Prenatal diagnosis is a complex of diagnostic measures aimed at detection of the fetus development anomalies of chromosome and non-chromosome ethiology. The method is a combination of US examination of the fetus and the biochemical analysis of the pregnant woman’s blood.
“Astraia” is the single international program of prenatal diagnosis of the fetus chromosome pathology which computes the individual genetic risk with 90-95% probability.
Biochemical screening (PAPP-A and b-HCG) is performed with the use of KRYPTOR analyzer which is a closed-type equipment that completely excludes the impact of a human factor on the result of the analysis.
In “Gameta” Medical Centre ultrasonic examination is accomplished by ultrasonic medical specialists licensed for such examinations by FMF (Fetal Medicine Foundation) of Great Britain. The license is confirmed and renewed annually after passing the examination in the FMF only.
US examinations are performed with the use of US units of expert class manufactured in 2016 only. Additionally, the risk of pregnancy complications is assessed (pre-eclampsia, premature delivery, fetus development retardation syndrome) with due account of the anamnesis, biochemical markers and blood circulation in the uterine arteries indications.
Screening in the first trimester is made within strictly defined periods (11 weeks 2 days – 13 weeks 6 days at crown rump length of the fetus equal to 45-82 mm), it is impossible to correctly determine echo-markers in the earlier gestation period.
High risks detected during the prenatal screening of the first trimester do not always mean that the fetus has chromosomal abnormalities. In order to make the final diagnosis, the patient has to pass medical and genetic consulting and determine the karyotype of the fetus with the aid of invasive prenatal diagnosis of amniocentesis.
2nd trimester of pregnancy
Pregnant women who have passed the combined prenatal ultrasonic and biochemical screening in the 1st trimester and did not fall in the high risk group of the fetus chromosome pathology are further examined during 18-21 weeks in order to check for congenital abnormalities of the fetus pertaining to non-chromosome ethiology. US-test is made and analysis of only one biological marker – alpha-fetoprotein – is accomplished.
If the pregnant woman was not examined in the 1st trimester or if she fell in the intermediate risk group, it is necessary to make analyses with three biological markers (alpha fetoprotein, beta-HCG and unconjugated estriol) during 17-20 weeks and calculate the risk of the chromosome pathology of the fetus.