Genetic ultrasound

Genetic ultrasound – when should it be performed?

Genetic ultrasound is also called first trimester ultrasound. The name comes from the fact that the main focus of the examination is to detect possible genetic defects, among other things. The ultrasound examination is carried out between the 11th and 14th week of pregnancy. The genetic ultrasound is one of the obligatory ultrasound examinations during pregnancy, along with the mid-trimester ultrasound (2nd trimester), the 3rd trimester ultrasound and the ultrasound at the time of delivery.

First trimester ultrasound should not be abandoned in favour of the increasingly popular fetal DNA tests. According to current recommendations, NIPTs are recommended in cases of suspected genetic defects or in cases of intermediate risk in a composite test. Genetic ultrasound plays a very important role in diagnosis in early pregnancy.

Genetic ultrasound – what does it examine?

During genetic ultrasound, the gynaecologist assesses the position of the pregnancy, its viability, the anatomy of the foetus and calculates the risk of chromosomal abnormalities and pre-eclampsia in a so-called combined test (which includes biochemistry as well as ultrasound). The age of pregnancy is also determined. If the calculated due date differs from the date of the last menstrual period by 7 days or more, it becomes the relevant date until the end of the pregnancy. It should not be changed during later ultrasound examinations.

An important part of genetic ultrasound is the assessment of nuchal translucency. An abnormal image can be associated with diseases such as Down syndrome. To make the risk assessment more accurate, the mother’s medical history and blood parameters such as free beta-hCG, PAPP-A and PlGF should be taken into account in addition to nuchal translucency.