Prenatal screening during pregnancy in the first, second and third trimesters
During pregnancy, experts monitor the development of the child’s fetus. In this, the prenatal screening is helped – a complex of research, allowing to detect pathology
During pregnancy, you can learn about the right development of the child using prenatal biochemical screening. Modern method of research makes it possible to detect pathology on the early term of its development and take measures aimed at solving the problem.
Predatal screening is carried out at different times of pregnancy, it is an absolutely safe, painless and highly efficient method.
Features of the study
Prenatal (prenatal) biochemical screening is recommended for women in order to timely detect anomalies of chromosomal and gene originations. The technique includes a three-time ultrasound and biochemical blood test.
In obstetrics and gynecology under the concept «screening» Specialists imply safe mass studies, the purpose of which is to identify the risk of intrauterine abnormalities.
The technique consists of such studies:
- Ultrasound of the fetus;
- Biochemical blood tests that allow us to determine the development of pathology, because the composition of specific blood substances in this case changes significantly.
It should be known that the first prenatal screening and all subsequent does not allow specialists to make a diagnosis, it only allows you to identify pregnant women with increased risk of developing pathologies. To determine the exact diagnosis, you will need additional research of the status of the fetus – ultrasound and invasive diagnostics.
When the study is carried out
Evaluation of the development of the fetus is carried out exclusively to all pregnant women in 1, 2 and 3 trimesters. For the first time, the woman passes a survey from 10 to 14 week of pregnancy, the optimal deadlines – 11-13 weeks.
Specialists carry out an ultrasound, whose goal is to raise the development of the fetus according to pregnancy, as well as make measurements of the collar space. This term in obstetrics and gynecology indicates the area of the cluster of the fluid in the zone of the fetus neck between the skin and soft tissues.
Normal indication of the thickness of the collar space is less than 3 mm. In the case when the indicators exceed the norm, the risk of developing some fruit anomalies arises.
«Double test»
If there are suspicions of deviations in the development of the embryo, the doctor cannot install unreasonable diagnoses, additional research will need to confirm suspicion.
To this end, a biochemical blood test is carried out in 1 trimester of pregnancy for a period of 10-13 weeks. This diagnostic method is known called «Double test», It is carried out only after an ultrasound, and it is directed to the determination of pregnant women in the blood of the level of two proteins – Rarr-P and Hgch.
This method of prenatal research has another name – Prenatal screening of trisomy.
With it, specialists can detect the risk of such anomalies of the fetus in the first trimester:
- Down syndrome – trisomy 21 chromosomes;
- Edwards syndrome;
- Defect of the nervous tube.
As a rule, such a diagnosis is carried out at the end of 1 trimester to all pregnant women, and special testimony to this are:
- age after 35 years;
- spontaneous miscarriages in history;
- hereditary diseases in close relatives;
- alcoholism, drug addiction;
- nearby marriage.
In principle, these testimony remains as not only for prenatal screening I trimester, but also two subsequent – second and third.
Conducting a prenatal screening in 1 trimester allows you to detect such common anomalies as Patau syndrome, Turner, Cornel de Large. For the methodology requires the existence of ultrasound results, made no earlier than a week before analysis.
With the results obtained, a woman should visit the Cabinet of Genetics. Specialist with the help of a special program, given the analysis data, evaluates the risks of a woman at a pregnancy.
When calculating individual risks, genetics takes into account the age of a woman, its weight, ethnicity, the presence of chronic diseases and hereditary diseases in the next relatives.
After the Consultation of the doctor, a pregnant woman can be sent for additionalness – the biopsy of the village of Chorion. This is an invasive method, the procedure relates to complex manipulations when a specialist introduces a tool for the collection of chorion through the abdominal wall or cervical channel. This term denotes the structure from which the placenta consists.
Biopsy is a very dangerous procedure, when it is incorrect, bleeding can be opened with subsequent miscarriage.
Second trimester
Predatal screening in 2 trimester is recommended in 16-18 weeks, but can be held until 20 weeks. During this period, in a pregnant woman, blood is taken on AFP, HCG, free estrilla, the study is also known under such a name as «Triple Biochemical Screening».
The doctor assesses the risks of the development of anomalies, which may be on this launch date of the fetus, given the results of the ultrasound and the conclusion of genetics made in 1 trimester.
If there are doubts about a specialist, it may appoint a woman to carry out additional invasive research methods, such as:
amniocentesis;- cordocentsis.
These methods of 2 prenatal screening also require interference in the mother’s body and can lead, like the chorion biopsy, to the fetal death. Ultrasound in 2 trimester spend on 20-24 weeks.
Ultrasonic research of the fetus in 3 trimester – by 32-34 weeks. In such a time, the late anomalies can also develop, which can be seen using ultrasound.
Each trimester of pregnancy is characterized by its features of the development of the fetus, while not to exclude the risks of anomalies, to confirm that prenatal screening and qualified specialists will help.
