As a rule, every woman, visiting the office of perinatal diagnostics, is warned in advance about what kind of research she has to go through. However, not everyone knows what these terms mean. Let us consider them in more detail.
So, with invasive methods the doctor with the help of special tools penetrates into the uterus cavity for the sampling of the biomaterial and sends it for further research. Non-invasive, therefore, on the contrary, - diagnosis does not involve "invasion" of the reproductive organs. It is these methods that are most often used when establishing pathologies of pregnancy. This is partly due to the fact that invasive methods presuppose a higher qualification of a specialist. at their carrying out the big risk of damage of reproductive organs or a fetus.
What concerns non-invasive methods of perinatal diagnosis?
Under this type of study, as a rule, understand the conduct of so-called screening tests. They include 2 stages: ultrasound diagnostics and biochemical analysis of blood components.
If we talk about ultrasound as a screening test, then the ideal time for him is 11-13 weeks of pregnancy. At the same time, the attention of physicians is attracted to such parameters as KTP (coccygeal-parietal size) and TVP (thickness of the collar space). It is by analyzing the values of these two characteristics that specialists with a high degree of probability can assume the presence of chromosomal pathologies in a baby.
If suspicion of such are present, a woman is assigned a biochemical blood test. In this study, the concentration of substances such as PAPP-A (pregnancy-associated plasma protein A) and the free subunit of chorionic gonadotropin (hCG) are measured.
What is the reason for invasive diagnosis?
As a rule, this kind of research is conducted to confirm existing data from previous surveys. Basically, these are those situations when the baby has an increased risk of developing chromosomal abnormalities, for example, this is usually noted when:
- late pregnancy (the age of the future mother is more than 35 years);
- presence in the family of a child with similar disorders;
- when in the family the carrier of a chromosomal pathology is revealed;
- transferred during the gestation of the fetus hepatitis, rubella, toxoplasmosis;
- presence in the anamnesis of 2 and more spontaneous abortions.
The most commonly used of invasive diagnostic methods are chorionic villus biopsy and amniocentesis. In the first case, for diagnosis from the uterus, with the help of a special instrument, a piece of chorionic tissue is taken, and the second -
Such manipulations are always carried out exclusively under the control of the ultrasound machine. As a rule, for the appointment of invasive methods of perinatal diagnosis, it is necessary to have positive results from previous screening tests.
Thus, as can be seen from the article, the methods of perinatal diagnostics considered are complementary. However, the most frequently used are non-invasive; they have a lower risk of trauma and allow a high probability to assume a chromosomal disorder in a future baby.