Prenatal Screening

Prenatal screening is one of the most important methods of examining pregnant women, allowing to detect possible gross abnormalities of the fetus, or indirect signs of such anomalies. It is considered one of the most simple, safe and informative diagnostic methods for expectant mothers. Screening refers to those surveys that are conducted massively, that is, for all pregnant women without exception.

The survey consists of two elements:

1. Prenatal biochemical screening - analysis of the venous blood of the mother to determine certain specific substances that indicate a particular pathology.
2. Ultrasonic examination of the fetus.

Prenatal screening of trisomy is one of the most important studies that is not mandatory, but it is recommended that if the future mother is more than 35 years old, if children with genetic abnormalities have already been born in the family, and if there is a hereditary burden. This analysis helps to identify the risk, that is, in fact, the probability of the birth of a baby with Edwards disease (trisomy 18 chromosomes - multiple malformations of internal and external organs, mental retardation), Down's disease (trisomy 21 chromosomes) or neural tube defect (eg, splitting spine), Patau syndrome (trisomy 13 chromosomes - severe defects of internal and external organs, idiocy).

Prenatal screening for 1 trimester

In the first trimester, the examination is carried out at the gestational age of 10-14 weeks and allows to determine whether the development of the fetus corresponds to the time, whether there is multiple pregnancy, whether the baby is developing normally. At this time, trisomy 13, 18 and 21 are also screened. The ultrasound physician must measure the so-called collar space (the area where fluid accumulates in the neck area between the soft tissues and the skin) to ensure that there are no abnormalities in the development of the child. The results of ultrasound are compared with the results of a woman's blood test (the level of the pregnancy hormone and RAPP-A protein is measured ). Such a comparison is made using a computer program that takes into account the individual characteristics of the pregnant woman.

Prenatal screening for the 2nd trimester

In the second trimester (at 16-20 weeks), a blood test is also performed on AFP, hCG and free estriol, and ultrasound of the fetus is performed and the risk of trisomy 18 and 21 is assessed. If there is reason to believe that something is wrong with the baby, then a direction is given to invasive diagnostics related to piercing of the uterus and the collection of amniotic fluid and fetal blood, but in 1-2% of cases such procedures are the cause of pregnancy complications and even the death of the child.

In the third trimester, at 32-34 weeks, ultrasound is performed for the purpose of detecting late diagnosed abnormalities.