What gives screening 1 trimester. Screening of the first trimester of pregnancy - what you need to know about the norms and results
The direction for screening surveys causes a panic mood in future mothers. There is a lot of questions - what is it, is it not dangerous for the baby, why send me? To unnecessarily not worry about such a responsible period, it is better to deal with this question in advance.
What is Screening
Women in the child, the Ministry of Health recommends passing the first trimester of the examination in order to determine the anomalies in the early deadlines with the growth of the fetus. Perinatal check does not seem to be threatening for the mother with the child. The price of the study is available, therefore it is not worth risking the life of the future kid. Screening during pregnancy contributes to identifying:
- genetic pathologies;
- indirect signs of violations;
- fetal defects.
Be sure to make screening during pregnancy in 1 trimester, all who enters the risk area. These are women who have:
- father of a child who received irradiation;
- age category over 35 years old;
- threat of abortion;
- hereditary diseases;
- professional harm;
- children born with pathologies;
- previous frasonal pregnancy, miscarriage;
- related relationship with the father of the child;
- narcotic, alcohol addiction.
First screening during pregnancy
It is important for the first time to spend screening check if the price of the question is the life of the future kid. What can be detected during the survey? Screening of the first trimester can detect:
- defects of the central nervous system;
- genetic diseases - Edwards syndromes, Down;
- the presence of umbilical hernia;
- slow rising skeleton bones;
- brain impairment;
- freight or deceleration of heartbeat;
- one cord artery (must be two).
What looks at the first screening
An important component of the calm state of mom and confidence in the correct development of the baby are screenings during pregnancy. Important fetal parameters are measured in the implementation of the first ultrasound examination:
- the magnitude between the dumplings;
- TVP - Gabritary thickness of the collar space;
- cTR size - from the tailbone to the dice on the temperature;
- bone length - forearm, hips, shin, shoulder;
- heart size;
- head circumference;
- vessel dimensions;
- the distance between the frontal, the occipital bones;
- cardiac frequency.
First screening during pregnancy - the timing
What determines the time of the first screening research? An important indicator in the fetus is considered the thickness of the collar space. The period when the first screening is made - the beginning of 11 weeks, previously the value of the TVP is too small. The end of the term is associated with the formation of the fetal lymphosystem. After 14 weeks, the space is filled with liquid, it may increase, as in pathology - and the results will not be objective. The end of the term is considered to count 13 weeks plus an additional 6 days.
Preparing for screening 1 trimester
Ultrasound examination does not imply preparation if the inspection is carried out through the vagina. When checking through the abdominal wall, you need to fill the bladder with three glasses of water for 1.5 hours before start. How to prepare for screening 1 trimester, its second component - blood test? To obtain an objective result required:
- two days before there are no seafood, nuts, chocolate, smoked and fried food;
- in the morning on the day not to drink anything;
- to donate on an emptycle.
How do the first screening during pregnancy
Wanting to exclude defects, determine the non-compliance with the development of the fetus, women in the first trimester send to the examination. After deciphering the results, comparing them with the standards, make a decision. With bad indicators, abortion is possible. How is the screening of 1 trimester? The study includes two stages:
- ultrasonic inspection at which the fetus measurements are made, the characteristics of its livelihoods are established, the state of the uterus;
- biochemical analysis of maternal blood detecting the absence of chromosomal defects.
First screening during pregnancy - norms
After the study, the resulting indicators specialists compare with standards. An important point is the dependence of these values \u200b\u200bfrom the correct period of pregnancy: what exactly the week a check was carried out. 1 trimester screening standards for ultrasound results are:
- copchiko-dark size - 34-75 mm;
- is present, not measured under a period of 11, 12 weeks, the nasal bone, further, the value exceeds 3 millimeters;
- heart abbreviation frequency - 147-178 shots per minute;
- the size between the dark bones is 13-28 mm;
- the thickness of the collar space is in zone 0.8 - 2.7 mm.
Your standards are available in biochemical hemoanalysis. They have an influence of a week study. After receiving the results, a MOM coefficient is calculated using a computer showing deviations of the fetus. The parameters are proportion to the term:
- beta-hCG - 14.2-130.9 ng / ml;
- the estimated coefficient of IOM - 0.51-2.5;
- Rarr-A - 046- 8.53 honey / ml.
Uzi screening 1 trimester
The main survey of this period is ultrasound. According to its results (in concerns of chromosomal defects), blood tests are prescribed. Screening ultrasound 1 trimester checks from the fetus, except for measuring the parameters:
- structure and symmetry of the brain;
- blood flow of venous duct;
- presence of cord hernia;
- position of the stomach, heart;
- the number of vessels of umbilical cord.
When screening research, measurements and monitoring of the state of pregnant women are carried out. Indicators will talk about threats for the development of the fetus. The oversized tone of the uterus can provoke a spontaneous abortion. During the inspection of ultrasound, a woman is determined by:
- location, the thickness of the placenta;
- tone of the uterus;
- the number of accumulating waters;
- picture of zea cervix.
Biochemical Screening
With the departments revealed under ultrasound, to clarify the threat of chromosomal pathologies, blood tests are prescribed. The results are interconnected with deadlines precisely defined in ultrasound examination. For analysis, the serum of maternal venous blood is taken. According to the results, the risk of anomalies is calculated. Gemotest determines 2 parameters that are compared with the standard:
- free beta subunit hCG;
- plasma protein A - RARR-A.
Screening 1 trimester - decoding results
Specialists using computer processing after research makes deciphering research. Script results 1 trimester depend on the week on which they are conducted, have different indicators. When performing an ultrasound:
- determine the presence and value of the nasal bone - more than 3 millimeters;
- the thickness of the collar space is measured - the increased indicator indicates the likelihood of pathology.
Deciphering the results of blood biochemistry is also associated with a week on which:
- beta-hCG indicators below the standard - the likelihood of ectopic, frozen pregnancy, miscarriage;
- results High - Possible toxicosis, the presence of several fruits, tumors, Down syndrome;
- rarr-A values \u200b\u200bare greater than the threat of interrupts, frozen pregnancy;
- data is lowered - the Downward Syndrome, Edwards, miscarriage.
Price to screen 1 trimester
Screening research is carried out in perinatal clinics, medical centers. Some of them have sites where catalogs can be ordered and buy in the online store (often at a discount) required surveys. These include a double test during pregnancy, ultrasound. How much is the screening of 1 trimester? The stated price is due to the level of institution, equipment, personnel experience. Distribution of value in rubles is:
- Ultrasound - 1600-5000;
- double hemotest - 1400-3100.
Video: Screening 12 weeks
Screening surveys help to identify the risk of chromosomal diseases in a child before his birth. In the first trimester of pregnancy, an ultrasound and biochemical blood test on hCG and RARR-A are carried out. Changes in these indicators may indicate the increased risk of Down syndrome at the future child. Let's see what the results of these analyzes mean.
At what time?
Screening 1 trimester is made on a period of 11 weeks to 13 weeks and 6 days (the term is calculated from the first day of the last menstruation).
Signs of Down syndrome on ultrasound
Norms for the free β-subunit hCG in the first trimester:
- 9 weeks: 23.6 - 193.1 ng / ml, or 0.5 - 2 moments
- 10 weeks: 25.8 - 181.6 ng / ml, or 0.5 - 2 mom
- 11 weeks: 17.4 - 130.4 ng / ml, or 0.5 - 2 moments
- 12 weeks: 13.4 - 128.5 ng / ml, or 0.5 - 2 mom
- 13 weeks: 14.2 - 114.7 ng / ml, or 0.5 - 2 mom
Attention! Norms in NG / ml may differ in different laboratories, so the specified data is not final, and in any case you need to consult with your doctor. If the result is specified in IOM, then the norms are the same for all laboratories and for all analyzes: from 0.5 to 2 MΩ.
What if HCG is not normal?
If the free β-subunit of the hCG is higher than the norm for your period of pregnancy, or exceeds 2 MΩ, then the child has increased risk.
If the free β-subunit of the HCG is below the norm for your term of pregnancy, or is less than 0.5 MΩ, then the child has increased risk.
RARR-A
Rarr-A, or as it is called, "plasma protein A, associated with pregnancy", this is the second indicator used in the biochemical screening of the first trimester. The level of this protein is constantly growing during pregnancy, and the rejection of the indicator may indicate various diseases of the future child.
The rate for RARR-A, depending on the term of pregnancy:
- 8-9 weeks: 0.17 - 1.54 honey / ml, or from 0.5 to 2 mΩ
- 9-10 weeks: 0.32 - 2, 42 honey / ml, or from 0.5 to 2 mΩ
- 10-11 weeks: 0.46 - 3.73 honey / ml, or from 0.5 to 2 mΩ
- 11-12 weeks: 0.79 - 4.76 honey / ml, or from 0.5 to 2 mΩ
- 12-13 weeks: 1.03 - 6.01 honey / ml, or from 0.5 to 2 mΩ
- 13-14 weeks: 1.47 - 8.54 honey / ml, or from 0.5 to 2 mΩ
Attention! Norms in honey / ml may differ in different laboratories, so the specified data is not final, and in any case you need to consult with your doctor. If the result is specified in IOM, then the norms are the same for all laboratories and for all analyzes: from 0.5 to 2 mΩ.
What if Rarr-and is not normal?
If Rarr-and is below the norm for your term of pregnancy, or is less than 0.5 MΩ, then the child has increased risk and.
If Rarr-A is higher than the norm for your term of pregnancy, or exceeds 2 MΩ, but the remaining screening indicators are normal, then there is no reason for concern. Studies have shown that in a group of women with an elevated level of RARR-A during pregnancy, the risk of diseases of the fetus or pregnancy complications are not higher than that of other women with a normal RARR-A.
What is risk and how is it calculated?
As you could have seen each of the indicators of biochemical screening (HCG and RARR-A) can be measured in IOM. IOM is a special value that shows how much the result of the analysis differs from the average result for this period of pregnancy.
But still, at HCG and RARR-A, not only the term of pregnancy, but also your age, weight, do you smoke, what diseases you have, and some other factors. That is why, for more accurate screening results, all its data is recorded in a computer program that calculates the risk of disease in a child individually for you, given all your features.
Important: For the correct counting of risk, it is necessary that all analyzes have surrendered in the same laboratory in which the risk is calculated. The risk counting program is configured to special parameters, individual for each laboratory.Therefore, if you want to double-check the screening results in another laboratory, you will need to pass all the analyzes re-.
The program gives the result in the form of a fraction, for example: 1:10, 1: 250, 1: 1000 and the like. Understand the fraction follows this:
For example, risk 1: 300. This means that of 300 pregnancies with such indicators as you have, one child is born with Down syndrome and 299 healthy children.
Depending on the resulting fraction, the laboratory issues one of the conclusions:
- Test is positive - the high risk of a child's syndrome in a child. It means that you need a more thorough examination to clarify the diagnosis. You can be recommended or.
- Test negative - low risk of a child's syndrome in a child. You will need to go through, but no additional surveys are needed.
What if I have a high risk?
If, as a result of the screening, you had a high risk of birth of a child with Down syndrome, then this is not a reason to fall into panic, and even more so, to interrupt pregnancy. You will be sent to a consultation to the doctor genetics, which will again look at the results of all surveys and, if necessary, will recommend to pass surveys: the biopsy of the Vorsin of Chorion or Amniocentesis.
How to confirm or disprove screening results?
If you think that screening you were incorrectly, you can repeat the examination in another clinic, but for this you will need to re-pass all the tests and take the ultrasound. It will be possible only if the term of pregnancy at this moment does not exceed 13 weeks and 6 days.
The doctor says I need to make an abortion. What to do?
Unfortunately, there are such situations where the doctor persistently recommends or even makes the abortion on the basis of screening results. Remember: No doctor has the right to such actions. Screening is not the final method of diagnosing Down syndrome and, only on the basis of poor results, it is not necessary to interrupt pregnancy.
Tell me that you want to consult with genetic and pass diagnostic procedures to identify Down syndrome (or other disease): Biopsy Vorce Horion (if you have 10-13 weeks of pregnancy) or amniocentesis (if the term of pregnancy is 16-17 weeks).
Biochemical screening is a study of the blood of a pregnant woman to determine specific markers, helping to determine the likelihood of the presence of severe genetic disorders.
Since its formation, the placenta begins to produce certain substances, which then penetrate the maternal blood. The number of these markers is constantly changing as the fetus develops. Determining these substances and is the basis of biochemical screening: significant deviations of the results obtained from accepted norms and talk about the high possibility of having chromosomal anomalies or.
informationOf course, such laboratory studies cannot diagnose, but they help to take away the children with high risk of children with pathology and offer them a further in-depth examination to clarify the situation.
Biochemical screening is performed twice for the entire period of the baby tool: in the first trimester (10-14 weeks) and in the second trimester (16-20 weeks).
Indications for holding
The question of the need to perform biochemical screening in all pregnant women still remains controversial. Most experts recommend this test to all patients, because no one is insured against genetic violations. The World Health Organization (WHO) recommends at least fulfilling laboratory research in all pregnant women.
This analysis is not mandatory, and the decision to fulfill is voluntary for each future mother, although, of course, it will not hurt himself once again.
In addition, groups of women who have a high risk of birth of children with genetic pathology are highlighted. Such patients should be examined twice for all the time of gestation.
At-risk groupsrequiring compulsory biochemical screening:
- Women's age older than 30 years old at first pregnancy and over 35 years old at the second and subsequent;
- 2 and more spontaneous interruption of pregnancy in history;
- Independent reception of drugs in early periods with teratogenic effect;
- Infectious diseases transferred in the first trimester;
- The presence in the family of relatives with genetic anomalies;
- The presence of genetic anomalies in one or both parents;
- Birth earlier in a child's family with genetic anomalies;
- Stopping or the death of another child from the malformations in the family earlier;
- Marriage between close relatives;
- Radioactive exposure of one or both parents before conception or in early pregnancy;
- Deviations found in the ultrasound of the fetus.
First biochemical screening
The biochemical screening of 1 trimester is carried out in 10-14 weeks, but most experts consider more informative research in 11-13 weeks.
The first screening is a "double test", i.e. Two substances are determined in the blood: (in particular, a free unit of human chorionic gonadotropin) and RARR-A (plasma protein A associated with pregnancy).
Norma
Chorionic gonadotropin is highlighted by cells of chorion (the shell of the embryo), so it is determined in the blood, it begins early (already in the first days after the conception occurred). Further, its number gradually increases, reaches a maximum by the end of the first trimester, then begins to decline and from the second half of pregnancy remains at a constantly level.
Normal indicators hCG
RARR-A. - This is a protein produced by trophoblast throughout the period of gestation, its number increases constantly proportional to the period of pregnancy.
RARR-A Normal Indicators
| Pregnancy term, week | Normal indicators RARR-A, honey / ml | |
| Minimum value | Maximum value | |
| 8-9 | 0.17 | 1.54 |
| 9-10 | 0.32 | 2.42 |
| 10-11 | 0.46 | 3.73 |
| 11-12 | 0.7 | 4.76 |
| 12-13 | 1.03 | 6.01 |
| 13-14 | 1.47 | 8.54 |
additionallyThe result of biochemical screening is estimated not only for the results obtained, but also by the value of MΩ, which is eventually a defining factor. MΩ is a coefficient showing the degree of deviation of the resulting indicator from the average normal indicator for this period of pregnancy. IOM norm ranges from 0.5 to 2.5 (with multiple pregnancy up to 3.5 MΩ).
Decoding
Decoding biochemical screening Must be carried out only by the attending physician. It should be borne in mind that each laboratory, depending on the reagents used, can be their standards of indicators, in connection with this using incorrect data, you can get false results.
Deciphering Analysis on HCG
| Deviation of the indicator from the norm | The reasons |
| Reduced Level HCG | |
| Delay in the development of embryo | |
| High risk of spontaneous miscarriage | |
| Edwards Syndrome Fetal | |
| Increased level of hCG | Multiple pregnancy |
| Expressed toxicosis | |
| Mother diabetes | |
| Down syndrome in the fetus | |
| Pronounced malformations of the fetus (cardiovascular, nervous systems and others) | |
| Reception of gestagenic preparations () | |
| Malignant diseases (bubbling, chorioncarcinoma) |
Decoding analysis for RARR-A
Biochemical Screening in the second trimester
The biochemical screening of 2 trimester consists of a "triple test": Definition of AFP (alpha-fetoprotein), hgch and free estriol. The analysis is performed from 16 to 20 week, but the most informative will be the survey of 16-18 weeks.
Norms "Triple Test"
Afp - The protein produced in the gastrointestinal tract and the liver of the fetus from the early timeline of its development.
Normal indicators of AFP
Normal indicators hCG
Free estriol. - This is a hormone, generated initially only a placenta, and then the child's liver. With the normal course of pregnancy, the amount of free estriol is constantly increasing.
Normal indicators of free estriol during pregnancy
Decoding
2 Biochemical screening should also be decrypted only by the attending physician, taking into account the norms of this laboratory.
Deciphering Analysis on AFP
Decoding Analysis on Free Estivals
Screening 1 (first) trimester. Screening time. Screening results. Uzi screening.
Your baby overcame all the difficulties and dangers associated with the embryonic period. It was safely reached on phallopy tubes to the uterus, the trophoblast invasion was occurred in the endometrium, the formation of chorion. The embryos of Ros and incredibly changed from each week, the rigids of all the most important organs and systems were formed, the formation of the body, head, limbs.
Finally, Doros up to 10 weeks, acquiring all the necessary features like a child's configuration, which made it possible to call it from this moment the fruit.
The time of screening 1 (first) trimester has come.
Today we will talk about the timing of the screening of the first trimester, obtained the results of ultrasound screening.
The topic of this extensive and one article here is certainly not separated. We have to disassemble many anomalies and malformations of development that can already be suspected or even diagnosed on this period. But start first.
What is screening?
Screening- This is a combination of the necessary measures and medical research, tests and other procedures aimed at preliminary identification of persons, among which the probability of the presence of a certain disease is higher than that of the rest of the surveyed population. Screening is only the initial, preliminary stage of the population survey, and persons with positive screening results need a subsequent diagnostic examination to establish or eliminate the fact of the presence of a pathological process. The impossibility of the implementation of diagnostic tests to establish or eliminate the fact of the presence of a pathological process with a positive result of screening, makes it meaningless to conduct the screening itself. For example, the conduct of biochemical screening of chromosomal diseases of the fetus is not justified if the subsequent prenatal karyotyping is impossible in this region.
Conducting any screening program must be accompanied by clear planning and assessment of the quality of screening, as any screening test, conducted in the general population, can bring more harm than the benefits for the persons surveyed. The concept of "screening" has fundamental ethical differences from the concept of "diagnostics", since screening tests are carried out among potentially healthy people, so it is very important that they have realistic ideas about the information that this screening program provides. For example, when carrying out ultrasound screening of the chromosomal pathology of the fetus in the first trimester of pregnancy, women should not have the idea that the identification of the thickness of the collar space (TVP) in the fetus necessarily indicates the presence of a Dauna disease and requires interruption of pregnancy. Any screening has certain limitations, in particular, the negative result of the screening test is not a guarantee of the absence of the disease, in the same way as the positive result of the test does not indicate its availability.
When and why was the screening I trimester?
Each woman has a certain risk that her child can have chromosomal pathology. It is for each, and no matter what way of life, it leads and social status takes.
When conducting systematic (low-minded) screening, a certain screening test is offered to all persons of a particular population. An example of such screening is ultrasonic screening of chromosomal fetal anomalies in the first trimester of pregnancy, which is offered to everyone without exception to pregnant women on the period 11-13 (+6) weeks.
So, screening of the first trimester - This is a combination of medical studies conducted on a period of 11-13 (+6) weeks, and aimed at preliminary identifying pregnant women, among which the likelihood of the birth of a child with chromosomal anomalies (ha) is higher than that of the other pregnant women.
The main place among the detected ha occupies Down syndrome (trisomy of 21 pairs of chromosomes).
English doctor John Langdon Down first in 1862 described and described the syndrome, subsequently named after him as the form of a mental disorder.
Down syndrome is not a rare pathology - on average one case is observed at 700 genera. Until the middle of the 20th century, the causes of Down syndrome remained unknown, but the relationship between the probability of birth of a child with Down syndrome and the mother's age was also known that the syndrome was exposed to all races. In 1959, Zherom Lezhen found that Down Syndrome arises due to the trisomy of the 21st pair of chromosomes, i.e. The karyotype is represented by 47 chromosomes instead of normal 46s, since the chromosomes of the 21st pair, instead of the normal two, are represented by three copies.
In 1970, the first method of screening trisomy 21 in a fetus, based on increasing the likelihood of this pathology, with an increase in the age of a pregnant woman was proposed.
When screening, based on the age of mothers, only 5% of women will fall into the "High Risk" group, and this group will include only 30% of fruits with trisomy 21 from the entire population.
In the late 1980s, screening methods that take into account not only age, but also the results of studying the concentration of such biochemical products of fruit and placental origin in the blood of a pregnant woman, like alpha-fetoprotein (AFP), non-contoyted estriotropin (UE3), chorionic gonadotropin (hgch ) And Inhibibin A. This screening method is more efficient than screening only by age of a pregnant woman, and at the same frequency of invasive interventions (about 5%) makes it possible to identify 50-70% of fruits having trisomy 21.
In the 1990s, a screening method was proposed, based on the age of the mother and the magnitude of the TVP (thickness of the collar space) of the fetus in 11-13 (+6) weeks of pregnancy. This screening method allows to identify up to 75% of fruits with chromosomal pathology at a frequency of false-positive results in 5%. In the subsequent screening method, based on the age of the mother and the magnitude of the fetus, 11-13 (+6) weeks of pregnancy, was supplemented by determining the concentrations of biochemical markers (free fraction β-hCG and RARR-A) in the serum of the mother in the first trimester of pregnancy, What made it possible to identify 85-90% of fruits having trisomy 21.
In 2001, it was found that with an ultrasound study of 11-13 weeks in 60-70% of fruits in the presence of trisomy 21 and in 2% of fruits, with a normal karyotype, nasal bones are not visualized. The inclusion of this marker into the screening method based on ultrasound examination and the definition of biochemical markers in the first trimester of pregnancy allows to increase the frequency of detection of trisomy 21 up to 95%.
What ultrasound - markers, increasing the risk of ha, we evaluate?
First of all, it is an expansion of the thickness of the collar space (TVP), the lack of visualization of the nasal bones, the reverse blood flow in the venous protocol and tricuspid regurgitation.
Collar space - It is an ultrasound manifestation of a cluster of fluid under the skin in the back of the fetal neck in the first trimester of pregnancy.
- The term "space" is used regardless of whether it has a partition space or not whether this space is localized in the neck area or applies to the entire fetus body.
- The frequency of occurrence of chromosomal diseases and malformations of the fetus depends on the value of the TVP, and not from its ultrasound characteristics.
- In the second trimester of pregnancy, the collar space usually disappears or, in rare cases, is transformed or in the neck swelling, or in a cystic hygroma in combination with generalized swelling of the fetus or without any.
1 measurements are made in 11-13 (+6) weeks of pregnancy at the magnitude of the coccicco-dark fetal size from 45 mm to 84 mm. This is an important point, because Not rare on the period of exactly 11 weeks or 11 weeks and 1-2 days the fruit is a couple of millimeters less than 45 mm. This is the option of the norm, but the study in this case will have to be transferred for a week.
2 Measurement should be carried out strictly in the sagittal section of the fetus, with the head of the fetus should occupy a neutral position.
3 The image should be increased so that only the head and the top of the fruit chest and the top of the fetus remain on the screen.
4 The size of the image must be increased in such a way that the minimum cursor displacement gave a resizing by 0.1 mm.
5 The thickness of the collar space should be measured in a wide place. It is necessary to differentiate the fetus skin echostructures and an amniotic shell.
6 cursors must be established on the inner boundaries of echo-empty lines, separating the collar space, not going on it.
7 In the study, it is necessary to measure the TVP several times and select the maximum of the measurements obtained.
In 5-10% of cases, there is a campus of cords around the neck, it can lead to a false increase in TVP. In such cases, the measurement of the TVP should be carried out on both sides of the umbilical source, and to assess the risk of chromosomal pathology of the fetus, the average value of these two dimensions is used.
Visualization of the nasal bones of the fetus
- Must be carried out at a pregnancy term 11-13 (+6) weeks and at the CTR of the fetal of 45-84 mm.
- It is necessary to increase the image of the fetus so that only the head and the top of the fetal body are presented on the screen.
- A strictly sagittal fetal section should be obtained, and the seed plane must be parallel to the plane of the nasal bone.
- When visualizing the nasal bone should be present three separate lines. The top line is the skin of the fruit nose, lower, more echogenic and thick, is a nasal bone. The third line is a continuation of the first, but is slightly higher it and is the tip of the fetus nose.
- In 11-13 (+6) weeks, the fetal profile can be obtained and estimated by more than 95% of the fruit.
- With a normal karyotype, the lack of visualization of nose bones is characteristic of 1% of fruits in women of the European population and for 10% of fruits in women of Afro-Caribbean population.
- Nose bones are not visualized in 60-70% of fruits in trisomy 21, in 50% of fruits in trisomy 18 and in 30% of fruits with trisomy 13.
- At the frequency of false-positive results, 5%, combined screening, including the measurement of the TVP, the visualization of the fetal nose bones and the measurement of the concentration of Rarr-A and β-hgch in the serum of the mother's serum, potentially can identify more than 95% of fruits at trisomy 21.
This fruit is one of the dichorial twins. TVP and blood flow in the venous duct is normal, but there is no visualization of nasal bones. The result of karyotyping - Down syndrome, the karyotype of the 2nd fetus of twins is normal.
Venous ducting dopplerometry and tricuspid regurgitation
In chromosomal anomalies, malformations of various organs and systems are often forming, including congenital defects for the development of the cardiovascular system.
The venous duct is a unique shunt, delivering oxygenated blood from the umbilical vein, which is guided mainly through the oval window into the left atrium, to coronary and brain arteries. The blood flow in the venous duct has a characteristic shape at high speed in the ventricular systole phase (S-wave) and diastoles (D-wave) and orthograde blood flow to the phase of the atrial reduction (A-wave).
In 11-13 (+6) pregnancy weeks, the blood flow disorder in the venous duct is combined with the presence of chromosomal pathology or heart defects and is a sign of a possible adverse outcome of pregnancy. On this period of pregnancy, the pathological form of blood flow velocities is observed in 80% of fruits in trisomy 21 and 5% of the fruits that have normal karyotype.
The tricuspidal regulation is a wave of reverse blood flow through the valve between the right ventricle and the atrium of the heart. In 95% of cases, tricuspid regurgitation, as well as the reverse blood flow in the venous duct, disappears over the next few weeks, as a rule, by 16 weeks; However, in 5% of cases may indicate the presence of a congenital heart defect. In this connection, it is recommended to undergo expanded echocardiography of the fetus in 18-20 weeks.
It is extremely important and it is necessary that the specialists engaged in the risk of chromosomal fruit pathology on the basis of the assessment of its profile have passed appropriate training and certification confirming the level of quality of this type of ultrasound research.
Of course, the screening I trimester is not limited to the definition of ultrasound markers, increasing the risk of a child with such chromosomal anomalies, such as Down syndromes, Edwards, Patau, Turner and Triploidy. Such anomalies of development can also be diagnosed, such as ex bencephaliya and akrany, the vices of limb development and Sireselia, Ommophalcela and Gastrossisis, Megazistis and S-M Prune Belly, anomaly of the body of the body, suspect the dandy Walker and Spina Bifida when changing Sizes IV ventricle, anorectal atresia when detected Pelvic Translucency (pelvic translucency). And this is still not all. I will try to continue to tell about the listed anomalies and defects.
In conclusion, a few words about the procedure of screening I trimester in our center
All specialists of our Center are working on the recommendations of the international organization The Fetal Medicine Foundation (https://www.fetalmedicine.org/) and have certificates of this organization. Fetal Medicine Foundation (FMF), whose supervisor is Professor Kipos Nikyondes, is engaged in research in the field of medicine of the fetus, the diagnosis of anomalies of its development, diagnosis and treatment of various pregnancy complications. Certified specialists and centers are obtained by the developed FMF software for calculating the risk of chromosomal fruit pathology according to ultrasound and biochemical screening. To obtain a certificate for conducting an ultrasound study in 11-13 (+6) weeks, it is necessary to undergo theoretical training on a course supported by FMF; pass practical training in an accredited FMF center; Provide in FMF ultrasonic photos showing the measurement of the fetal TVP, the visualization of the nose bones, the blood flow dopplerometry in the venous dopatory and the tricuspid valve according to the criteria developed by FMF.
After filling out and signing numerous documents and consent on the registry, you will be invited to Uz Cabinet, where I or my colleagues will evaluate the development of the fetus, all the necessary Uz-Markers HA, as well as other possible changes from Chorion, the walls of the uterus and ovaries.
After the study, you will be given a conclusion in two copies and photos of your baby (or babies). One copy of the conclusion you leave, and the second will need to be given in the procedural office, where you will take blood from the vein for the biochemical part of screening. Based on the data of ultrasound and biochemistry, special software will calculate the individual risk of chromosomal pathology of the fetus and after 1-2 days you will receive the result where individual risks will be indicated by the main ha. With your desire, the result can be obtained by email.
In case of obtaining results with low risk of basic Ham, you will be recommended to re-conduct an ultrasound in 19-21 week of pregnancy. If the risk is high, then remember that this is the result of a screening research, and not a diagnosis. To form an accurate diagnosis, consultation of genetics and conducting such diagnostic methods as chorion abion or amniocentesis for prenatal karyotyping is required.
In 2012, another high-precision method of prenatal DNA diagnostics appeared, the uniqueness of which it lies in the fact that it does not require invasive procedures (except for invasion taking blood from the vein pregnant) - Non-invasive prenatal test.
I bring to your attention the table outcomes of pregnancy with an increase in TVP:
As you can see, even with very large TVP, approximately 15% of children can be born healthy, but much more likely that the fetus will have a ha or major developmental abnormalities.
Preparation for research
Biochemical screening is carried out on an empty stomach (4-6 hours of hunger). More often, ultrasound and biochemistry are held on one day, in my opinion, it is very convenient, but if you suddenly got it, you can only pass the ultrasound, and give blood on another day, the main thing is not later than the complete 13 weeks of pregnancy. For ultrasound special training, it is not necessary, but the overcrowded bladder can deliver discomfort to you and the researcher.
In most cases, the ultrasound is carried out transabdomomomomotionally (it is not necessary to undress), but sometimes you have to switch to transvagal research. It is not rare, at the beginning of the study, the position of the fetus does not allow the necessary measurements. In this case, it is necessary to swash, roll over from the side on the side, sometimes even postpone the study for 15-30 minutes. Please assume with understanding.
That's all, see you after 2 weeks!
In obstetrics, the methodology of pregnancy involves a multiple examination of a pregnant woman and the fetus. How many times is screering? Within 9 months, a woman needs to undergo a general survey at different times. It is carried out to evaluate the basic physiological and anatomical characteristics of the fetus and determining the likely pathologies.
The first trimester of pregnancy lasts 14 weeks, the first scheduled survey, consisting of the mandatory first ultrasound of the fetus and various laboratory tests of blood, is appointed by the end of this period.
Order No. 457 min. Health R.F. From 2000, it suggests that screening surveys should be carried out by all pregnant women. Each woman has the opportunity to make a failure. However, such an act can only speak of the illiteracy of the future milf and point to a negligence attitude towards his baby.
How much is the risk factors that are considered a reason for the obligatory conduct of prenatal screening? The main reason for the survey is:
- age criterion: 35+;
- the end of previous pregnancies by miscarriage or fetal fetal;
- professional harm;
- diagnosis of chromosomal pathologies of the fetus in the previous pregnancy or the birth of a child with intrauterine defects of development;
- infectious diseases transferred at the beginning of pregnancy;
- reception for pregnant drugs for pregnant drugs;
- alcoholism, drug addiction;
- diseases transmitted by heredity, both in the family of the mother and in the family of the child's father;
- close related links between the parents of the kid.
Prenatal screening is very important for those women, in the nature of which were genetic diseases or whose child was born with chromosomal disabilities. Screening will provide an opportunity to diagnose pathology of current pregnancy, if necessary - to assign its interruption for medical testimony Conducting a prenatal examination
When is the survey? The main prenatal screening is prescribed at the end of the first trimester. The choice of time is due to the fact that by this time most of the systems and organs of the future child have already formed, and the diagnostic has the opportunity to assess the development of the fetus, to identify pathology in a timely manner. At week 13, ultrasound diagnostics makes it possible to determine the vices of the nervous tube, gene pathologies in the embryo.
Ultrasonic diagnostics, as 1 stage of screening
What surveys includes screening of the first trimester? Screening consists of several types of mandatory diagnostic procedures and analyzes. Ultrasonic fetal diagnosis is the main diagnostic procedure of the first trimester. It is carried out in two ways: transvaginal, that is, the sensor is introduced inside the vagina, or abdominal, that is, through the front abdominal wall.
Ultrasound Screening 1 trimester allows you to determine the anatomical features of the child, the presence of all organs, assess their location and development. The main dimensional fetometric indicators, the characteristics of the correct development of the fetus are also evaluated, the cervical fold, the scalp, biparity diameter, etc. is measured. In mandatory, the magnitude of the smoke-darken size is determined and, accordingly, the approximate growth of the child at this stage of development. With the help of prenatal ultrasonic diagnostics, the quality of placental and umbilical blood flow is estimated, the work of the heart muscle is characterized. Including determine the thickness of the collar space in the fetus, the deviation of this indicator from normal values \u200b\u200bmay indicate a high probability of developing chromosomal pathologies.
The first study of the ultrasound is indispensable in pregnancy, because it gives a doctor the opportunity to remove the first fetometric indicators, determine the level of development of the fetus, its compliance with the term of pregnancy Biochemical examination of blood, like 2 stage of screening
Biochemical blood test is carried out in laboratory conditions. With the help of biochemical testing of blood conducted at week 13, the level of Rarr-A protein and hormone hump is set. This study is called "double test".
The main hormone, which begins to form after the fertilization of the egg, is the chorionic gonadotropin of man. When the hong hong level is low, it indicates that there is placental pathology. The content of the hormone in the blood above the norm speaks of the fruit chromosomal pathologies, or indicates a multiple pregnancy.
The level of plasma protein in the blood of a woman may also indicate various deviations in the development of the embryo. When a significant decrease in RARR-A indicator is noted, this indicates possible chromosomal disorders and other congenital genetic vices.
In the event that the results of the first prenatal screening reveal a high probability of the existence of the described pathological conditions, it is mandatory to assign additional diagnostic procedures. The future mother is directed to the procedure for studying the properties of the accumulating water - amniocentesis. The technique makes it possible to determine the presence of chromosomal pathologies and some genes. Also make chorionobiopsy, i.e. A biopsy of chorionic villi is carried out. To carry out the test, cells forming the placenta take, and with their help, they determine intrauterine and diseases transmitted by heredity.
Preparatory stage Screening
The first screening study needs a preliminary preparatory phase. Prenatal examination in other periods of pregnancy does not require so thorough preparation and is much easier.
What products do not be used before first screening? During the day to research activities, it is recommended to limit the use of products that are potential allergens. This is chocolate, citrus, seafood, individual intolerance products. Doctors do not advise eating fried and oily food.
The first prenatal ultrasound is usually made by a transvaginal method. This diagnostic technique does not require special training. If an abdominal examination is assigned to the testimony - an ultrasound, carried out through the skin of the abdomen, then it is necessary to drink a certain amount of clean water without gas to completely filling the bladder (about 500 ml.).
Preparation for biochemical blood test is quite simple. Screening is made in the morning on an empty stomach, so it is necessary to come against the laboratory. In addition, it is recommended to implement standard hygiene measures before research without using flavored cosmetic and hygiene.
Normal examinations
On the first prenala screening, a number of characteristics are determined and special attention is paid to their compliance with generally accepted standard standards:
- Using ultrasound examination, the thickness of the collar space is estimated (TVP).
- The size of the nasal bone. This indicator, as well as the value of the TVP, allows you to make timely diagnostics of Down syndrome. Up to 11 weeks, it is still impossible to appreciate this anatomical characteristic, and at week 13 the length of the nasal bone should be at least 3 mm.
- The characteristic dependent on the degree of development of the fetus is the frequency of heart abbreviations (CSS). The dependence of the heart rate on the week of pregnancy is given in the table below.
- Also, at ultrasound, the magnitude of the smoke-dark size (CTR) is determined and the calculation of the values \u200b\u200bof the biparity size (BPR) of the child's head is calculated.
At the first ultrasound, the doctor necessarily checks the presence of a nasal bone, calculates the thickness of the collar zone, and also produces other fetometric measurements. All this complex of research and standards allows you to identify genetic deviations and delays in the development in the early stages The normative values \u200b\u200bof the above indicators are presented in a summary table:
| Week of pregnancy | TVP, mm. | CRT, mm. | Heat, strikes per minute | BPR, MM. |
|---|---|---|---|---|
| 10 | 1,5 - 2,2 | 31 – 41 | 161 – 179 | 14 |
| 11 | 1,6 - 2,4 | 42 – 49 | 153 – 177 | 17 |
| 12 | 1,6 - 2,5 | 52 – 62 | 150 – 174 | 20 |
| 13 | 1,7 - 2,7 | 63 – 74 | 147 – 171 | 26 |
Screening of the first trimester of pregnancy includes a mandatory biochemical definition of hormone hong. The normal values \u200b\u200bof this indicator in the female organism correspond to such values:
In addition to the listed indicators on the first prenatal screening, based on the data of the ultrasound, they necessarily evaluate the degree of development of systems and organs of the future child. Using laboratory techniques for blood test, determine the content of glucose and protein A.
Possible pathological states detected by surveys
With the help of ultrasound diagnostics conducted in the first trimester of pregnancy, it is possible to obtain important information about the possible development of chromosomal anomalies.
On the ultrasound, the likelihood of the existence of Down syndrome, de Lange, Patau syndrome, Edwards Syndrome, anomalies in the formation of the nervous system, the appearance of cord hernia and such a chromosomal anomaly, as tripleody.
Decoding Screening data
When deciphering the data obtained on an ultrasound examination and during the study of blood, the doctor compares the results with standard normal values \u200b\u200band calculates the likelihood of possible deviations. For this, the specialist determines the coefficients that show the inconsistency of the data obtained by some standard values. Typically, the resulting coefficient is denoted by the abbreviation of MOM:
- The normal value of MOM for the first 12 - 14 weeks ranges from 0.5 - 2.5. The best one is considered to be 1.
- The value of IOM, calculated for the HCG indicator, is below 0.5, speaks of the high risk of Edwards syndrome. IOM above the value of 2.5 is considered a sign of the development of Down syndrome.
According to the results of the surveys, calculate the general coefficient of the probability of the existence of serious genetic pathologies. In case the amount of the generalized coefficient at week 13 ranges from 1: 251 to 1: 399, this result of the survey is considered poor, and the values \u200b\u200bof the coefficient are considered to be negative indicators below 0.5 and more than 2.5.
The development of two embryos, overweight women, diabetes, or other diseases of the endocrine system can affect screening results, it is allowed to deviate many characteristics from regulatory values. Sometimes even a psychological state affects the accuracy of the data obtained during research.
Unwanted screening results should not be a reason for serious chagrins. As far as high, neither the degree of risk of development of pathology, there is the same high probability of birth of a healthy child.