Biochemical screening is an analysis that is prescribed to pregnant women to identify various pathologies in the fetus. Such an examination helps to identify serious diseases, defects, mutations in the early stages.
What is biochemical screening
As the fetus develops, the placenta begins to secrete special substances into the blood of the expectant mother. Biochemical analysis is just aimed at the study of these substances. A deviation from the norm may indicate that the pregnancy is not proceeding smoothly. Screening is prescribed twice for the entire period of pregnancy. The first examination takes place in the first trimester at 10-14 weeks, and the second at 16-20 weeks.
Do I need to conduct a biochemical analysis
Experts recommend doing this analysis without fail. Because no woman is immune from the development of pathologies in her baby. This is due to a hereditary factor, lifestyle, ecological situation. The World Health Organization, in turn, recommends that screening be carried out at least in the second trimester. Each expectant mother has the right to independently decide to conduct an analysis or not, but it does not hurt to insure herself once again. This will help to avoid further problems.
Risk group
For women at risk, doctors prescribe screening twice. This group includes: women over 35; women with genetic abnormalities in the family; expectant mothers who have had infectious diseases in early pregnancy; if the mother and father are close relatives; if a woman has previously had a miscarriage, stillbirth, birth of a child with pathologies.
Screening in the first and second trimester
Biochemical screening in the first trimester reveals two substances: hCG, PAPP-A. Doctors determine the amount of each of the substances in the body of the expectant mother and check if there are any deviations from the norm. If the specialist suspects abnormalities in the development of the embryo, then an ultrasound scan is prescribed. A single analysis gives a reliable prognosis in 60% of cases, but in conjunction with an ultrasound examination, the percentage rises to 80. Screening in the first trimester reveals Down syndrome and Edwards syndrome.
In the second trimester, three substances are detected during the analysis: hCG, AFP, NE. At a later date, the following abnormalities in the development of the fetus can be detected: malformation of the neural tube, anomaly of the kidneys, and infection of the abdominal wall.
The following factors can affect the result of biochemical screening: multiple pregnancy, IVF, bad habits of the mother (especially smoking), the presence of serious diseases (colds, diabetes). The indicators will even depend on the weight of the woman. In thin women, they are underestimated, in full ones, on the contrary.
