Screening is a simple and accessible examination which can detect the possibility (risk) of a condition even before symptoms occur.
Prenatal screening focuses on the detection of serious foetal defects which mostly develop randomly as a” genetic accident “at conception or in the first weeks of pregnancy. Down Syndrome is an example of the defects that we can identify with this approach.
Based on the results of scientific studies and our experience we recommend:
- At the prenatal consultation, the mother is informed about the possibility of the screening of congenital defects. A Genetic consultation is recommended for all mothers over the age of 35 at the time of the expected delivery date.
- In week 10 a blood sample will be taken from the mother in order to identify the presence of important pregnancy proteins (plasma protein A - PAPP-A) and hormones (free beta-subunit of human chorionic gonadotropin - FB-hCG).
- In week 12 nuchal translucency (NT) is measured by means of ultrasound and the presence of the nasal bone (NB) of the foetus is determined. If necessary, further ultrasonic features of the foetus are examined (such as blood flow in the vessels of the mother and the foetus). Results of the blood testing from week 10 and of the ultrasound examination are combined and the risk of a congenital defect is determined. Mothers with a positive combined result are advised to have a consultation in a specialist prenatal diagnosis centre or early pregnancy unit, for further direction. We expect that 2% of women will have a combined positive result.
- If a negative test is obtained in week 10 a second blood test is taken during week 14 - 17. This test will identify any further presence of significant markers (alpha-fetoprotein - AFP, chorionic gonadotropin -T-hCG and unconjugated estriol - uE3) to enable the clinical team to calculate the integrated risk of a congenital defect occurring. The results from all the tests are compared (that means PAPP-A, NT, NB from week 10 and 12 and AFP, T-hCG, uE3 from the second blood sample). We expect that an additional 2% of examined women will have an integrated positive result of the screening. Mothers with a positive integrated result are advised to have a consultation in a specialist prenatal diagnosis centre or early pregnancy unit, for further direction.
- The screening is completed with an ultrasound examination in week 20.
We recommend prenatal testing of pregnant women who are over 35 years of age and when the male partner is over 45 years. The risk of the emergence of genetic defects in the offspring rises with the increasing age of the parents.