Genetic ambulatory office

Examinations during pregnancy

Prenatal screening

Screening for congenital developmental defects in pregnancy (prenatal screening) is focused on detection of the risk of serious foetal defects, which mostly original randomly as a “genetic accident” in the course of conception or in the first trimester of pregnancy.

The sequence of screening examinations:

With the first visit for pregnancy consulting, the future mother should first get information on the possibilities of screening for congenital developmental defects in terms of the most contemporary medical knowledge. At the same time pregnancy in the mother is confirmed by ultrasound with the determination of its dating.

First part of the screening (the multiple marker combined test):

At 11+0 to 13+6 weeks of pregnancy we carry out the first ultrasound screening examinations, during which we determine the definitive date of pregnancy, assess the complete morphology of the foetus, determine the size of its nuchal translucence (NT), the presence of the nasal bone (NB) of the foetus and other signs (flows in the blood vessels of the mother and the vessels and heart of the foetus). In the given weeks we also carry out blood samples for examination of values of pregnancy-associated plasma protein A (PAPP-A) and free beta sub-units of choriogonadotropin (free ß-hCG).

Results of the first part of the screening:

The risk of a foetus affected by a congenital developmental defect (chromosomal abnormality) is estimated from the combined results of blood and ultrasound tests from the first part of the screening. A mother with a high risk is summoned back to a consultation in our centre, where her doctor recommends an additional optimal approach (e.g. another blood sampling for examination of free DNA (NIPT) or chorionic villus sampling (CVS/) and eventually amniotic fluid(AMC)).

Second part of the screening (morphological – genetic ultrasound):

In the 19th to 22nd weeks of pregnancy we perform morphological ultrasound screening with a focus on detailed examination of possible anomalies of the foetus, examination of the heart of the foetus.

Results of the second part of the screening:

Morphological - genetic ultrasound in the 2nd trimester. Within the scope of detectability we are capable of excluding up to 90% of all structural abnormalities of a foetus and increased detectability for Down Syndrome up to 99% percent.

Historically in the 1970s a border was set for mothers for consideration of prenatal genetic examination of the foetus (sampling of amniotic fluid or chorionic villus sampling ) at 35 years and in men at 45 years old. Prenatal genetic examination for reason of pregnancy of mothers over age 35 and over and in men over 45 at present, with the current above-mentioned possibilities of foetal examination (ultrasound, blood tests), is obsolete, and age should only be a reason for genetic consultation, during which parents decide for the most suitable approach following the development of the foetus.