Biochemical screening (from English "to screen" - sort, sift) is a complex of diagnostic studies aimed at identifying women belonging to a certain risk group. The purpose of this survey is to determine the probability of a child with severe pathological conditions - neural tube closure defects and chromosomal abnormalities.
Biochemical screening is an important component of complex prenatal screening (laboratory and ultrasound studies aimed at detecting malformations of the fetus), which, according to doctors, is absolutely safe and does not adversely affect the pregnancy itself or the fetus , so it is suitable for all future moms. Biochemical screening is carried out in two stages: Screening for the first trimester (from 10 to 14 weeks? double test) and screening for the second trimester (from 16 to 20 weeks? triple test).
What is the basis of biochemical screening?
This procedure is not very simple, but thanks to it you will be convinced that in the genetic program of your future child everything is fine. To carry out the procedure for biochemical screening, it is necessary to pass a blood test, which (with the help of certain markers) is checked for certain types of proteins indicating chromosomal abnormalities. Since the birth of a new life in your body, the placenta immediately begins to produce new substances for you (most often proteins), which after penetration into the circulatory system leave the body.
With a normal pregnancy, as the child develops, the amount of these substances varies. If the fetus has some kind of developmental disability, then, regardless of the causes that caused it, the amount of proteins will differ significantly from the generally accepted norm. It is this process that underlies the method of biochemical screening.
In the first trimester of pregnancy, you can be sent for blood donation and biochemical screening to study the state of hCG only in the body of a future mother, in which only a certain component is of interest to doctors - a special protein in the blood of pregnant women RAPP-A and a free beta subunit. After receiving the results of the analysis, the computer compares them with the norm and determines the diagnosis (if it is detected). Thanks to biochemical screening, early chromosomal abnormalities such as neural tube defects, Edwards syndrome, or Down's syndrome can be detected in early pregnancy.
What can determine biochemical screening for the 2nd trimester (triple test)?
At later dates, other abnormalities in fetal development can be detected using biochemical screening. Under the supervision of doctors are hormones such as estriol and chorionic gonadotropin, as well as AFP (alfafetoprotein) - a protein that is produced in the liver of the fetus. Detection of a high level of AFP may indicate pathologies in the development of vital basic organs. An increased level of this protein indicates anomalies in the development of the spinal cord or brain of the fetus, and he can also "talk" about Rh-conflict or the threat of miscarriage. But, it is worth noting that the increased content of AFP is considered the norm in multiple pregnancies.
Make sure the normal functioning of the placenta and that the baby gets everything you need, and the body as a whole has a sufficient level of protective forces, will help the level of free estriol.
Biochemical screening data obtained during this period are processed by a computer in order to detect genetic abnormalities.
Low level of estriol and AFP, and with it? elevated hCG may indicate Down's syndrome in the fetus.
Is biochemical screening mandatory for all expectant mothers?
Biochemical screening is an analysis not mandatory for all expectant mothers, but in many cases doctors recommend it. Here are the main indications for compulsory biochemical screening:
- if this is the first pregnancy and you are over 30 years old;
- If you have already had miscarriages before this pregnancy;
- if you have a serious infectious disease during pregnancy;
- hereditary pathologies;
- if you already have babies with chromosomal abnormalities.
Biochemical screening is your choice
With the help of biochemical screening, you have an opportunity at early pregnancy to detect violations in the development of the fetus and try to somehow influence the situation. It is always better to know in advance about the complexities and have the right to choose whether to give birth to a sick child or not. To receive a referral for this procedure, it is necessary to undergo an ultrasound examination in the first trimester of pregnancy.
Lovely future mothers, remember the main thing: in time to take all the tests, pass the necessary examinations, lead a healthy image, never and in no case despair and do not give "into the hands" of depression - and your coveted kid is sure to born cheerful and healthy!