Remembering the time of their pregnancy, many women speak not so much about pleasant experiences as about constant visits to the clinic for examinations. Indeed, during the gestation period, great attention is paid to the state of health of the woman. The expectant mother constantly undergoes examinations, passes tests, some of which help to objectively assess the state of her body, while others assess the development of the child. Among the analyzes, there are special studies aimed at identifying genetic pathologies of fetal formation, the so-called screenings, there are two of them: the first and second screening during pregnancy.
What is this examination aimed at?
Screening is aimed at identifying women whose test results differ significantly from the norm, and they constitute a risk group. Focusing on the research results, doctors predict the possibility of having children with Down syndrome, Edwards, abnormal neural tube formation. Compulsory examination is carried out for women whose first pregnancy occurred after 35 years, having children with gene abnormalities, etc. The examination consists of two stages: biochemical screening and ultrasound screening of pregnant women. A blood test helps determine the presence of special markers, and an ultrasound examination will help identify obvious signs of abnormal development.
First trimester screening
At the time of gestation of the fetus equal to 11 - 13 weeks, the doctor recommends screening for the first trimester. It is necessary to start with an ultrasound examination, which will help to correct the estimated gestational age, to determine the presence of multiple pregnancy, pathology of pregnancy. For the doctor, an indicator of the thickness of the collar space (TBP) is informative, a value of which more than 3 mm can indicate the likelihood of developing a pathology (for example, Down's syndrome). The doctor will also evaluate the coccygeal-parietal size of the fetus (CTE), this indicator should be ≥ 45.9 mm.
Blood biochemistry establishes levels of the hCG hormone and PAPP-A protein. The norm of the hCG hormone at 11 to 12 weeks is 20 thousand-90 thousand units / ml, for a period of 13-14 weeks it is 15 thousand-60 thousand units / ml. An increase in values indicates a multiple pregnancy, existing pathologies of the formation of the fetus. The lowering of the values is about the pathology of the development of pregnancy (developmental delay, frozen pregnancy, fetal death).
The norm of PAPP-A protein at this period is 0.1 - 6.01 mU / ml. An increase in the level is an indicator of developmental disorders at the level of chromosomes. After receiving the results of the research, the doctor will conclude about the nature of the course of pregnancy and classify the woman as a certain risk group. But even if you are prescribed a second screening during pregnancy, you have no reason to worry.
Second Trimester Screening
The most favorable time for the examination is from 16 to 18 weeks of pregnancy. The studies that make up the second screening during pregnancy are the same as the first. During the examination, the doctor will reveal the hormonal level of the placenta and the level of fetal liver hormones.
The second screening during pregnancy begins with an ultrasound scan, which is mandatory before the biochemical analysis. The interval between ultrasound and blood donation for analysis should not exceed three days.
The normal level of hCG hormone in this period should be 10 thousand - 35 thousand mU / ml. The level of AFP hormone is normally 15-19 U / ml. An increase with a high degree of probability indicates anomalies in the development of the neural tube, the development of craniocerebral hernia, the abnormal formation of the digestive system and liver. A decrease in the AFP level indicates the presence of chromosomal abnormalities or intrauterine death.
During this period, the doctor will determine the level of free extriol, which is constantly increasing with the duration of pregnancy. For a period of 15-16 weeks, it is equal to 5.4-21.0 nmol / L, from 17 to 18 weeks it increases to 6.6 - 25.0 nmol / L. A significant excess of these values indicates a large weight of the child and a disease of the liver or kidneys of a pregnant woman. A low level indicates the existing oxygen starvation of the fetus, the presence of infection, chromosomal pathologies.
The decision is made by the woman
Even if you are included in the risk group and do not want to conduct screening tests, the doctor is not entitled to force you. However, the expectant mother should remember that from the very first weeks of pregnancy she is responsible for the life and health of her, even if not yet born, child.