First and second screening for pregnancy: are they so necessary
Remembering the time of your pregnancy, manywomen say not so much about pleasant experiences as about constant trips to a polyclinic for examinations. Indeed, during the period of bearing great attention is paid to the woman's health condition. The future mother constantly undergoes examinations, gives tests, some of which help objectively assess the condition of her body, others assess the development of the child. Among the analyzes, there are special studies aimed at revealing the genetic pathologies of fetal formation, the so-called screenings, their two: the first and second screening in pregnancy.
What is this examination directed at?
The screening is aimed at identifying women,the results of analyzes of which differ significantly from the norm, they constitute a risk group. Based on the results of the research, physicians predict the possibility of giving birth to children with Down's syndrome, Edwards, an abnormal formation of the neural tube. Mandatory examination is performed on women whose first pregnancy occurred after 35 years, having children with genetic abnormalities, etc. The survey consists of two stages: biochemical screening and screening of pregnant uzi. The blood test helps to determine the presence of special markers, and ultrasound examination will help to reveal obvious signs of abnormal development.
First trimester screening
At the gestation period of the fetus is 11 - 13 weeksthe doctor recommends that the first trimester be screened. It is necessary to start with an ultrasound examination, which will help to correct the expected duration of pregnancy, to determine the presence of multiple pregnancy, the pathology of pregnancy. For a doctor, the indicator of the thickness of the collar space (TVP), the value of which is more than 3 mm, can speak about the probability of pathology development (for example, about Down's syndrome). The doctor will also assess the coccygeal-parietal fetal size (CTE), this figure should be ≥ 45.9 mm.
Biochemistry of blood sets the level of the hormone hCGand PAPP-A protein. The norm of the hormone hCG in 11 - 12 weeks is 20 thousand-90 thousand mU / ml, at a period of 13 - 14 weeks is equal to 15 thousand to 60 thousand mU / ml. The increase in values indicates a multiple pregnancy, the existing pathologies of fetal formation. Decrease in values - about the pathology of development of pregnancy (delay in development, frozen pregnancy, death of the fetus).
The protein norm of PAPP-A at this time is 0.1 -6.01 IU / ml. Increase in the level is an indicator of developmental disorders at the chromosome level. Having received the results of the research, the doctor will make a conclusion about the nature of the pregnancy and will refer the woman to a certain risk group. But even if you were given a second screening during pregnancy, you have no reason to worry.
Second trimester screening
The most favorable time forexamination from 16 to 18 weeks of pregnancy. Studies that make up the second screening for pregnancy are the same as the first. Upon examination, the doctor will reveal the hormonal level of the placenta and the level of the fetal hepatic hormones.
The second screening for pregnancy begins withultrasound, which is mandatory before the delivery of biochemical analysis. The interval between the conduct of ultrasound and the delivery of blood for analysis should not exceed three days.
The normal level of hCG hormone during this periodshould be 10 thousand to 35 thousand mU / ml. The level of the hormone AFP is normally 15-19 U / ml. The increase with a high probability indicates anomalies of neural tube development, development of craniocerebral hernia, abnormal formation of the digestive system and liver. A decrease in the level of AFP indicates the presence of chromosomal abnormalities or intrauterine death.
During this period the doctor will determine the level of freeExtriol, which is constantly increasing with the period of pregnancy. At a period of 15 to 16 weeks, it is 5.4-21.0 nmol / l, increases from 6.6 to 25.0 nmol / l from 17 to 18 weeks. A significant excess of these values indicates a large child's weight and liver or kidney disease of a pregnant woman. A low level indicates the presence of oxygen starvation of the fetus, the presence of infection, chromosomal pathologies.
The decision is taken
Even if you are included in the risk group and do not wantto conduct screening studies, the doctor has no right to force you. However, the future 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.