The screening can be performed between 11+0 and 13+6 weeks, with the optimal period being after the 12-th week, as the size of the foetus allows a more detailed view of the organs.
Screening is a risk assessment for congenital anomalies of the foetus and includes ultrasound examination, nuchal translucency measurement, biochemical testing (by venous blood sampling).
What you should bear in mind before coming for screening
If your pregnancy is achieved through fertility treatment, you should know the date of the egg retrieval, even if you had a frozen transfer, as this is important for dating the pregnancy as well as calculating the risk for chromosomal disorders (transferring embryos frozen 2 years ago reduces the risk for chromosomal disorders to the degree of risk for the woman at the time of the egg retrieval).
You should find out if there are any inherited diseases in the family – for instance, if there are children born with malformations who died soon after birth, and it is important to know the type of malformation. If you have medical history available, it is advisable to bring it with you on the day of the examination.
If you have any previous diseases or co-morbidities, it is advisable to bring the relevant documents and medical history records.
If you have undergone testing in another center to assess the risk of chromosomal disorders, it is advisable that you submit the written conclusion of the specialists.
You should inform yourself whether your first-degree relatives (mother, sister) had pre-eclampsia during pregnancy.
If you have undergone surgery, especially for malignant diseases, take the relevant medical history records with you, and the pathological report, if possible.
IMPORTANT! On the day of the examination, it is advisable to arrive at least 5 minutes early at the consulting room where the examination will be carried out so that you have the opportunity to read the informed consent form and sign it before the examination.
About the screening
The examination can be performed between the 10-th and the 12-th gestational week.
State-of-the-art technology allows experienced specialists, with a targeted examination, to recognize about 55-60% of foetal diseases and malformations even at this early stage of pregnancy.
An important part of screening in the first trimester of pregnancy is the NT – nuchal translucency test.
Normal nuchal translucency is an expression of low risk for foetal chromosomal abnormalities. This risk can be calculated based on the combination of maternal age, NT thickness and gestational age.
The calculation of an individual’s risk for a foetal chromosomal abnormality is performed by using software provided by FMF London, and for this purpose it is necessary for the doctors calculating the risk to be pre-certified with FMF London.
Certification presumes excellent physician skills, and is carried out by FMF specialists, following the strictest criteria. For greater accuracy, the β-HCG and PAPP-A hormone values are included in the risk calculation.
Additional markers of chromosomal abnormalities, such as the presence or absence of a nasal ossicle, tricuspid valve insufficiency, and the shape of the blood flow of a vessel located close to the heart, the ductus venosus, are also examined and taken into consideration when assessing the risk of chromosomal abnormality.
The risk calculated using this method is most often lower than the risk of miscarriage after an invasive procedure even for pregnant women over 35 years of age and should therefore be offered to expectant mothers prior to recommending any invasive diagnosis.
Combining all the examined factors allows the detection of 90% of Down syndrome cases.
It is important to know that a thickened nuchal translucency may be an expression of other foetal malformations, such as a heart defect, but does not necessarily prove a disease or chromosomal abnormality. A thickened nuchal fold is only an expression of a statistically increased risk for chromosomal abnormalities as compared with cases in which a nuchal fold of normal thickness is found.
It is important to complement the foetal examination in the first trimester with the so-called “Anomally scan” in the 20-th-22-nd gestational week.
The assessment of feto-placental circulation by means of Doppler provides important information about the condition of the foetus and the function of the placenta and allows the prenatal specialist to predict the course of the pregnancy to a certain extent and to plan your visits to achieve maximum safety for you and your baby. Doppler testing is performed at each of your appointments in the Prenatal Diagnostics and Therapy Department.
Ultrasound and the use of Doppler are not harmful or stressful to the foetus.