Transcript of the first ultrasound screening. Screening of the first trimester of pregnancy - what you need to know about rates and results

Content

Referral for a screening examination causes panic in expectant mothers. A lot of questions arise - what is it, is it not dangerous for the baby, why are they sending me? In order not to worry unnecessarily in such a crucial period, it is better to deal with this issue in advance.

What is screening

For women expecting a baby, the Ministry of Health recommends to undergo an examination in the first trimester in order to early dates identify abnormalities in fetal growth. A prenatal checkup does not appear to be threatening for a mother and child. The research price is affordable, so you shouldn't risk the life of your unborn baby. Screening during pregnancy helps to identify:

genetic pathologies;
indirect signs of violations;
fetal malformations.

Everyone who is at risk must be screened during pregnancy in the 1st trimester. These are women who have:

the father of the child who received radiation;
age category over 35;
the threat of termination of pregnancy;
hereditary diseases;
professional harm;
children born with pathologies;
previous frozen pregnancy, miscarriages;
family relationship with the child's father;
drug, alcohol addiction.

First screening during pregnancy

It is important to conduct a screening test for the first time if the price of the issue is the life of the unborn baby. What can be revealed during the survey? First trimester screening can detect:

defects of the central nervous system;
genetic diseases - Edwards, Down syndromes;
the presence of an umbilical hernia;
slow growth of skeletal bones;
disorders of the formation of the brain;
faster or slower heart rate;
one umbilical artery (there should be two).

What they look at at the first screening

Screenings during pregnancy are an important component of the mother's calm state and confidence in the correct development of the baby. Important parameters of the fetus are measured during the first ultrasound examination:

the size between the parietal tubercles;
TVP - dimension of the collar space thickness;
the size of the CTE - from the coccyx to the bone at the crown;
length of bones - forearm, thigh, lower leg, shoulder;
heart size;
Head circumference;
the size of the vessels;
the distance between the frontal, occipital bones;
heart rate.

First screening during pregnancy - timing

What determines the time of the first screening study? An important indicator in the fetus is the thickness of the collar space. The period when the first screening is done is the beginning of 11 weeks, previously the value of TVP is too low. The end of the term is associated with the formation of the fetal lymphatic system. After 14 weeks, the space is filled with fluid, it can increase, as in pathology - and the results will not be objective. The end of the term is considered to be 13 weeks plus an additional 6 days.

Preparing for the 1st trimester screening

An ultrasound examination does not involve preparation if the examination is done through the vagina. The test through the abdominal wall requires filling the bladder with three glasses of water 1.5 hours before starting. How to prepare for the first trimester screening, its second component - a blood test? To obtain an objective result, you need:

two days before, do not eat seafood, nuts, chocolate, smoked and fried foods;
do not drink anything in the morning of the day;
donate blood on an empty stomach.

How to do the first screening during pregnancy

Wanting to exclude defects, to determine the inconsistencies in the development of the fetus, women in the first trimester are sent for examination. After decoding the results, comparing them with the standards, a decision is made. With poor performance, termination of pregnancy is possible. How is the 1st trimester screening going? The research includes two stages:

ultrasound examination, in which measurements of the fetus are made, the characteristics of its vital activity, the state of the uterus are established;
biochemical analysis of maternal blood, revealing the absence of chromosomal defects.

First screening during pregnancy - the norm

After the study, the resulting indicators are compared by specialists with the standards. An important point- the dependence of these values on the correct gestational age: at what exact week the check was carried out. Screening standards for the 1st trimester for ultrasound results are:

coccygeal-parietal size - 34-75 mm;
present, not measured at a period of 11, 12 weeks, nasal bone, further, the value exceeds 3 millimeters;
heart rate - 147-178 beats per minute;
the size between the parietal bones is 13-28 mm;
the thickness of the collar space is in the zone 0.8 - 2.7 mm.

Biochemical hemoanalysis has its own standards. They are influenced by a week of research. After receiving the results, using a computer, the MoM coefficient is calculated, showing the deviations in the development of the fetus. The parameters are proportional to the term:

beta-hCG - 14.2-130.9 ng / ml;
calculated coefficient MoM - 0.51-2.5;
PAPP-A - 046 - 8.53 IU / ml.

Ultrasound screening of the 1st trimester

The main examination of this period is ultrasound. Based on its results (with fears of chromosomal defects), blood tests are prescribed. Screening ultrasound of the 1st trimester checks the fetus, in addition to measuring the parameters:

structure and symmetry of the brain;
venous duct blood flow;
the presence of an umbilical hernia;
position of the stomach, heart;
the number of vessels in the umbilical cord.

During the screening study, measurements and monitoring of the condition of the pregnant woman are carried out. The indicators will tell you about the threats to the development of the fetus. An overestimated uterine tone can provoke a spontaneous abortion. During an ultrasound examination, a woman determines:

location, thickness of the placenta;
uterine tone;
number amniotic fluid;
picture of the cervical pharynx.

Biochemical screening

If abnormalities are detected during ultrasound, blood tests are prescribed to clarify the threat of chromosomal pathologies. The results are interconnected with the timing accurately determined by ultrasound examination. Serum of maternal venous blood is taken for analysis. Based on the results, the risk of anomalies is calculated. Hemotest determines 2 parameters that are compared with the standard:

free beta subunit of hCG;
plasma protein A - PAPP-A.

Screening of the 1st trimester - transcript of the results

Specialists, using computer processing after research, make a transcript of the research. The results of the 1st trimester screening depend on the week in which they are carried out, they have different indicators. When performing an ultrasound scan:

determine the presence and size of the nasal bone - more than 3 millimeters;
measure the thickness of the collar space - an increased indicator indicates the likelihood of pathology.

Deciphering the results of blood biochemistry is also associated with the week in which it is carried out:

beta-hCG indicators are below the standard - the likelihood of an ectopic, frozen pregnancy, miscarriage;
the results are high - toxicosis, the presence of several fetuses, tumors, Down's syndrome are possible;
PAPP-A values are more than normal - the threat of termination, frozen pregnancy;

Video Guide 11 Week First Trimester Screening 001

If the pregnancy proceeds without complications, the mother feels well, then for the first time she will be able to look at her baby during the first screening at about 12 weeks of pregnancy. We will tell you about what a screening study is at this time in this article.

What it is?

There are three screenings for pregnancy. The very first is recommended by the Ministry of Health to be carried out for a period of -13 weeks, 12 weeks are considered optimal. Then the screening study takes place in the second and third trimesters (at 16-24 weeks and at 30-36 weeks).

The examination, which is carried out at the very beginning of the process of carrying a baby, includes Ultrasound, and biochemical blood test for the content of the hCG hormone and the PAPP-A protein. By a number of characteristic markers that are found in the office ultrasound diagnostics, as well as the concentration of hormones and proteins in the analysis of a pregnant woman, a preliminary calculation is made of the risks of a given woman having a baby with incurable and fatal genetic pathologies.

This stage of prenatal diagnosis allows you to identify women who are most likely to have a baby with Down syndrome, Turner and Cornelia de Lange syndromes, Patau syndrome, Edwards syndrome, gross neural tube defects, as well as other developmental anomalies that do not leave the slightest chance for a cure. and a normal life.

Previously, screening was carried out only for those pregnant women who belong to the risk group - women who are already 35 years old and older, who become pregnant from a blood relative, those who have previously had children with genetic problems or women who have relatives with hereditary diseases from your side or from your husband's side. If future mom took medications, which are prohibited during early pregnancy, she was also assigned a screening study.

Now this diagnosis is prescribed to all, without exception, the fair sex in an "interesting position." Of course, for personal reasons, a woman can refuse screening, but it is not entirely reasonable to do this, because the examination itself does not oblige anyone to anything.

It should be noted that based on the results of screening during pregnancy at 12 weeks, no one will make any diagnoses. This is not part of the screening study. A woman will only be calculated the individual risks of giving birth to a sick baby, and whether they are healthy can be determined by other methods that will be recommended by an obstetrician and a geneticist if the risks are high.

The first screening is considered the most important and informative. It is carried out free of charge in a consultation at the place of residence, referrals for a blood test and a coupon to the ultrasound office are issued by a doctor to whom the woman registered for pregnancy.

Procedure and preparation

When undergoing a first trimester perinatal examination, it is very important to follow a strict procedure. Ultrasound diagnostics and blood donation from a vein are planned for one day so that the time interval between these two actions is minimal.

Usually, they first undergo an examination in an ultrasound office, and then, with a completed form, go to the treatment room to donate blood. However, in some consultations, the order is reversed. In any case, both examinations are passed strictly in one day.

So that the test results are not affected by negative factors, which include biochemical changes in the blood, the accumulation of gases in the intestines, a woman is recommended carefully prepare for the diagnosis. For two days, you should go on a short diet - do not eat fatty and very sweet foods, fried and smoked, six hours before the blood test, you should not eat at all. A blood test is taken on an empty stomach.

Before an ultrasound scan, a couple of hours should take "Smecta" or "Espumisan" to get rid of intestinal gases, which are faithful companions of pregnancy, since they can put pressure on the pelvic organs and the results of an ultrasound scan may be inaccurate.

Ultrasound at 12 weeks is performed with a transvaginal probe; the second way - on the stomach, until it gives a clear picture and an idea of what is happening inside the uterus.

On the appointed day, a woman comes to the office of her obstetrician-gynecologist, is weighed, her height is measured and a detailed questionnaire is filled out. The more data it contains, the more accurately the risks will be calculated. The questionnaire includes data on previous pregnancies, miscarriages, abortions, age and weight of a woman, data on her bad habits (smoking, alcohol), information about her husband and the state of health of close relatives.

Then there will be an ultrasound scan, and then blood donation. The general results will be entered into a single form, a special program will "compare" the genetic portrait of the pregnant woman, along with her analyzes, with the "portraits" of women with great risks of giving birth to a sick baby. As a result, an individual calculation will be issued.

Ultrasound procedure

In the ultrasound office, the doctor will examine the baby, determine if everything is fine with him, in which place of the uterine cavity he is entrenched, and also check the baby for markers that show a high probability of having a child with genetic syndromes. At 12 weeks, the expectant mother will be able to see her child, listen to how his little heart beats, and also see the fetal movements that she does not physically feel yet.

The doctor will definitely indicate in the protocol of the first trimester screening study, how many fetuses are visualized in the uterine cavity, do they show signs of vital activity, and also describe the main dimensions that will clarify the timing of the "interesting position" and find out how the development of the crumb proceeds.

The indicators of the rate of development at 12 weeks are as follows:

The fetal head circumference (FH) is 58-84 mm, most often 71 mm.

The coccyx-parietal size (CTE) is 51-59 mm, most often 55 mm.

The biparietal head size (BPD) is 18-24 mm, most often 21 mm.

Heart rate (HR) - 140-170 beats per minute.

Motor activity is present.

In addition, the doctor determines the two most important markers for the diagnosis of genetic pathologies - the thickness of the collar space and the presence of nasal bones in the crumbs. The fact is that in children with gross malformations cervical fold increased due to subcutaneous fluid (swelling), and the nose is flattened. He will be able to consider the rest of the facial bones only after one and a half to two calendar months.

TVP (collar space thickness) at 12 weeks in the absence of pathologies does not go beyond the range of 0.7-2.5 mm. If this parameter is slightly exceeded in the baby, the expectant mother may be advised to undergo an ultrasound scan again in a week. If the TVP significantly exceeds the upper limits of the norm, additional examination will be required, the risks of giving birth to a sick baby increase. We are talking about an excess of 3.0 mm and more.

It is much more difficult to see the nasal bones, they are not always visualized at 12 weeks, the fetus can sit with its back to the doctor's sensor and stubbornly not want to turn around and let its nose be measured. If it was possible to do this, the normal values of the length of the nasal bones at this time are considered to be values that do not go beyond the range of 2.0-4.2 mm.

If the doctor indicated that at 12 weeks these bones are not visualized or their size is less than 2 mm, the program that calculates the risks will increase the individual likelihood of having a baby with Down syndrome, Turner, Patau syndrome.

In fact, a baby may just have a small miniature nose, which is still difficult to capture numerically, especially on an old ultrasound scanner with a low image definition.

Theoretically, at 12 weeks, you can already try to determine the sex of the child, because the external genitals are formed, and if the baby is conveniently located and open to the gaze of the diagnostician, it may well be noticed. However, one should not expect guarantees from the doctor that a boy or a girl will be born. Sex at this time can only be named presumably (the probability of an accurate hit is approximately 75-80%). More precisely, the doctor will assess the baby's sexual characteristics at the next ultrasound scan, after 16-17 weeks of pregnancy.

In addition, at the end of the first trimester, an ultrasound scan evaluates the probable threats of interruption of gestation - thickened uterine walls can indicate the presence of hypertonicity, as well as the condition of the cervix, fallopian tubes, and cervical canal.

Blood chemistry

In the analysis of the venous blood of a pregnant woman, the laboratory assistant identifies the amount of hCG hormone and plasma protein PAPP-A. Because only two blood components are assessed, the first screening test is called a “double test”. The results of this study, in contrast to the ultrasound data, which a woman is given immediately after passing, will have to wait from several days to several weeks - it depends on how long the queue is lined up for research in an accredited medical genetic laboratory.

What numbers will be as a result of the analyzes, one can only guess, since individual laboratories use their own norms in the calculations. To simplify the decoding, it is customary to talk about the norm of PAPP-A and hCG in MoM - a value that is a multiple of the median. At healthy pregnancy, when both the child and the mother are doing well, both values "fit" in the range from 0.5 to 2.0 MoM.

Fluctuations from this range up or down give rise to a lot of experiences in pregnant women and quite a few possible options reasons:

Increasing hCG."Overkill" on this indicator can be a sign of Down syndrome in a baby, as well as a sign that a woman is carrying more than one child. The two fetuses together give a practical double increase in the hormone rate. Increased hCG may be found in a woman who is overweight, edema, toxicosis, diabetes and hypertension.

Lowering hCG. An insufficient level of this hormone, inherent only in pregnant women, is characteristic of the development of Edwards syndrome, and can also indicate the likelihood of a miscarriage or a delay in the development of the baby.

Lowering the PAPP-A. A decrease in plasma protein in the sample sometimes indicates the development of conditions such as Down, Patau, Edwards, Turner syndromes. Also, an insufficient amount of this substance often speaks of malnutrition of the baby, that the baby is deficient in nutrients and vitamins that it needs for normal development.

Raising PAPP-A. The increase in protein in the sample is not of great diagnostic value in terms of calculating the possible risk of chromosomal abnormalities. This indicator may be higher than normal with twins or triplets, as well as with a tendency to a large fetus.

How are risks calculated?

The results of analyzes and ultrasound, as well as all available information about the health of the pregnant woman and her age are loaded into a special program. Thus, the calculation of the individual risk is carried out by the machine, but the result is rechecked by a person - a geneticist.

By a combination of factors, the individual the risk can look like a ratio of 1: 450 or 1: 1300 for each disease. In Russia, the risk is considered high 1: 100. The threshold risk is 1: 101 - 1: 350. Thus, if a pregnant woman was counted the probability of having a baby with Down syndrome 1: 850, this means that one in 850 children has women with identical health indicators , age and other criteria will be born sick. The rest 849 will be born healthy. This is a low risk, no need to worry.

Women for whom screening diagnostics at 12 weeks shows a high risk for a particular genetic disease are recommended additional diagnostics, since the screening itself cannot be considered a basis for a final verdict, it is not that accurate. A non-invasive DNA test can be done. Such an analysis costs several tens of thousands of rubles and is done exclusively in medical genetic centers and clinics.

If the analysis confirms the suspicions, then you still have to go for an invasive test.

Amniocentesis or chorionic biopsy can be offered immediately, without spending time and money on examining the baby's blood cells isolated from the mother's blood, as is done with a non-invasive DNA test. However, both biopsy and amniocentesis involve penetration into the membranes to collect material for analysis. The procedure is carried out under ultrasound control only experienced doctors, however, the risk that the fetus will become infected, the outpouring of water, the termination of pregnancy still remains.

Agreeing or not agreeing to undergo an invasive examination at high risks is a private matter for every woman, no one can force her to do it. The accuracy of the analysis is 99.9%. If disappointing assumptions are confirmed, the woman is given a referral to terminate the pregnancy for medical reasons. It is also up to the woman and her family to decide whether to interrupt it or not.

If it is decided to leave the child, the woman will still have enough time to prepare for the birth of a “special” baby.

What's happening
Fetal development
Screening

Almost every pregnant woman has heard something about the screening of the first trimester of pregnancy (prenatal screening). But often even those who have already passed it do not know what exactly it is prescribed for.

And to expectant mothers who have yet to do this, this phrase in general sometimes seems frightening. And it scares only because the woman does not know how to do it, how to interpret the results obtained later, why the doctor needs it. You will find answers to these many other questions related to this topic in this article.

So, more than once I had to deal with the fact that a woman, upon hearing an incomprehensible and unfamiliar word screening, began to draw terrible pictures in her head that frightened her, making her want to refuse to carry out this procedure. Therefore, the first thing we will tell you is what the word "screening" means.

Screening (English screening - sorting) is different methods studies, which, due to their simplicity, safety and availability, can be used en masse in large groups of people to identify a number of signs. Prenatal means prenatal. Thus, we can give the following definition of the concept of "prenatal screening".

Screening of the first trimester of pregnancy is a complex of diagnostic studies used in pregnant women at a certain stage of pregnancy to identify gross malformations of the fetus, as well as the presence or absence of indirect signs of fetal pathologies or genetic abnormalities.

The allowable period for screening 1 trimester is 11 weeks - 13 weeks and 6 days (see). Earlier or later, screening is not carried out, since in this case the results obtained will not be informative and reliable. The most optimal period is considered to be 11-13 obstetric weeks pregnancy.

Who is referred for first trimester screening?

According to order No. 457 of the Ministry of Health Russian Federation since 2000, prenatal screening is recommended for all women. A woman can refuse it, no one will forcibly lead her to these studies, but it is extremely reckless to do this and speaks only of the woman's illiteracy and negligence towards herself and, above all, towards her child.

Risk groups for whom prenatal screening should be mandatory:

Women aged 35 and over.
The presence of a threat of early termination of pregnancy.
History of spontaneous miscarriage (s).
History of freezing (s) or regressing (s) pregnancy (s).
The presence of occupational hazards.
Previously diagnosed chromosomal abnormalities and / or malformations in the fetus based on the results of screening in past pregnancies, or the presence of children born with such abnormalities.
Women who have had an infectious disease in early pregnancy.
Women who took drugs prohibited for use by pregnant women in early pregnancy.
The presence of alcoholism, drug addiction.
Hereditary diseases in the family of a woman or in the family of the child's father.
I am closely related to the relationship between the mother and the father of the child.

Prenatal screening at 11-13 weeks of gestation consists of two research methods - ultrasound screening for the 1st trimester and biochemical screening.

Screening ultrasound

Preparation for research: If ultrasound is performed transvaginally (the sensor is inserted into the vagina), then special preparation is not required. If ultrasound is performed transabdominal (the sensor is in contact with the anterior abdominal wall), then the study is performed with a full bladder. To do this, it is recommended not to urinate 3-4 hours before it, or an hour and a half before the study, drink 500-600 ml of water without gas.

Prerequisites for obtaining reliable ultrasound data... According to the standards, screening of the first trimester in the form of ultrasound is carried out:

No earlier than 11 obstetric weeks and no later than 13 weeks and 6 days.
CTE (coccygeal-parietal size) of the fetus is not less than 45 mm.
The position of the child should allow the doctor to adequately carry out all measurements, otherwise, it is necessary to cough, move, walk for a while for the fetus to change its position.

As a result of ultrasound the following indicators are investigated:

CTE (coccygeal-parietal size) - measured from the parietal bone to the coccyx
Head circumference
BPR (biparietal size) - the distance between the parietal tubercles
Distance from the frontal bone to the occipital bone
Symmetry of the cerebral hemispheres and its structure
TVP (collar space thickness)
Heart rate (heart rate) of the fetus
The length of the humerus, femur, as well as the bones of the forearm and lower leg
Location of the heart and stomach in the fetus
The size of the heart and large vessels
Placenta location and thickness
Water quantity
The number of vessels in the umbilical cord
The state of the internal os of the cervix
The presence or absence of uterine hypertonicity

Decryption of the received data:

What pathologies can be detected as a result of ultrasound?

According to the results of ultrasound screening of the 1st trimester, we can talk about the absence or presence of the following anomalies:

- trisomy 21 chromosome, the most common genetic disease. The prevalence of detection is 1: 700 cases. Thanks to prenatal screening, the birth rate of children with Down syndrome has dropped to 1 in 1100 cases.
Neural tube pathologies(meningocele, meningomyelocele, encephalocele and others).
Omphalocele is a pathology in which part internal organs located under the skin of the anterior abdominal wall in the hernial sac.
Patau syndrome - trisomy on chromosome 13. The frequency of occurrence is on average 1: 10,000 cases. 95% of children born with this syndrome die within a few months due to severe damage to internal organs. Ultrasound - rapid fetal heartbeat, impaired development of the brain, omphalocele, slowing down the development of tubular bones.
- trisomy on chromosome 18. The frequency of occurrence is 1: 7000 cases. It is more common in children whose mothers are over 35 years old. On ultrasound, there is a decrease in the fetal heart rate, omphalocele, the nasal bones are not visible, one umbilical artery instead of two.
Triploidy is a genetic abnormality in which there is a triple set of chromosomes, instead of a double set. It is accompanied by multiple fetal malformations.
Cornelia de Lange syndrome- a genetic abnormality, in which the fetus has various developmental defects, and in the future, mental retardation. The frequency of occurrence is 1: 10,000 cases.
Smith-Opitz Syndrome- an autosomal recessional genetic disease manifested by metabolic disorders. As a result, the child has multiple pathologies, mental retardation, autism and other symptoms. The frequency of occurrence is on average 1: 30,000 cases.

More about Down's Syndrome Diagnosis

Mainly, ultrasound examination at 11-13 weeks of gestation is performed to detect Down syndrome. The main indicator for diagnosis is:

Collar space thickness (TVP). TVP is the distance between soft tissues neck and skin. An increase in the thickness of the collar space may indicate not only an increased risk of having a baby with Down syndrome, but also that other genetic pathologies in the fetus are possible.
In children with Down syndrome, the nasal bone is most often not visualized at 11-14 weeks. The contours of the face are smoothed out.

Up to 11 weeks of gestation, the thickness of the collar space is so small that it is impossible to adequately and reliably estimate it. After 14 weeks, the fetus develops a lymphatic system and this space can normally be filled with lymph, so the measurement is also not reliable. The incidence of chromosomal abnormalities in the fetus, depending on the thickness of the collar space.

When decoding the screening data for the 1st trimester, it should be remembered that only one indicator of the thickness of the collar space is not a guide to action and does not speak of a 100% probability of having a disease in a child.

Therefore, the next stage of screening for the 1st trimester is carried out - taking blood to determine the level of β-hCG and PAPP-A. Based on the obtained indicators, the risk of the presence of chromosomal pathology is calculated. If the risk based on the results of these studies is high, then amniocentesis is suggested. This is the collection of amniotic fluid for a more accurate diagnosis.

In especially difficult cases, cordocentesis may be required - taking the umbilical cord blood for analysis. Chorionic villus sampling may also be used. All of these methods are invasive and carry risks to the mother and fetus. Therefore, the decision to conduct them is decided by the woman and her doctor together, taking into account all the risks of carrying out and refusing the procedure.

Biochemical screening of the first trimester of pregnancy

This stage of the study is carried out necessarily after an ultrasound scan. This is an important condition, because all biochemical parameters depend on the gestational age up to the day. Every day, the rates of indicators change. And ultrasound allows you to determine the duration of pregnancy with the accuracy that is necessary for the correct study. At the time of donating blood, you should already have the results of an ultrasound scan with the indicated gestational age based on the CTE. Also, ultrasound may reveal a frozen pregnancy, regressing pregnancy, in which case further examination does not make sense.

Preparation for research

Blood sampling is performed on an empty stomach! It is undesirable to even drink water in the morning of this day. If the examination is carried out too late, some water may be drunk. It is better to take food with you and have a bite to eat immediately after taking blood than to violate this condition.

2 days before the appointed day of the study, you should exclude from the diet all foods that are strong allergens, even if you have never been allergic to them - these are chocolate, nuts, seafood, as well as very fatty foods and smoked meats.

Otherwise, the risk of getting unreliable results increases significantly.

Let us consider what deviations from the normal values of β-hCG and PAPP-A may indicate.

β-hCG - chorionic gonadotropin

This hormone is produced by the chorion ("shell" of the fetus), thanks to this hormone, it is possible to determine the presence of pregnancy in the early stages. The level of β-hCG gradually increases in the first months of pregnancy, its maximum level is observed at 11-12 weeks of pregnancy. Then the level of β-hCG gradually decreases, remaining unchanged throughout the second half of pregnancy.

Normal indicators of the level of chorionic gonadotropin, depending on the duration of pregnancy:		An increase in the level of β-hCG is observed in the following cases:	A decrease in the level of β-hCG is observed in the following cases:
Weeks	β-hCG, ng / ml	Down Syndrome Multiple pregnancy Severe toxicosis Diabetes mellitus in the mother	Edwards syndrome Ectopic pregnancy (but this is usually established before biochemical examination) High risk of termination of pregnancy
10	25,80-181,60
11	17,4-130,3
12	13,4-128,5
13	14,2-114,8

PAPP-A - Pregnancy Associated Protein-A

This protein, produced by the placenta in the body of a pregnant woman, is responsible for the immune response during pregnancy and is also responsible for the normal development and functioning of the placenta.

MoM coefficient

After receiving the results, the doctor evaluates them by calculating the MoM coefficient. This coefficient shows the deviation of the level of indicators for a given woman from the average normal value. Normally, the MoM-coefficient is 0.5-2.5 (with multiple pregnancy up to 3.5).

The data of the coefficient and indicators may differ in different laboratories, the level of the hormone and protein can be calculated in other units of measurement. You should not use the data in the article as norms for your research. It is necessary to interpret the results together with your doctor!

Further, using the PRISCA computer program, taking into account all the indicators obtained, the woman's age, her bad habits (smoking), the presence diabetes mellitus and other diseases, the woman's weight, the number of fetuses or the presence of IVF - the risk of having a child with genetic abnormalities is calculated. A high risk is a risk of less than 1 in 380.

Example: If the report indicates a high risk of 1: 280, this means that out of 280 pregnant women with the same indicators, one will have a child with a genetic pathology.

Special situations where the indicators may be different.

IVF - β-hCG values will be higher, and PAPP-A values will be below average.
When a woman is obese, hormone levels may rise.
With multiple pregnancies, β-hCG is higher and the norms for such cases have not yet been established accurately.
Diabetes mellitus in a mother can cause hormone levels to rise.

Screening of the 1st trimester is a diagnostic study that is carried out for pregnant women at risk from 10 to 14 weeks. It, being the first of two screening observations, allows you to determine with great accuracy how high the risk of having a sick fetus is. Such an examination consists of two parts - blood donation from a vein and an ultrasound scan. Based on them, taking into account many of your individual factors, the geneticist makes his verdict.

Screening (from the English. "Screening") is a concept that includes a number of measures for the detection and prevention of diseases. For example, screening during pregnancy provides the doctor with complete information about the various risks of pathologies and complications in the development of the child. This makes it possible to take in advance the full range of measures to prevent diseases, including the most severe ones.

Who needs to be screened for the 1st trimester

It is very important that the following women undergo the study:

closely related to the child's father
who have had 2 or more miscarriages (preterm birth)
had a frozen pregnancy or stillbirth
the woman has had a viral or bacterial disease during pregnancy
there are relatives suffering from genetic pathologies
this couple already has a child with Patau syndrome, Down syndrome or others
there was an episode of treatment with drugs that cannot be used during pregnancy, even if they were prescribed for vital signs
pregnant over 35 years old
both parents-to-be want to check the likelihood of a sick fetus being born.

What are looking for at the first ultrasound screening during pregnancy

What do they look at at the first screening? The length of the embryo is assessed (this is called the coccygeal-parietal size - CTE), the size of the head (its circumference, biparietal diameter, the distance from the forehead to the back of the head).

The first screening shows the symmetry of the cerebral hemispheres, the presence of some of its structures, which are mandatory in this period. Look at 1 screening also:

long tubular bones, the length of the humerus, femur, forearm and lower leg is measured
whether the stomach and heart are in certain places
the size of the heart and the vessels outgoing from them
the size of the abdomen.

What pathology does this examination reveal?

The first pregnancy screening is informative in terms of detecting:

pathology of the rudiment of the central nervous system - neural tube
Patau syndrome
omphalocele - an umbilical hernia, when a different number of internal organs are located outside the abdominal cavity, and in the hernial sac above the skin
Down syndrome
triploidy (triple set of chromosomes instead of double)
Edwards syndrome
Smith-Opitz syndrome
de Lange syndrome.

The timing of the study

When should the first screening be done? The timing of the diagnosis of the 1st trimester is very limited: from the first day of the 10th week to the 6th day of the 13th week. It is better to do the first screening in the middle of this range, at 11-12 weeks, since the error in the calculations significantly reduces the accuracy of the calculation.

Your doctor should once again scrupulously and thoroughly, depending on the date of the last menstruation, calculate how long you should undergo the first examination of this kind.

How to prepare for the study

First trimester screening is done in two stages:

First, an ultrasound screening is done. If this is done transvaginally, then no preparation is required. If by the abdominal method, then it is necessary that the bladder is full. To do this, you need to drink half a liter of water half an hour before the study. By the way, the second screening during pregnancy is carried out transabdominally, but does not require preparation.
Biochemical screening. This word is called the collection of blood from a vein.

Given the two-stage study, preparation for the first study includes:

filling Bladder- before 1 ultrasound screening
fasting at least 4 hours before taking blood from a vein.

In addition, a diet is needed before the diagnosis of the 1st trimester in order for the blood test to give an accurate result. It consists in excluding the intake of chocolate, seafood, meat and fatty foods the day before you plan to attend a screening ultrasound scan during pregnancy.

If you plan (and this is the best option for perinatal diagnostics of the 1st trimester) to undergo ultrasound diagnostics and donate blood from a vein in one day, you need:

all the previous day, deny yourself allergenic products: citrus fruits, chocolate, seafood
exclude completely fatty and fried foods (1-3 days before the study)
before the study (usually blood is donated for screening for 12 weeks before 11:00) go to the toilet in the morning, then either not urinate for 2-3 hours, or an hour before the procedure, drink half a liter of water without gas. This is necessary if the study will be performed through the abdomen.
if ultrasound diagnostics is done with a vaginal probe, then preparation for the 1st trimester screening will not include filling the bladder.

How the research is done

How is the study for malformations done in the 1st trimester?

It, like the examination of 12 weeks, consists of two stages:

Ultrasound screening during pregnancy. It can be performed both vaginally and through the abdomen. It doesn't feel any different from an ultrasound scan at 12 weeks. The difference is that it is performed by sonologists who specialize specifically in prenatal diagnostics, using high-class equipment.
Blood sampling from a vein in an amount of 10 ml, which should be carried out on an empty stomach and in a specialized laboratory.

How is the 1st trimester screening diagnostics carried out? First, you have your first pregnancy ultrasound. It is usually performed transvaginally.

Decoding the results

1. Normal ultrasound data

Deciphering the first screening begins with the interpretation of the ultrasound diagnostic data. Ultrasound standards:

Coccygeal-parietal size (CTE) of the fetus

When screened at 10 weeks, this size is in the following range: from 33-41 mm on the first day of 10 weeks to 41-49 mm - on 6 days of 10 weeks.

Screening at 11 weeks - CTE norm: 42-50 mm on the first day of 11 weeks, 49-58 - on its 6th day.

During pregnancy of 12 weeks, this size is: 51-59 mm at 12 weeks exactly, 62-73 mm - on the last day of this period.

2. Thickness of the collar area

1 trimester ultrasound rates for this most important marker of chromosomal pathologies:

at 10 weeks - 1.5-2.2 mm
screening for 11 weeks is represented by a norm of 1.6-2.4
at week 12, this figure is 1.6-2.5 mm
at 13 weeks - 1.7-2.7 mm.

3. Nasal bone

Deciphering an ultrasound scan of the 1st trimester necessarily includes an assessment of the nasal bone. This is a marker, thanks to which it is possible to assume the development of Down syndrome (for this, screening of the 1st trimester is done):

at 10-11 weeks, this bone should already be detected, but its size has not yet been estimated
screening at 12 weeks or one week later shows that this bone is at least 3 mm normal.

4. Heart rate

at 10 weeks - 161-179 beats per minute
at 11 weeks - 153-177
at 12 weeks - 150-174 beats per minute
at 13 weeks - 147-171 beats per minute.

5. Biparietal size

The first screening study during pregnancy assesses this parameter depending on the period:

at 10 weeks - 14 mm
11 - 17 mm
screening for 12 weeks should show a result of at least 20 mm
at 13 weeks BPD is 26 mm on average.

According to the results of ultrasound of the 1st trimester, it is assessed whether there are markers of fetal anomalies. It also analyzes what period the baby's development corresponds to. At the end, a conclusion is made whether it is necessary to conduct the next screening ultrasound in the second trimester.

You can ask to have a 1-trimester ultrasound video recorded. You also have every right to get a photo, that is, a printout of the image that is either the most successful (if everything is normal), or most clearly demonstrates the pathology found.

What are the norms of hormones determined by 1 screening

First trimester screening not only evaluates the results of ultrasound diagnostics. The second, no less important stage, by which it is judged whether the fetus has serious defects, is a hormonal (or biochemical) assessment (or a blood test in the 1st trimester). Both of these steps constitute genetic screening.

1. Chorionic gonadotropin

This is the hormone that stains the second strip on your home pregnancy test. If the first trimester screening reveals a decrease in its level, this indicates a pathology of the placenta or an increased risk of Edwards syndrome.

Elevated hCG at the first screening may indicate an increased risk of developing Down syndrome in the fetus. Although with twins, this hormone is also significantly increased.

First screening during pregnancy: the rate of this hormone in the blood (ng / ml):

10 weeks: 25.80-181.60
11 week: 17.4-130.3
decoding of the perinatal study of the 1st trimester at 12 weeks relative to hCG shows a figure of 13.4-128.5 is normal
at 13 weeks: 14.2-114.8.

2. Pregnancy Associated Protein A (PAPP-A)

This protein is normally produced by the placenta. Its concentration in the blood increases with the duration of pregnancy.

How to understand the data

The program, into which the data of ultrasound diagnostics of the first trimester, as well as the level of the above two hormones, are entered, calculates the analysis indicators. These are called "risks." At the same time, the decoding of the results of screening for the 1st trimester is written in the form not in the level of hormones, but in such an indicator as "MoM". This is a coefficient that shows the deviation of the value for a given pregnant woman from a certain calculated median.

To calculate MoM, divide the indicator of a hormone by the median value calculated for a given area for a given gestational age. MoM norms at the first screening are from 0.5 to 2.5 (with twins, triplets - up to 3.5). The ideal MoM value is close to "1".

Are there risks in research

Normally, the results of the 1st trimester diagnosis end with a risk assessment, which is expressed as a fraction (for example, 1: 360 for Down's syndrome) for each syndrome. It is this fraction that reads like this: in 360 pregnancies with the same screening results, only 1 baby is born with Down's pathology.

Deciphering the standards of screening for the 1st trimester. If the child is healthy, the risk should be low and the screening test result should be described as “negative”. All numbers after the fraction must be large (greater than 1: 380).

Poor first screening is characterized by a "high risk" entry in the conclusion, a level of 1: 250-1: 380, and the results of hormones are less than 0.5 or more than 2.5 median values.

If the 1st trimester screening is poor, you are asked to visit a geneticist who decides what to do:

schedule you to re-test in the second, then - screening for the 3rd trimester
offer (or even insist) on an invasive diagnosis (chorionic villus sampling, cordocentesis, amniocentesis), on the basis of which the question of whether this pregnancy should be prolonged will be decided.

What affects the results

As with any study, there are false positive results from the first perinatal study. So, for:

IVF: the results of hCG will be higher, PAPP - 10-15% lower, the indicators of the first screening ultrasound will increase the LHR
obesity of the expectant mother: in this case, the levels of all hormones increase, while with low body weight, on the contrary, they decrease
screening for 1 trimester for twins: the rate of results for such a pregnancy is not yet known. Therefore, risk assessment is difficult; only ultrasound diagnostics is possible
diabetes mellitus: the 1st screening will show a decrease in the level of hormones, which is not reliable for the interpretation of the result. In this case, pregnancy screening may be canceled.
amniocentesis: the rate of perinatal diagnosis is not known if the manipulation was carried out within the next week before donating blood. It is necessary to wait a longer period after amniocentesis before undergoing the first perinatal screening of pregnant women.
the psychological state of the pregnant woman. Many people write: "I'm afraid of the first screening." It can also affect the result, and unpredictably.

Some features in pathology

The first screening of pregnancy in fetal pathology has some features that doctors of ultrasound diagnostics see. Consider perinatal screening for trisomies as the most common pathologies detected by this examination.

1. Down syndrome

in most fetuses, the nasal bone is not visible at 10-14 weeks
from 15 to 20 weeks, this bone is already visualized, but it is shorter than normal
smoothed out the contours of the face
with dopplerometry (in this case, it can be performed even in this period), a reverse or other pathological blood flow in the venous duct is noted.

2. Edwards syndrome

tendency to decrease the heart rate
have an umbilical hernia (omphalocele)
no visible bones of the nose
instead of 2 arteries of the umbilical cord - one

3. Patau syndrome

almost everyone has heart palpitations
impaired development of the brain
the development of the fetus is slowed down (inconsistency of the lengths of the bones with the term)
violation of the development of some parts of the brain
umbilical hernia.

Where to study

Where is the 1st trimester screening done? Many perinatal centers, genetic counseling centers and private clinics are conducting this study. To choose where to get screening, see if there is a laboratory in or near the clinic. It is recommended to take it in such clinics and centers.

For example, in Moscow, the CIR has proven itself well: it conducts and screening of the 1st trimester can be done in this Center.

Ultrasound screening of the 1st trimester: the average price is 2,000 rubles. The cost of the first perinatal study (with the determination of hormones) is about 4000-4100 rubles.

How much does screening for the 1st trimester cost by type of test: ultrasound - 2000 rubles, determination of hCG - 780 rubles, analysis for PAPP-A - 950 rubles.

Medicine operates with a wide arsenal of terms, the meaning of which is unknown to us. But sometimes these words-names become a part of our life, since doctors prescribe certain procedures, drugs and research to us. Among them, and. What is it? How is it used? For what purpose? Let's look at a specific example.

Screening: what, where, when?

The word "screening" comes from the English screening - "sifting". This is the name of the methods of special checks and examinations, which are used not only in medicine, but also in biochemistry, business and other spheres of life.

Medical screening is the conduct of safe special studies in order to identify the risk of developing a certain pathology. In other words, screening is a method for determining a specific disease or factors contributing to it (). To conduct a screening, a screening examination is done, that is, testing.

Screening as a research method is used in various fields of medicine. For example, in genetics - for the timely detection of inherited diseases. And in this area, the most successful was the identification of genetically determined metabolic disorders.

In cardiology, this research method is used to identify ischemia, arterial hypertension and risk factors that contribute to the development of these diseases.

As for the methodological screening procedure, it can be one-step or consist of several stages. Repeated screening studies make it possible to assess the stability of the indicators that are being studied.

It should be noted that screening is not a mandatory procedure for the patient. For medical personnel, screening studies enable physicians to identify patterns in human health. By observing medical statistics based on screening, scientists defend dissertations.

What is pregnancy screening?

Since screening is of great importance for pregnant women and the health of the future nation, we will consider in detail how it is carried out. Prenatal screening is done to expectant mothers to identify risk groups for complications of bearing a child. It makes it possible to identify pregnant women at risk of giving birth to babies with Down syndrome or Edwards, anencephaly.

The first screening for the expectant mother is prescribed in a period of 11 to 14 weeks. With the help of ultrasound, the thickness of the collar space of the unborn child is measured, its approximate age is calculated and the PDD (preliminary date of birth) is specified. In addition to ultrasound, a pregnant woman donates blood for 2 hormones. This is the so-called double test. The first screening makes it possible to exclude the unborn baby.

A second screening is given to a pregnant woman between 16 and 18 weeks. At this stage, it is only possible to pass the triple test.

All data of the doctor is entered into computer program to calculate possible risks.

The expectant mother is given a special sheet with the results of the screening examination. If it is done in the direction of the attending physician of a pregnant woman, the results usually wait for three weeks. When a woman is screened at a paid clinic, she gets results much faster - in 2-3 days. This leaflet indicates whether all indicators fit into the norm, whether there is a threat of termination of pregnancy and congenital defects fetal development. A doctor observing a woman, having such a sheet in her hands, will competently and easily explain to her patient how her pregnancy is going, and if there are risks, then he will definitely prescribe treatment.

If a high risk of having an inferior child is identified, the expectant mother is sent for a consultation with a geneticist. After carefully reading the information on the sheet, he additionally asks the woman about the genetic predisposition to certain diseases, that is, about hereditary diseases... And a pregnant woman should know this information. It is very important to communicate with your mother, the mother of the spouse in order to avoid the risks of giving birth to a defective child. After such a conversation, the geneticist gives the woman a conclusion about the likelihood of the future baby's defects. If the risk is high, the doctor may offer the woman an invasive examination, for example, an analysis of the amniotic fluid. This is a rather risky manipulation that must be performed by a qualified doctor. The result of an invasive study will clear up all doubts.

So, screening is an important medical research that is informative and preventive in nature. Aware of the risks means armed. Therefore, you should not give up this procedure, which has long ceased to be an innovation, it helps doctors and patients.

Specially for Elena TOLOCHIK