Ioannis Raptis gained extensive clinical experience while serving as a Senior Consultant at the German Perinatal Centre AKH Hagen. During his tenure, he completed comprehensive training in Specialised Obstetrics and Perinatal Medicine (Spezielle Geburtshilfe und Perinatalmedizin), with a particular focus on the management of high-risk pregnancies and complicated deliveries.
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Nuchal translucency (NT), also known as the first-trimester or Level I ultrasound, is a specialised ultrasound examination performed towards the end of the first trimester of pregnancy. During the examination, the doctor measures the amount of fluid accumulated at the back of the fetal neck.
This examination helps estimate the likelihood of three chromosomal conditions in the fetus: Down syndrome (trisomy 21), Patau syndrome (trisomy 13), and Edwards syndrome (trisomy 18). At the same time, it provides valuable information about fetal anatomy and the risk of certain complications developing during pregnancy.
The nuchal translucency scan is performed between 11 and 14 weeks of gestation. During this period, the fetal crown-rump length (CRL) is between 45 mm and 84 mm.
Nuchal translucency is a screening test. This means that the examination cannot establish or rule out a diagnosis with 100% certainty.
Its primary purpose is to estimate the risk of a chromosomal abnormality in the fetus, while also providing an initial assessment of fetal anatomy.
More specifically, the examination helps:
Risk assessment is based on a combination of ultrasound findings and the maternal serum biochemical markers PAPP-A and free β-hCG (fβ-hCG). Maternal characteristics, including age, weight, height and ethnicity, are also taken into consideration.
The nuchal translucency scan is recommended for all pregnant women and is performed when the fetal crown-rump length (CRL) is between 45 and 84 mm.
It is important to emphasise that alternative methods of prenatal screening or diagnosis, such as NIPT, amniocentesis or chorionic villus sampling (CVS), do not replace the need for a nuchal translucency scan. This is because the examination also provides valuable information regarding fetal growth and anatomy.
A nuchal translucency scan does not require any special preparation. It is advisable to have a light meal and drink sufficient water before the examination to facilitate ultrasound imaging.
It is also helpful to allow sufficient time for the examination, as obtaining the appropriate ultrasound views may occasionally take longer depending on the fetal position.
The nuchal translucency scan is a painless ultrasound examination that usually takes approximately 20 to 30 minutes. It is generally performed transabdominally. In certain cases, a transvaginal ultrasound may be required to obtain clearer images of the fetus.
During the examination, the obstetrician-gynaecologist precisely measures the amount of fluid located at the back of the fetal neck. A maternal blood sample is also collected to measure specific biochemical markers, including PAPP-A, β-hCG and PlGF. The results are usually available within two to three days, as the final risk assessment also incorporates the biochemical marker levels.
In addition to measuring nuchal translucency, several other ultrasound markers may be assessed to improve the accuracy of chromosomal abnormality risk estimation. These include the presence of the fetal nasal bone, blood flow through the ductus venosus, and blood flow across the tricuspid valve of the fetal heart.
The results of the nuchal translucency scan are expressed as a risk estimate rather than a definitive diagnosis.
In most cases, the results indicate a low risk of chromosomal abnormalities. However, an increased estimated risk does not necessarily mean that the fetus has a chromosomal abnormality. Rather, it indicates that further assessment may be appropriate.
If an increased risk is identified, your obstetrician-gynaecologist will explain the significance of the results in detail. If considered necessary, the available options for additional prenatal testing will be discussed with you. Further testing may include non-invasive prenatal testing (NIPT) or diagnostic procedures such as chorionic villus sampling (CVS) and amniocentesis.
Similarly, the identification of an increased risk of preeclampsia, fetal growth restriction or preterm birth may lead to closer, individualised monitoring throughout pregnancy and, where indicated, the timely implementation of preventive measures aimed at reducing the risk of these complications.
For specialised guidance and support throughout every stage of pregnancy, Obstetrician-Gynaecologist Ioannis Raptis and his team are at your disposal. Contact us to arrange your appointment.
