PRENATAL BIOCHEMICAL SCREENING
Double test and placental growth factor (PlGF)
What is prenatal biochemical screening?
Prenatal biochemical screening is a simple blood test intended for every pregnant woman, to measure the level of certain protein compounds of placental origin in the maternal serum.
The concentrations of the biochemical markers are converted toMoMs (Multiple of Median). The equivalent MoM of a certain marker is computed by dividing the value measured at the value of the median corresponding to the pregnancy age, a value which is specific for the population, conception method, mother’s weight, and smoking status.
By combining these values with the ultrasound measurements and with the maternal age risk using a certified statistics program we can assess the final risk of having a child with Down, Edwards, or Patau syndrome.
How can the preeclampsia risk be evaluated?
Three biochemical markers are being measured during the second trimester of pregnancy (weeks 14+1-21+6): Free β-hCG (Free β-human Corionic Gonadotropin), AFP (α-fetoprotein), and µΕ3 (Free Estriol).
Where can I have these tests done?
1. The biochemical markers must be measured in a laboratory using FMF-certified analysersF
2. The ultrasound examination must be performed by doctors specialized in maternal and foetal medicine
3. The risk must be computed using a certified software
CytoGenomic Laboratory was the first laboratory in Romania to have introduced this advanced screening method in 2010.
Although prenatal biochemical screening can be performed both during the first (as double test), and the second trimester of pregnancy (triple test), over the last years the outcomes of the studies done “shifted” screening towards the first trimester of pregnancy.
The biochemical results of the first trimester of pregnancy associated with the ultrasound parameters: NT (Fetal Nuchal Translucency Thickness), the measurement of the nasal bone, CRL (Crown-Rump Length), and with the maternal age lead to a detection rate of around 95%, with 5% falsely positive results, which are better than those from the second trimester screening.
Recent studies showed that the optimal period for collecting and measuring biochemical markers for the double test starts in the 10th week of pregnancy, while the optimal period for ultrasound measurements is between the 12thand the 13th week of pregnancy.
An optimal risk assessment can be obtained if the information about the pregnancy is accurate and the biochemical markersand Nuchal Translucenc ymeasurements have been performed using a highly accurate technique. The BRAHMS KRYPTOR Immunoanalyzer meets these requirements.
Screeningul prenatal din serul matern este un test prognostic care evaluează riscul pentru sindrom Down și alte sindroame cromozomiale în cazul fiecărei femei gravide, așadar nu există rezultat “fără risc”!
A low risk result does not exclude a maternal and foetal pathology.
In high-risk cases, additional tests can be required to further asses the foetus.