Screening - what is it

Examinations to identify possible diseases have already become the norm in medical practice. In the language of doctors, such procedures are called "screening." What it is is not known to every man in the street. How is the survey carried out and what are its types, intended for different categories of the population?

How is the screening?

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While many, having heard the term for the first time, only wonder, "Screening - what is it?", The procedure with this name has been practiced for more than a century. The word "screening" itself means "screening", i.e. As a result of the analysis, a group of healthy people is eliminated. The remaining identified certain deviations. Increasingly newer and more sophisticated methods are connected to the complex survey:

• Ultrasound;
• MRI;
• CT scan;
• chromosome analysis;
• mammography;
• magnetic nuclear resonance scanning and others.

They allow you to detect the disease, when a person still feels healthy, and the external signs of pathology are completely absent. However, early screening may not always be beneficial: sometimes people do not want to know about the onset of serious diseases. Thus, the examination loses its value when the patient does not want to undergo treatment.

Mass screening becomes pointless in other cases:

• if the pathology among the population is not too common;
• if the disease is not dangerous;
• if the survey is too expensive;
• if the treatment is equally effective both before the symptoms are detected and after;
• if there are a lot of false positive or false negative results.

Unfortunately, sometimes modern methods of medical research are associated with some complications and discomfort in patients:

• if the result was false positive, people have to spend time and money on additional tests. Patients begin to worry about their health, and as a result, the diagnosis is not confirmed.
• with a false negative result, the person is not informed in time about the presence of the disease, so the diagnosis cannot be made at the moment when serious complications can be prevented.

Today, physicians are increasingly inclined to conduct mass screening only in the event of a real danger to the health of many people.

Genetic screening

The most relevant procedure is the examination of pregnant women on the possibility of abnormalities in the development of the fetus. Today, most of all screenings are carried out to identify a number of diseases in a child still in the womb:

• Down syndrome;
• Edwards syndrome;
• neural tube defects.

If the expectant mother is at risk, this does not mean that one of these diseases will develop in her baby after birth. At the same time, a negative result is also not considered 100% reliable. Candidates for being at risk are:

• women over 35;
• patients who have previously given birth to children with developmental disabilities;
• future mothers who have a big difference in age with the father of the child;
• parents with a genetic predisposition;
• women with multiple pregnancies or fertilized by IVF;
• pregnant women who took drugs prohibited during this period.

The most frequently detected problem is Down Syndrome. This disease develops in one in 600-700 women. The risk zone consists of future mothers aged 17-18 and over 35 years. For women over 40, this figure becomes threatening - 1:20. Edwards and Patau syndromes are less common, but early diagnosis is necessary.

During pregnancy, three genetic screenings are performed.

• First: between the 11th and 13th weeks. Blood is taken from a vein to conduct it. In parallel, an ultrasound is being done, which may be necessary to carry out calculations in the laboratory. The blood is analyzed for the presence of protein and hormone b-hCG and PAPP-A, so the test is also called dual. If the protein level is below the norm, it is possible that the baby will be born with Down syndrome, Edwards, Lange, or the fetal growth may stop. The test result is correct in relation to 80-90 cases out of 100. If the pathology is confirmed, the expectant mother is sent to a genetic doctor. He may recommend a placental biopsy and amniocentesis.
• Second: between the 20th and 24th weeks. During this period, blood taken from a vein is analyzed for the amount of 3 hormones: b-hCG, estriol and ACE. Elevated or reduced levels of hormones speaks either about the physical ailments of the future little one, or about genetic disorders.
• Third: between the 30th and 34th weeks. This test determines the presence of the same hormones as in the second trimester of pregnancy. In case of deviations, the doctor may advise you to dopplerometry and cardiotocography in order to investigate the process of blood flow to the fetus, uterus and placenta.

Genetic screening during pregnancy is an important procedure that allows determining fetal malformations with a 90% probability. But, unfortunately, the results of the study are not always reliable. With false positives, pregnant women begin to worry a lot. Sometimes they have to go through such a painful and dangerous procedure as a placenta biopsy. In 10% of cases, this analysis ends with a premature discharge of amniotic fluid. Without good reason, women with a false result are forced to agree to it.

How do they screen for pregnancy?

In addition to genetic screening, a woman undergoes three ultrasounds during pregnancy. As a rule, they are carried out at the same time as the collection of blood from a vein. Each time at the ultrasound examination, the doctor examines various indicators.

• The first ultrasound. It is important for the doctor to determine whether there is an ectopic pregnancy, how much fruit is in the uterus. Next, the parameters of the embryo are considered: growth from crown to coccyx, rudiments of bones, skeleton, body structure, arrangement of organs, measurements of the neck area, thickness of neck folds and more are taken. The structure and tone of the uterus, the condition in which the ovaries are located, is also evaluated.
• The second ultrasound. It is held on the 19-24 week. The objective of this study is to evaluate the development of the fetus, the sex of the child, to identify chromosomal abnormalities, as well as malformations of the internal organs of the embryo, to determine the state of the amniotic fluid and the placenta.
• The third ultrasound. Done at 32-34 week. At this time, it is not so much the developmental parameters of the fetus that are important as the state of the placenta, the prognosis of a possible cord entanglement around the baby’s neck. These indicators are necessary for planning childbirth - whether the woman will give birth herself or a cesarean section will be required.

In conjunction with biochemical analysis of blood, ultrasound provides reliable results on fetal pathology. In especially dangerous cases at an early stage of pregnancy, the question of its termination may be raised.

Audiological screening of newborns

After the birth, the baby will also undergo a series of screenings - tests for congenital diseases. Audiological research involves testing the hearing of babies. Today, this procedure is required for all children.

Screening is carried out in the hospital for 3-4 days or in the hospital. If for some reason the child has failed to pass this test, he is sent for analysis to the clinic. To study the pathologies of hearing, the child is introduced into the ear canal an electro-acoustic probe with a miniature telephone and microphones. The probe is connected to the device, which registers the UAE. Screening should be carried out in complete silence. Best of all, if the baby at this moment will sleep.

The device responds in two forms: “Pass” or “Fail” notifications appear on the screen. In the second case, if doctors do not see a clear problem, additional research will have to be done.

Screenings in modern medicine are the necessary procedures for identifying possible pathologies in a certain group of the population. However, doctors, diagnosing only on the basis of the results of these studies and sending the patient to more expensive and painful tests to confirm, should be aware of the great responsibility for such a decision. From what shows the screening may depend on the fate and health of a person.