchal fold (the skin at the nape of the neck) and checking for the presence of the nasal bone1.
Exam Results
The normal range for the exam is determined by each laboratory where the test is conducted, but there is a limit for it to be considered normal, or a risk zone. The limit considered normal is 2.5 mm, above which is considered a risk zone.
But if you had the exam and a value higher than this was detected, it does not necessarily mean your baby has a problem. A number of factors need to be identified for the diagnosis to be confirmed. For example, in Down syndrome, if the result is 5 and the limit is 2.5, it is very likely that your prenatal doctor will request further tests.
Other Important Exams During Pregnancy
The amniocentesis test2 consists of withdrawing a small amount of amniotic fluid so a fetal karyotype test (checking the number of chromosomes) can be performed.
This exam is cautiously recommended by doctors, as there is a small risk to both the fetus and the mother, and it is only done with the couple’s consent.
Morphological Ultrasound
Another test that is done, but without risks, is the morphological ultrasound3. This test is performed with more criteria, and I will talk about it in more detail later since it’s such a complex and important exam.
Remember, if you received an ultrasound report saying that your baby’s nuchal fold is greater than 2.5, do not panic. In order to diagnose any syndrome, a combination of factors is necessary. I myself have seen and heard of many cases where this measurement did not mean anything about syndromes. Just talk to your doctor, and they will tell you whether it is worth the risk of amniocentesis.
Kisses and see you soon!
See also: Ultrasound During Pregnancy – When to Do It and Its Importance
