It will be necessary to donate blood from the vein and come to a consultation on deciphering the biochemical screening conducted in the 2nd trimester, precisely to the clinic where the analysis was performed, because the results vary in different laboratories.
Not everyone knows that biochemical screening in the 2nd trimester is voluntary and the doctor can not force the pregnant woman to go through it if she does not consider it necessary. In addition, the triple test for hormones is paid.
What does second trimester screening mean?
In order to detect abnormalities of fetal development, a triple test is carried out, that is, blood is taken for such hormones:
- Alfafetorothein.
- Human chorionic gonadotropin.
- Free estriol.
Since the test has three components, it was called triple, although some laboratories check only two indicators - AFP and hCG.
Norms of biochemical screening of the 2nd trimester
As already mentioned, different laboratories have different tables of standards, and therefore it makes sense to talk only about deviations from these figures. Thus, an increase in 2 MoH hCG indicates a multiplicity or Down syndrome, a decrease of 0.5 MoM indicates a risk of multiple malformations (Edwards syndrome).
The AFP rate for the period of 18-20 weeks is 15-100 units, or 0.5-2 Mom. If there is a deviation from the norm in the smaller direction, then there is a risk of developing Down syndrome and Edwards syndromes.
Norm of free estriol - from 0.5 to 2 MoM, the deviation from which implies:
- a lower rate - the syndromes of Edwards and Down;
- elevated - multi-fruit, large fetus, liver and kidney disease.
The level of estriol is influenced by the intake of medicines, especially hormones and antibiotics. It is necessary to warn about it before carrying out of analyzes.