1st screening during pregnancy timing. Prenatal screening - the most complete information. How is ultrasound screening done in a perinatal center

16.07.2017 18

Medicine is improving every year. A few decades ago, for a pregnant woman, the mystery remained until the moment of the birth itself. Now it has become possible not only to find out the sex of the child, but also to find out about the possibility of his congenital diseases.

Prenatal means "prenatal", that is, during pregnancy. Screening literally translates as "sifting". In simple terms, the procedure eliminates cases with a high risk of birth defects.

If one is found, then this is the basis for termination of pregnancy. However, the final decision always remains with the woman.

What's happening?

You can, of course, do without it, but you should know that it allows you to get more accurate results. They, in turn, will help the doctor with a high probability to make or refute any diagnosis.

Ultrasound in the 1st trimester can be performed by two methods: abdominal and vaginal.

It should be noted that the baby is growing daily. Therefore, the indicators obtained at 10 and 14 weeks will be very different. You should not compare your values ​​​​with the measurements of a friend or neighbor. Better pay attention to the rules:

• at the beginning of the 10th week, the CTE is 3-4 mm, and at the beginning of the next - 5 mm;
• at week 11, this figure should be in the range from 4.2 to 5.8 mm;
• exactly at 12 weeks, the CTE varies in different women from 5 to 6 mm, and at 13 weeks it can reach 7.5 mm.

Collar zone

Always considered. It is he who can point out deviations and make the doctor suspect congenital pathologies. The following values ​​indicate the absence of chromosomal abnormalities:

• at 10 weeks TVP from 1.5 to 2.2 mm;
• at 11 weeks - up to 2.4 mm;
• at 12 weeks, the value is from 1.6 to 2.5 mm;
• and at week 13 it is 1.7–2.7 mm.

nasal bone

If during the screening of the 1st trimester it turns out that there is no nasal bone, then this may be one of the signs of Down syndrome. This indicator is the second most important after the TVP.
· At 10-11 weeks' gestation, the nasal bone is normally detectable but not yet measurable. In this case, the sonologist simply indicates the presence of this indicator.
At 12 weeks and later, the nasal bone has a size of 3 mm. Therefore, this period is most often chosen for ultrasound of the first trimester of pregnancies.

The work of the heart

Determines the state of this important organ. It also changes over time. Here are the main rules:

• 10 weeks - 161-180 bpm;
• 11 weeks - 152-178 bpm;
• 12 weeks - 149-173 beats / min;
• 13 weeks - 146-170 beats / min.

Decryption

If at least one indicator of ultrasound diagnostics does not correspond to normal parameters, then the doctor will prescribe an additional examination. Its appearance depends entirely on what result was obtained initially.

For example, if the size of the fetus does not match, but the blood counts are good and there are no deviations in the TVP, an additional ultrasound is prescribed. There is a possibility that the first study was conducted with an error. If congenital anomalies are suspected (corresponding blood values ​​and deviations from the norms of the nasal bone and TVP), then an amniocentesis may be offered to the woman.

It is important to be aware of the consequences of taking amniotic fluid, which can be very deplorable. Also, the gynecologist can prescribe, for which certain terms and norms are also established.

How right? If you do not have a medical education, then you will not be able to independently evaluate the information received. To do this, you should contact a gynecologist or reproductive specialist.

Based on ultrasound diagnostics and blood counts, a fractional value is compiled, which shows the risk of deviations. If it is minimal or tends to zero, then you will see the word "negative".

When the risk is higher, numerical fractions are put, for example, 1:370, which may mean Down syndrome in a child. A poor result and a high risk are reported by values ​​in the range from 1:250 to 1:380.

Additionally

It is important to know that screening values ​​can be affected by several factors. When evaluating the result and decoding, the doctor must take into account those.

• When blood counts can be changed. At the same time, according to ultrasound, everything fits within the normal range.
• Excess or deficiency of body weight leads to a shift in the value of hormones in the appropriate direction. Ultrasound signs remain normal.
• Multiple pregnancy rarely acquires standard blood counts. On ultrasound in babies, the values ​​\u200b\u200bremain normal, but may be underestimated.
• In women after 35 years, the risk may be overestimated due to individual characteristics.

What does it say about Down syndrome?

• The fetus is missing a nasal bone or cannot be measured after 12 weeks.
• The facial contours are smoothed out more than in other children (can only be detected with the help of modern equipment.
• Pathological blood flow in the duct, detected by dopplerometry.

How to recognize Edwards syndrome?

• The fetal heart has a slow rhythm, reduced heart rate.
• A hernia is found in the umbilical cord.
• The nasal bones are not visualized at any time.
• The umbilical cord has only one artery instead of two.
• Indicators of Patau Syndrome
• Unusually fast heartbeat.
• Are present.
• The growth of the embryo is impaired, small bones are noted.
• Hernia in the region of the umbilical cord.

Let's summarize

Screening in the first trimester is very important for assessing the condition of the fetus. Some pathologies that are now established can be corrected already during pregnancy.

To detect them, they do an ultrasound. Other abnormalities require medical intervention immediately after childbirth (for example, heart disease).

There are anomalies that are incompatible with life or promise the birth of a disabled child. In such situations, a woman will have to make an important decision about whether to continue the pregnancy or terminate it.

We must not forget that there is a risk of errors, although it is small. Be sure to double-check the indicators if they turned out to be inconsistent with the standards.

Ultrasound screening is a complete set of examinations that allows mom and dad to find out about the health status of a baby in the womb. This method allows you to see the presence or absence of many congenital diseases. Usually it is done three times during pregnancy - in the first, second and third trimester. It consists of two procedures - ultrasound diagnostics and blood tests.

First trimester screening consists of ultrasound and blood test

The first screening is done between 11 and 14 weeks after conception. The main objective of the method is to check the fetus for the presence of any pathologies in development.

This method of verification even reveals complications in pregnancy, which the expectant mother might not have been aware of due to the absence of symptoms, good health, etc. This study is not always made pregnant, often other groups of people undergo it.

For example, screening a group of children of the same age - the technique allows you to identify characteristic diseases for this age. Since it is usually prescribed only three times, it scares women if a specialist sends for additional screening.

There is no reason to panic, because doctors are sent for an additional examination not because of the detection of a pathology, but because there is a risk of its development. For example, screening is often prescribed for women over 35 years old if family members have pathologies, if there was a miscarriage or miscarriage in the past, etc.

How is the study carried out and for how long?

To obtain reliable results, the first examination is prescribed between the eleventh and thirteenth weeks of pregnancy. Before or after this period, it is impossible to pass the test, otherwise there is a chance not to see the pathology.

It is possible to refuse planned examinations during pregnancy, but this will be considered negligent to your health. Such a decision carries a risk for the child. Refusing scheduled checks, a woman puts his life in danger.

The procedure consists of two stages:

1. Diagnostics by ultrasound;
2. Study of blood biochemistry.

There are rules for undergoing an ultrasound examination - an expectant mother an hour and a half before the examination is obliged to drink half a liter of ordinary, clean, non-carbonated water. The bladder during ultrasound should be full so that the specialist can better examine the position of the fetus and its condition. Instead of drinking water, you can not urinate three hours before the examination.

When a specialist uses a transvaginal fetal examination method, the sensor is inserted into the vagina, so the preparation described above is not required. However, it is advisable to go to the toilet before that.

After ultrasound, a blood biochemistry test is done. It is this order that is required, since blood counts can change very quickly, but if you undergo an ultrasound examination before that, then it will be possible to establish the condition of the baby without any problems.

A pregnant woman should go for blood donation with the results of an ultrasound, where the gestational age will be indicated. Unfortunately, sometimes ultrasound shows pregnancy regression or fading, then blood donation will no longer be needed. To prepare for blood sampling, you need to drink only clean water, exclude food and any drinks - blood sampling takes place on an empty stomach.

The specialist will conduct an ultrasound, the results of which will confirm or refute the presence of pathologies

What can be learned from screening?

Often, specialists cannot immediately consider all the data, so they ask the expectant mother to turn on the other side, walk around, cough, or even squat. Thus, the fetus changes position.

The specialist examines the following indicators:

1. Coccyx-parietal size, or CTE. It is carried out from the parietal point on the fetal head to the coccyx.
2. Biparietal size, or BDP - a study of the distance between the tubercles of the crown zone.
3. Measure the circumference of the head and the distance from the back of the head to the forehead.
4. They check the structure of the brain, whether the hemispheres are symmetrical, whether the cranium is closed.
5. Check the thickness of the collar zone, or TVP.
6. They study the frequency of contractions of the heart muscle, its size and the size of large vessels.
7. Check the length of the bones of the shoulders, thighs, lower leg and forearm.
8. The thickness of the placenta and its structure, as well as its location in the uterus.
9. The location of the umbilical cord and the number of vessels in it.
10. The amount of amniotic fluid.
11. Tone of the uterus.
12. Condition of the cervix.

If the study is carried out earlier than at the eleventh week, then not all organs and bones are still sufficiently formed so that the specialist can check them for abnormalities.

Starting biochemistry, it turns out to determine some important indicators, for example, chorionic gonadotropin β-hCG. This hormone is produced by the fetus. Interestingly, it is with its help that you can determine the presence of pregnancy.

3D ultrasound examination is now possible

If a girl is in position and does a test, then a special substance on the test strip reacts to the presence of a hormone. From the beginning of the first days of pregnancy (if it proceeds without complications), the amount of hormone produced gradually increases, reaching a peak by the twelfth week. Further, the level of the hormone begins to gradually fall. In the second half of the term, the indicators of β-hCG remain unchanged.

Below is the norm of β-hCG indicators by week:

• tenth - from 25.80 to 181.60 ng / ml;
• eleventh, from 17.4 to 130.3 ng/ml;
• twelfth - from 13.4 to 128.5 ng / ml;
• thirteenth - from 14.2 to 114.8 ng / ml.

If the indicators exceed the norm, then there are several options - Down syndrome in a child, the mother suffers from severe toxicosis, or she has diabetes.

If the readings are below normal, then this also indicates several problems: placental insufficiency, threatened miscarriage, ectopic pregnancy, or Edwards syndrome in a child. Another important indicator in the blood is protein-A. Protein is responsible for the proper development and functioning of the placenta.

Below is the norm of protein-A (PAPP-A) indicators by week:

• tenth - from 0.45 to 3.73 mU / ml;
• eleventh - 0.78 to 4.77 mU / ml;
• twelfth - from 1.03 to 6.02 mU / ml;
• thirteenth - from 1.47 to 8.55 honey / ml.

When the indicators are below normal, this may signal the presence of such abnormalities as Down syndrome, Edwards or Cornelia de Lange. But there are also cases when an elevated protein level does not signal the presence of the pathologies listed above.

Rules for preparing for the study

Always have an ultrasound first. There are two types of ultrasound examination - transabdominal and transvaginal. The first is carried out, as usual, by moving the sensor along the belly of the pregnant woman. During the second, the probe is inserted into the vagina.

In the first case, you must definitely go to the procedure with a full bladder - drink about one and a half liters of clean water without gas in half an hour. The second method does not involve any special preparatory measures. When the results of the ultrasound are issued, the woman must donate blood for analysis. It is taken from a vein, so be sure to take it on an empty stomach and do not drink drinks other than water.

To get the most reliable results, a pregnant woman must exclude sweet, smoked, fried and fatty foods from her menu three days before the analysis, as well as foods that cause allergies - citrus fruits, chocolate, nuts and seafood.

During a transabdominal examination, you need to drink one and a half liters of water or not go to the toilet for several hours

Screening for the first trimester of pregnancy

As already written above, it is carried out no earlier than the eleventh, but no later than the thirteenth week. It is during this period that the so-called embryonic period of fetal development ends, and the fetal period begins.

This means that from an embryo turns into a fetus, organs are already beginning to develop, like in a full-fledged person. During this period, pathologies or deviations can be detected.

Of course, only a specialist will correctly decipher the screening results, but expectant mothers can at least in general terms know what to expect and what some indicators can mean.

Who is referred for 1st trimester screening?

You can opt out of screening, but doctors advise against it

All pregnant women are referred, but this procedure can be waived. Doctors do not recommend refusing, as this is a negligent attitude to the life of the baby. The following groups of women should also be screened:

• over 35 years old;
• there were unsuccessful attempts to give birth - a fetus, a miscarriage;
• those who work in industries and may come into contact with harmful substances;
• who gave birth to a child with disabilities in the past;
• during the first weeks who had an infection;
• taking drugs prohibited for the first trimester;
• suffering from alcoholism or drug addiction;
• when there is a threat;
• if there are pathologies in the family.

How the study is done

There is a special medical worker, a sonologist, who performs the procedure. At this time, there are two options - abdominal and transvaginal examination. The second one is preferred because it is more reliable.

There are machines for home ultrasound

The woman is asked to undress to the waist and lie down on the couch with her legs bent. Then a thin probe in a condom is inserted into the vagina. They will be moved to fully examine the fetus, which may be uncomfortable but not painful. After the procedure, some discharge may appear on the linen, possibly a little bloody.

This is normal, no need to worry. Ultrasound of the abdomen does not give reliable results at this time, but if it is chosen, then the woman is asked to lift her clothes to open her stomach. Then you have to wait for the results - in public hospitals up to five days. After that, you need to donate blood for analysis.

1st trimester screening price

It is known that not even all state institutions are ready to provide such a service for free. The blood biochemistry alone exceeds one and a half thousand rubles, and you also have to pay for the ultrasound procedure itself. Each clinic sets the cost in its own way, but it is unlikely to be lower than two thousand rubles.

Deciphering the screening of the 1st trimester by ultrasound, norms and possible deviations

To accurately obtain reliable results, the following conditions are met:

• the process occurs only from 12 to 13 weeks;
• the fetus must be in the correct position - if something interferes, the doctor will ask you to move, then the baby will roll over;
• coccygeal-parietal size (hereinafter in the KTR article) is at least 45 mm.

Various indicators, such as the length of the nasal bone, can indicate an illness in a child.

PAPP-A - what is it?

This indicator in biochemical analysis is a protein that is produced by the placenta. If its indicator is exceeded or it is not enough in the body of a pregnant woman, then this may be a signal for the development of a pathology of a genetic nature.

Human chorionic gonadotropin (hCG)

A hormone produced by the chorion. Immediately after conception, in the very first hours, its level begins to rise. Until 11-12 weeks, the initial figure grows thousands of times.
Then the production of the hormone slows down - somewhere at the beginning of the second trimester, and then remains unchanged.

An increase in the rate may indicate:

• Down syndrome;
• multiple pregnancy;
• the development of diabetes in the mother;
• for toxicosis.

The deficiency indicates:

• Edwards syndrome in a baby;
• risk of miscarriage;
• placental insufficiency.

Remember, only a specialist can correctly determine the risk.

What is KTP during pregnancy on ultrasound

This is the coccyx-parietal size, which identifies the correct development of the baby inside the mother's womb. The size of the CTE is compared with the weight of the child and the gestational age. It is believed that the higher this indicator, the longer the gestational age.

KTR norms

When the KTR is above the norm, then the child at birth will weigh more than 3-3.5 kilograms.

But if the indicator is lower, then:

1. There is a risk that the pregnancy develops abnormally. Then you should check the baby's heartbeat to make sure that he did not die in the womb. If this happens, urgent hospitalization is necessary.
2. You may not be producing enough hormones, especially progesterone. In this case, the specialist sends for further examination and prescribes medication.
3. Mom can suffer from an infectious disease, even from a venereal disease.
4. There is a genetic defect.

In some cases, a low CTE signals an incorrectly set gestational age.

Fetal BDP (biparietal size)

Thus, the size of the fetal head is measured. It is this indicator that is considered the main one when determining the correctness of child development.

Also, this indicator determines whether the birth will be normal or you will have to do a caesarean section. If the head is too large, then the mother will not be able to give birth to him in the usual way, only through caesarean.

Collar space thickness (TVP)

This place is located between the neck and the upper skin membrane of the fetal body, there is an accumulation of fluid in it. This indicator begins to decrease from the 14th week, and by the 16th it is practically not visible. There are rules that indicate the presence or absence of deviations. To do this, measure the thickness of this space.

The timing of screening is determined by the timing of fetal development

Signs of Down syndrome, as well as Edwards and Patau

A sign of Down syndrome can be considered a decrease in the level of protein-A (PAPP-A), low or high hCG. These same signs can also signal Edwards syndrome, therefore, in the case of such results, the pregnant woman is sent for additional examinations.

Nasal bone at 12 weeks, table of norms

With a genetic deviation, it develops incorrectly, more precisely, it ossifies later than usual. If it is too small, or not at all, there may be an anomaly in development. There is a special table of norms.

Heart rate (HR)

In the first stages of life, it is normal when the baby's heart rate is equal to the mother's pulse rate - about 83 beats. But the higher the term, the higher the frequency of contractions. Every day, about three beats per minute will be added. Closer to the 9th week, the frequency is 175 beats per minute.

What can distort the result

False positive results occur in such cases:

1. Artificial insemination.
2. Excess weight increases the concentration of all hormones, lack - reduces.
3. With multiple pregnancy.
4. With diabetes.
5. Even stress and fear of the procedure can affect the result, so it is necessary to carry out the procedure in a calm state.

The doctor will explain to you all the indicators of the norm and tell you who to contact if something is wrong

What is risk and how is it calculated?

The risk of developing pathology is calculated for each woman individually, because many parameters influence this - age, bad habits, weight, etc. All data about the woman, as well as the results of screening, are entered into a computer program that calculates the risk.

What if I am at high risk?

If a child is at risk of developing Down syndrome, then there is no need to panic. You should consult a geneticist, he will consider the situation in more detail.

How to confirm or refute the results of screening?

You have the right to be screened again if you think previous results are incorrect. But you will have to undergo an examination in another clinic and only if the gestational age is not higher than 13 weeks.

The doctor says I need to have an abortion. What to do?

No one has the right to force you to terminate a pregnancy if you are at risk of developing Down syndrome. Tell your doctor that you want to see a geneticist. He will send you for one of the procedures - a chorionic villus biopsy (in case of pregnancy for a period of 10 to 13 weeks), or an amniocentesis (16-17 weeks).

Second screening during pregnancy, when to do and what is included in the study

As with the first screening, the second screening will also require an ultrasound and blood test. It occurs from 16 to 20 weeks of pregnancy.

Even with a poor screening result, you should not get upset ahead of time - you can go through the procedure again

Third screening during pregnancy

If the previous two screenings showed no deviations, then the pregnant woman will only have to undergo an ultrasound diagnosis, and she will not need to donate blood (but usually they insist on this).

In addition, it is necessary to go through such procedures.

Examination of the state of the growing embryo for the detection of chromosomal abnormalities, the prognosis of the development of pregnancy is carried out at the first screening during pregnancy. How it is done, what results are considered acceptable - is determined by the ultrasound doctor, geneticist, biochemist.

The correct calculation of the gestational age helps to determine not only the expected date of birth. It is necessary for planning the first screening. By the beginning of the 11th week, the embryonic period of development ends. Formed organs, limbs, facial bones appear, the nervous system is formed.

Screening of the first trimester of pregnancy is carried out by the end of the term. The allowable completion date of the study is 13 weeks and 6 days.

It is useless to screen before these dates: the picture of pathologies may be distorted and will not lead to the detection of pathologies.

Features of the first screening examination

The difference in the first screening examination is the use of a transvaginal method for introducing an ultrasound probe. This method is carried out by inserting a sensor into the vagina.

Transvaginal ultrasound is performed only in the 1st trimester of pregnancy. By the 16th week, the height of the uterus noticeably increases, the fetus becomes larger, which allows for examinations of the 2nd, 3rd screening to be limited only to the transabdominal method.

Preparation for the examination

The fatty layer, accumulated gases in the intestines, can interfere with a clear view of the fetus and uterus during a transabdominal examination. To eliminate the causes, it is necessary to prepare within 2 - 3 days.

It is necessary to refuse foods high in fiber, which can increase gas formation. The procedure must be carried out on a full bladder. To do this, before starting the study, it is recommended to drink 1 - 1.5 liters of water without gases.

Blood sampling for hCG hormones, PAPP-A is performed on an empty stomach, with a preliminary rejection of fried, fatty, sweet foods for 2 to 3 days. Dieting is not important, but it will allow you to more accurately reveal the picture of the hormonal background of the mother and fetus.

How the examination is carried out

The first screening during pregnancy, as done, is decided by the doctor based on the specified gestational age. Contact of the sensor with the body is facilitated by a special gel based on glycerin, which is applied to the skin. The uterus with the available amniotic fluid actively conducts sounds.

This allows you to study the development of the fetus, listen to its heartbeat, register pathologies of organs and systems. The awkward position of the fetus in the uterus can make a comprehensive examination difficult. In this case, the woman needs to provoke the child to change the position with light active movements.

The survey is carried out in 2 stages:

Ultrasound - research:

Test for hCG hormones, PAPP-A. If high risks of fetal pathology are detected, an additional examination of amniotic fluid and placental cells is prescribed.

Goals of the first screening

The purpose of 1st trimester screening is to:

• Determining the timing of pregnancy.
• Clarification of the compliance of the size of the fetus with developmental standards.
• Identification of pathologies of the bone, cardiovascular, system, gastrointestinal tract.
• Detection of genetic diseases - syndromes. Down, Edwards.
• Exclusion of other possible malformations.
• Monitoring of the placenta.
• Condition, readiness of the uterus for bearing.

According to the results of test studies, a conclusion is made about the condition of the fetus, a prognosis is given for the further development of pregnancy. Early detection of pathologies allows you to pay attention to possible risks, to prevent the further development of complications.

Severe complications that threaten the life of the mother and give reason to recommend artificial termination of pregnancy in the early stages.

Ultrasound norm indicators - research

Prenatal screening is considered harmless to mother and baby. Comparison of the obtained indicators with the standards gives the most complete picture of the condition and risks of pregnancy.

Basic indicators:

• KTR (coccygeal - parietal size). The length of the fetus from the crown to the coccyx should be from 43 to 85 mm. A decrease in the length of the fetus indicates a slow development, or genetic pathology.
• BDP (biparietal size). Determined by the distance from temple to temple. Changes in BDP data indicate pathologies of the brain.
• TVP (collar space thickness). An increased indicator requires an in-depth analysis for the detection of Down syndrome, Edwards.
• The length of the nose bone. Research indicators range from anatomical structural features to genetic pathologies.
• HR (heart rate). A noticeable decrease or increase in heart rate indicates possible violations of the brain, defects in internal organs.
• The size of the chorion, amnion and yolk sac. At the first stage of fetal development, they are the basis of the placenta, which is necessary for normal pregnancy. The wrong location of the chorion threatens miscarriage. Amnion indicators are necessary for the study of amniotic fluid. The yolk sac is a nutrient medium for the development of internal organs. Its absence or minimal presence indicates the dynamics of the development of pregnancy.

Collar thickness

The thickness of the collar space (NTP) is an important indicator of the risk of chromosomal diseases. Collar space - subcutaneous fluid that accumulates between the outer surface of the skin and bone tissue.

How to do the first screening during pregnancy in order to exclude incorrect results depends on the qualifications of the gynecologist. It is important not to be mistaken in determining the gestational age required for this study. Fetal size at 10 weeks is insufficient for testing. By 14 weeks, the size of the cervical fold is physiologically reduced.

There are conditions that must be observed to obtain the most correct result:

• Accurate determination of the gestational age. It is determined by the size of the coccyx-parietal zone.
• The lateral position of the embryo allows you to most clearly determine the data of the test. The inability to achieve the correct position of the fetus gives reason to use the transvaginal method of research.
• Physician competence. Loops of the umbilical cord, amniotic cavities can give positive results. An experienced doctor using high-precision equipment should exclude false positive results.

A complete picture of the state of the embryo is given not only by ultrasound data - studies, but also by the analysis of biochemical markers. Test results may vary at different stages of pregnancy. The general boundaries of the examination of the fluid of the collar fold should vary from 0.7 mm to 4 mm.

An increase in TVP data gives grounds for an in-depth examination, which includes the study of amniotic fluid, placenta, cord blood.

nasal bone

A short nasal bone does not always mean a pathological condition of the embryo. A noticeable decrease in its length, combined with positive results of TVP, give grounds to define pregnancy as pathological. A serious developmental disorder is nasal aplasia - its complete absence.

At the lower limits of the screening period, only the presence or absence of the nasal bone is detected. 12 - 13 weeks of pregnancy allows you to specify the size of the nose bone in numerical values. Permissible limits are from 2 to 4.2 mm. Small deviations may indicate the anatomical features of the unborn child.

A significant decrease in the indicator indirectly indicates chromosomal abnormalities. However, these data are not enough for a definitive diagnosis. The conclusion about the presence of severe genetic defects is possible only with additional deep monitoring of the fetus and mother.

Heart rate

The heart rate of a healthy fetus should match developmental parameters. The indicator is correct, subject to compliance with the KTR data. The size from the coccyx to the crown must be at least 8 mm. Only in this case can we talk about the recommended heart rate indicators. As the fetus grows, they decrease.

If at 9-10 weeks the heartbeat is 170-190 beats per minute, then by the 13th week it drops to 160 beats. Small deviations are physiological errors and do not pose a danger. The absence of a heartbeat indicates a missed pregnancy. Repeated ultrasound, additional studies will be able to confirm or refute the presumptive diagnosis.

A decrease in heart rate of less than 100 beats per minute may indicate Edwards syndrome.

An increase in heart rate up to 200 beats per minute is a dangerous symptom of Patau's syndrome. Heart rate markers are not decisive for the diagnosis of chromosomal diseases. They indicate the risks of developing pathologies. Comprehensive monitoring of all organs and systems is designed to give a complete prognosis of pregnancy.

Biparental size

Biparental size means digital measurements of the width of the fetal head from temple to temple. BDP is the main indicator of the development of the brain of an unborn child.

The indicators can also serve as the basis for specifying the gestational age and, in some cases, determining the method of physiological childbirth. With a large size of the baby's head, the question of a planned caesarean section may arise.

The rate of BDP at 11 - 13 weeks of development should be in the range from 13 to 28 mm. Going beyond the limits of the norm is allowed, subject to a proportional increase in all indicators - KTR, TVP, nasal bone. This indicates the large size of the fetus. Slightly elevated BDP, while the rest of the markers correspond to the norm, levels off by the end of 14 weeks.

A noticeable increase in the indicator indicates the presence of brain pathologies that are incompatible with life.

The minimum dimensions of the BDP indicate underdevelopment of the hemispheres or the absence of brain segments. Severe malformations are not amenable to treatment, the perinatal prognosis is unfavorable. The choice of terminating or leaving a pregnancy is made by the woman herself.

Norms of hormones that are determined by the first screening (hCG, PAPP-A)

The biochemical stage of prenatal screening is to study the levels of hCG hormones, PAPP-A. Blood markers for determining the level of hormones are a necessary element in the study of fetal development.

Chorionic gonadotropin is responsible for the normal course of pregnancy and consists of two units - α and β. The hormone is responsible for stimulating the production of hormones, the gonads. Its amount increases by 9-10 weeks, and then, the concentration decreases. The norm corresponds to 17 - 114 mIU / ml.

An increase in hCG indicates the risk of detecting genetic pathologies - Down syndrome. A downward change puts pregnancy at risk for detecting Edwards syndrome, developmental delay, and fetal death.

The purpose of determining the level of the PAPP-A hormone is to identify chromosomal pathologies - Down syndrome, Edwards, Cornelia de Lange, the risk of miscarriage. The normative indicator varies from 0.45 to 6.0 mU / ml. A significant decrease in the value in numerical terms indicates the need for additional research, the appointment of an in-depth triple test.

What pathologies can be detected by the first screening? (Down syndrome, Edwards syndrome, Patau syndrome)

The first screening makes it possible to monitor the condition of the fetus, identify future pathologies of physical and mental development. Comparison of indicators of biparental sizes, distance of the coccygeal-parietal zone, nasal bone, hormonal state give the most accurate predictions of fetal development and current pregnancy.

Genetic disorders are associated with chromosomal abnormalities - trisomy. It is characterized by the presence of a triple pair of chromosomes instead of two.

Risk calculation at first screening

The totality of the data of the first screening gives the most complete picture of the course of pregnancy. Predictions, decisions to prolong pregnancy is a serious issue. You should carefully consider the examination process and test results.

Numerical values ​​of biochemical analysis may differ depending on the research methods of laboratories. It is recommended to conduct screenings in one medical center, for the reliability of observation in a single measurement scale. It is important to consider how the first screening is done during pregnancy, what factors are taken into account when calculating the data.

The presence of pathologies may be the result of:

Survey data are expressed as proportions of risk in relation to the total number of similar results. For example, a fraction of 1:10,000 means: for 10,000 pregnancies with similar indicators, there is 1 risk of confirming the diagnosis.

A fraction with a smaller denominator is considered an unfavorable forecast. The probability of detecting an anomaly is higher in a pregnant woman with rates of 1:300 than 1:627.

The first pregnancy screening is done to influence the final medical opinion. A positive test result means a high risk of fetal pathology. To confirm or exclude it, it is necessary to undergo an additional study of the placental membrane, amniotic fluid, cord blood.

Can indicators be false?

There are factors that distort the results of the survey.

Anatomical features of the structure of a woman, subjective conditions of the body lead to false positive results:

The birth of a healthy child, despite the positive data of the examination, indicates the relative imperfection of the study, the influence of subjective factors on the examination process.

The first screening in pregnancy is thought to be affected by false negative results. It is a consequence of a defect in the examination methodology, low-quality reagents. The birth of a child with developmental anomalies with negative screening results refers to the percentage of statistical error, but it is a tragedy and a serious test for the family.

It is necessary to remember why and how the first screening for pregnant women is carried out. The procedure is planned, painless, affordable. Identification of the risk of detecting a genetic pathology is a reason for further in-depth examination. The decision to terminate the pregnancy or continue it, the woman takes on her own.

Video of the first screening

Pregnancy management. First screening:

11-13 weeks of pregnancy. Diary of a pregnant woman:

Some time ago, pregnant women did not even know about such a procedure as prenatal or perinatal . Now all expectant mothers undergo such a survey.

What is pregnancy screening, why is it done, and why are results so important? Answers to these and other questions of concern to many pregnant women about perinatal screening we have tried to give in this material.

In order to exclude any further misunderstanding of the information presented, before proceeding directly to the consideration of the above topics, it is worth defining some medical terms.

Prenatal screening is a special kind of such actually standard procedure as screening. Given comprehensive examination consists of ultrasound diagnostics and laboratory research, in this particular case maternal serum biochemistry. Early detection of some genetic abnormalities - this is the main task of such an analysis during pregnancy as screening.

prenatal or perinatal means prenatal, and under the term screening in medicine, it means a series of studies of a large stratum of the population, which are carried out in order to form the so-called "risk group", prone to certain diseases.

Can be universal or selective screening .

It means that screening studies are done not only for pregnant women, but also for other categories of people, for example, children of the same age, to establish diseases characteristic of a given period of life.

With help genetic screening doctors can learn not only about problems in the development of the baby, but also respond in time to complications during which a woman may not even suspect.

Often, expectant mothers, having heard that they will have to undergo this procedure several times, begin to panic and worry in advance. However, there is nothing to be afraid of, you just need to ask the gynecologist in advance why you need screening for pregnant women, when and, most importantly, how this procedure is done.

So, let's start with what is standard screening carried out three times during the entire pregnancy, i.e. in every trimester . Recall that trimester is a period of three months.

What it is 1st trimester screening ? First, let's answer the common question about how many weeks it is. first trimester of pregnancy . In gynecology, there are only two ways to reliably determine the period during pregnancy - calendar and obstetric.

The first is based on the day of conception, and the second depends on menstrual cycle , preceding fertilization . That's why I trimester - this is the period that, according to the calendar method, begins with the first week from conception and ends with the fourteenth week.

According to the second method, I trimester - This is 12 obstetric weeks. Moreover, in this case, the period is counted from the beginning of the last menstruation. Recently screening not prescribed to pregnant women.

However, now many expectant mothers themselves are interested in undergoing such an examination.

In addition, the Ministry of Health strongly recommends that examinations be ordered for all expectant mothers without exception.

True, this is done voluntarily, because. no one can force a woman to undergo any kind of analysis.

It is worth noting that there are categories of women who are simply obliged, for one reason or another, to go through screening, For example:

• pregnant women from thirty-five years and beyond;
• expectant mothers with a history of a threat spontaneous ;
• women who in the first trimester suffered infectious diseases ;
• pregnant women who, for health reasons, are forced to take medicines prohibited for their position in the early stages;
• women who had various previous pregnancies genetic abnormalities or anomalies in the development of the fetus ;
• women who have already given birth to children with any deviations or malformations in development ;
• women who have been diagnosed frozen or regressive pregnancy (cessation of fetal development);
• suffering from narcotic or women;
• pregnant women in whose family or in the family of the father of the unborn child cases of hereditary genetic abnormalities .

At what time do prenatal screening 1st trimester ? For the first screening during pregnancy, the period is set in the interval starting from 11 weeks to 13 obstetric weeks of pregnancy and 6 days. Earlier than the indicated period, it makes no sense to conduct this survey, since its results will be uninformative and absolutely useless.

The first ultrasound at the 12th week of pregnancy is done by a woman for a reason. Since this is the end of embryonic and starts fetal or fetal period of human development.

This means that the embryo turns into a fetus, i.e. there are obvious changes that speak of the development of a full-fledged living human body. As we said before, screening studies - This is a set of measures that consists of ultrasound diagnostics and biochemistry of a woman's blood.

It is important to understand that the screening ultrasound in the 1st trimester during pregnancy plays the same important role as laboratory blood tests. After all, in order for geneticists to make the right conclusions based on the results of the examination, they need to study both the results of ultrasound and the biochemistry of the patient's blood.

We talked about how many weeks the first screening is carried out, now let's move on to deciphering the results of a comprehensive study. It is really important to consider in more detail the norms established by doctors for the results of the first screening during pregnancy. Of course, only a specialist in this field who has the necessary knowledge and, most importantly, experience can give a qualified assessment of the results of the analysis.

We believe that it is advisable for any pregnant woman to know at least general information about the main indicators prenatal screening and their standard values. After all, it is common for most expectant mothers to be overly suspicious about everything related to the health of their unborn child. Therefore, they will be much more comfortable if they know in advance what to expect from the study.

Deciphering the screening of the 1st trimester by ultrasound, norms and possible deviations

All women know that during pregnancy they will have to undergo more than once an ultrasound examination (hereinafter referred to as ultrasound), which helps the doctor track the intrauterine development of the unborn child. In order to screening ultrasound gave reliable results, you need to prepare in advance for this procedure.

We are sure that the vast majority of pregnant women know how to do this procedure. However, it is not superfluous to repeat that there are two types of research - transvaginal and transabdominal . In the first case, the sensor of the device is inserted directly into the vagina, and in the second case it is in contact with the surface of the anterior abdominal wall.

There are no special preparation rules for the transvaginal type of ultrasound.

If you are going to undergo a transabdominal examination, then before the procedure (approximately 4 hours before the ultrasound), you should not go to the toilet “little by little”, and it is recommended to drink up to 600 ml of plain water in half an hour.

The thing is that the examination must be carried out necessarily on a liquid-filled bladder .

In order for the doctor to get a reliable result ultrasound screening, the following conditions must be met:

• the period of the examination is from 11 to 13 obstetric weeks;
• the position of the fetus should allow the specialist to carry out the necessary manipulations, otherwise mommy will have to “influence” the baby so that he rolls over;
• coccygeal-parietal size (hereinafter KTR) should not be less than 45 mm.

What is KTP during pregnancy on ultrasound

When conducting an ultrasound, a specialist without fail examines various parameters or sizes of the fetus. This information allows you to determine how well the baby is formed and whether it is developing correctly. The norms of these indicators depend on the gestational age.

If the value of one or another parameter obtained as a result of ultrasound deviates from the norm up or down, then this is considered a signal of the presence of some pathologies. Coccyx-parietal size - This is one of the most important initial indicators of the correct intrauterine development of the fetus.

The KTP value is compared with the fetal weight and gestational age. This indicator is determined by measuring the distance from the bone of the crown of the child to his tailbone. As a general rule, the higher the KTR, the longer the gestational age.

When this indicator slightly exceeds or, on the contrary, slightly less than the norm, then there is no reason to panic. It speaks only about the peculiarities of the development of this particular child.

If the CTE value deviates from the standards upwards, then this indicates the development of a large-sized fetus, i.e. presumably, the weight of the child at birth will exceed the average norms of 3-3.5 kg. In cases where the CTE is significantly less than the standard values, this may be a sign that:

• pregnancy does not develop as it should, in such cases, the doctor should carefully check the fetal heartbeat. If he died in the womb, then the woman needs urgent medical care ( curettage of the uterine cavity ) to prevent a possible health hazard ( development of infertility ) and life ( infection, bleeding );
• the body of a pregnant woman produces an insufficient amount, as a rule, which can lead to spontaneous miscarriage. In such cases, the doctor prescribes an additional examination to the patient and prescribes medications containing hormones ( , Dufston );
• mother is sick infectious diseases , including venereal;
• the fetus has genetic abnormalities. In such situations, doctors prescribe additional studies along with, which is part of the first screening analysis.

It is also worth emphasizing that there are often cases when a low CTE indicates an incorrectly established gestational age. This refers to the variant of the norm. All a woman needs in such a situation is to undergo a second ultrasound examination after a while (usually after 7-10 days).

Fetal BDP (biparietal size)

What is BDP on ultrasound during pregnancy? When conducting an ultrasound examination of the fetus in the first trimester, doctors are interested in all possible characteristics of the unborn child. Since their study gives specialists maximum information about how the intrauterine development of a little man takes place and whether everything is in order with his health.

What is it fetal BD ? First, let's decipher the medical abbreviation. BDP - This biparietal size of the fetal head , i.e. distance between walls parietal bones of the skull , in a simple way, the size of the head. This indicator is considered one of the main indicators for determining the normal development of the child.

It is important to note that BDP shows not only how well and correctly the baby is developing, but also helps doctors prepare for the upcoming delivery. Since if the size of the head of the unborn child deviates from the norm upwards, then he simply will not be able to pass through the mother's birth canal. In such cases, a planned caesarean section is prescribed.

When BDP deviates from established norms, this may indicate:

• about the presence in the fetus of pathologies incompatible with life, such as cerebral herniation or tumor ;
• about a sufficiently large size of the unborn child, if other basic parameters of the fetus are several weeks ahead of the established development standards;
• about spasmodic development, which after some time will return to normal, provided that other basic parameters of the fetus fit into the norm;
• on fetal development brain arising from the presence of infectious diseases in the mother.

The deviation of this indicator downward indicates that the baby's brain is developing incorrectly.

Collar space thickness (TVP)

Fetal TVP - what it is? Collar space fetus or size neck fold - this is a place (more precisely, an oblong formation) located between the neck and the upper skin membrane of the baby's body, in which there is an accumulation of fluid. A study of this value is carried out during screening of the first trimester of pregnancy, since it is at this time that it is possible to measure TVP for the first time, and then analyze it.

Starting from the 14th week of pregnancy, this formation gradually decreases in size and by the 16th week it practically disappears from visibility. For TVP, certain norms are also established, which are directly dependent on the gestational age.

For example, the norm collar space thickness at 12 weeks should not go beyond the range of 0.8 to 2.2 mm. Collar space thickness at 13 weeks should be in the range from 0.7 to 2.5 mm.

It is important to note that for this indicator, experts set the average minimum values, the deviation from which indicates a thinning of the collar space, which, like the expansion of the TVP, is considered an anomaly.

If this indicator does not correspond to the TVP norms indicated in the above table at 12 weeks and at other stages of pregnancy, then this result most likely indicates the presence of the following chromosomal abnormalities:

• trisomy 13 , a disease known as patau syndrome, characterized by the presence in human cells of an additional 13th chromosome;
• trisomy on chromosome 21, known to all as down syndrome , a human genetic disease in which karyotype (i.e., the complete set of chromosomes) is represented by the 47th chromosome instead of 46;
• monosomy on the X chromosome , a genomic disease named after the scientists who discovered it Shereshevsky-Turner syndrome, it is characterized by such anomalies of physical development as short stature, as well as sexual infantilism (immaturity);
• trisomy 18 is a chromosomal disorder. For Edwards syndrome (the second name of this disease) is characterized by a plurality of malformations that are incompatible with life.

Trisomy is an option aneuploidy , i.e. changes karyotype , in which the human cell has an additional third chromosome instead of normal diploid set.

Monosomy is an option aneuploidy (chromosomal abnormality) in which there are no chromosomes in the chromosome set.

What are the standards for trisomy 13, 18, 21 established during pregnancy? It happens that in the process of cell division a failure occurs. This phenomenon is scientifically called aneuploidy. Trisomy - this is one of the varieties of aneuploidy, in which instead of a pair of chromosomes, an extra third chromosome is present in the cell.

In other words, the child inherits from his parents an additional 13, 18 or 21 chromosome, which in turn entails genetic abnormalities that prevent normal physical and mental development. Down syndrome according to statistics, this is the most common disease due to the presence of chromosome 21.

Children born with Edwards syndrome, the same as in the case of patau syndrome , usually do not live up to a year, unlike those who are not lucky enough to be born with down syndrome . Such people can live to a ripe old age. However, such a life can rather be called existence, especially in the countries of the post-Soviet space, where these people are considered outcasts and they try to avoid and not notice them.

In order to exclude such anomalies, pregnant women, especially those at risk, must undergo a mandatory screening examination. Researchers argue that the development of genetic abnormalities is directly dependent on the age of the expectant mother. The younger the woman, the less likely it is that her child will have any abnormalities.

To establish trisomy in the first trimester of pregnancy, a study is being collar space of the fetus with the help of ultrasound. In the future, pregnant women periodically take a blood test, in which for geneticists the most important indicators are the level alpha-fetoprotein (AFP), inhibin-A, human chorionic gonadotropin (hCG), and estriol .

As mentioned earlier, the risk of having a genetic abnormality in a child depends primarily on the age of the mother. However, there are cases when trisomy is fixed in young women. Therefore, when screening, doctors study all possible signs of anomalies. It is believed that an experienced ultrasound specialist can identify problems during the first screening examination.

Signs of Down syndrome, as well as Edwards and Patau

Trisomy 13 is characterized by a sharp decrease in the level PAPP-A (PAPP associated with pregnancy protein (protein) A-plasma ). Also a marker of this genetic abnormality is. The same parameters play an important role in determining whether the fetus has Edwards syndrome .

When there is no risk of trisomy 18, normal values PAPP-A and b-hCG (free beta subunit of hCG) recorded in a biochemical blood test. If these values ​​deviate from the standards established for each specific period of pregnancy, then most likely the child will have genetic malformations.

It is important to note that in the case when, during the first screening, the specialist fixes signs indicating the risk trisomy , the woman is referred for further examination and for a consultation with geneticists. To make a final diagnosis, the expectant mother will have to undergo procedures such as:

• chorion biopsy , i.e. obtaining a sample of chorion tissue for the diagnosis of anomalies;
• amniocentesis- This puncture of the amniotic membrane to get a sample amniotic fluid for the purpose of their further study in the laboratory;
• placentocentesis (biopsy of the placenta) , given invasive diagnostic method specialists take a sample placental tissue using a special puncture needle, which pierces anterior abdominal wall ;
• cordocentesis , a method for diagnosing genetic abnormalities during pregnancy, in which the umbilical cord blood of the fetus is analyzed.

Unfortunately, if a pregnant woman has undergone any of the above studies and is bioscreening and ultrasound the diagnosis of the presence of genetic abnormalities in the fetus has been confirmed, the doctors will offer to terminate the pregnancy. In addition, unlike standard screening studies, data invasive examination methods can provoke a number of serious complications up to spontaneous miscarriage, so doctors resort to them in a fairly rare number of cases.

nasal bone - This is a slightly elongated, quadrangular, convex front paired bone of the human face. At the first ultrasound screening, the specialist determines the length of the baby's nose bone. It is believed that in the presence of genetic abnormalities, this bone develops incorrectly, i.e. its ossification occurs later.

Therefore, if the nasal bone is missing or too small at the first screening, this indicates the possible presence of various anomalies. It is important to emphasize that the length of the nose bone is measured at 13 weeks or at 12 weeks. When screening at 11 weeks, the specialist checks only for its presence.

It is worth emphasizing that if the size of the nasal bone does not correspond to the established norms, but if other basic indicators are consistent, there is really no reason for concern. This state of affairs may be due to the individual characteristics of the development of this particular child.

Heart rate (HR)

A setting such as heart rate plays an important role not only in the early stages, but throughout pregnancy. Constantly measure and monitor fetal heart rate it is necessary only in order to notice deviations in time and, if necessary, save the life of the baby.

Interestingly, although myocardium (heart muscle) begins to decline as early as the third week after conception, you can hear the heartbeat only from the sixth obstetric week. It is believed that at the initial stage of fetal development, the rhythm of its heartbeats should correspond to the mother's pulse (on average, it is 83 beats per minute).

However, already in the first month of intrauterine life, the number of heartbeats of the baby will gradually increase (by about 3 beats per minute every day) and by the ninth week of pregnancy it will reach 175 beats per minute. Determine the fetal heart rate using ultrasound.

During the first ultrasound, specialists pay attention not only to the heart rate, but also to see how the baby's heart develops. To do this, use the so-called four-chamber cut , i.e. method of instrumental diagnosis of malformations of the heart.

It is important to emphasize that the deviation from the standards of such an indicator as heart rate indicates the presence malformations in the development of the heart . Therefore, doctors carefully study the structure on the cut atrial And fetal cardiac ventricles . If any abnormalities are found, the specialists refer the pregnant woman for additional studies, for example, echocardiography (ECG) with dopplerography.

Starting from the twentieth week, the gynecologist of the antenatal clinic will listen to the baby's heart with the power of a special tube at each scheduled visit to the pregnant woman. Such a procedure as auscultation of the heart not applied at earlier dates due to its inefficiency, tk. The doctor just can't hear the heartbeat.

However, as the baby develops, his heart will be heard more and more clearly each time. Auscultation helps the gynecologist determine the position of the fetus in the womb. For example, if the heart is better heard at the level of the mother's navel, then the child is in a transverse position, if the navel is to the left or lower, then the fetus is in cephalic presentation , and if above the navel, then in pelvic .

From the 32nd week of pregnancy, to control the heartbeat, use cardiotocography (abbreviated KTR ). When conducting the above types of examinations, a specialist can record in the fetus:

• bradycardia , i.e. abnormally low heart rate which is usually temporary. This deviation may be a symptom of the mother's autoimmune diseases, anemia, , as well as clamping the umbilical cord, when the unborn child does not receive enough oxygen. The cause of bradycardia can be congenital heart defects in order to exclude or confirm this diagnosis, a woman is necessarily sent for additional examinations;
• , i.e. high heart rate. Such a deviation is rarely recorded by specialists. However, if the heart rate is much higher than prescribed by the norms, then this indicates the mother or hypoxia , development intrauterine infections, anemia and genetic abnormalities at the fetus. In addition, medications a woman takes can affect heart rate.

In addition to the characteristics discussed above, when conducting the first screening ultrasound, specialists also analyze the data:

• about symmetry cerebral hemispheres fetus;
• about the size of the circumference of his head;
• about the distance from the occipital to the frontal bone;
• about the length of the bones of the shoulders, hips and forearms;
• about the structure of the heart;
• about the location and thickness of the chorion (placenta or "baby place");
• about the amount of water (amniotic fluid);
• about the state of the pharynx cervix mothers;
• about the number of vessels in the umbilical cord;
• about the absence or presence uterine hypertonicity .

As a result of ultrasound, in addition to the genetic abnormalities already discussed above ( monosomy or Shereshevsky-Turner syndrome, trisomy on chromosomes 13, 18 and 21 , namely Down, Patau and Edwards syndromes ) the following pathologies in development can be detected:

• neural tube , For example, spinal malformation (meningomyelocele and meningocele) or craniocerebral hernia (encephalocele) ;
• Cornet de Lange syndrome , an anomaly in which multiple malformations are fixed, entailing both physical abnormalities and mental retardation;
• triploidy , a genetic malformation in which a failure occurs in the chromosome set, as a rule, the fetus does not survive in the presence of such a pathology;
• omphalocele , embryonic or umbilical hernia, pathology of the anterior abdominal wall, in which some organs (liver, intestines, and others) develop in a hernial sac outside the abdominal cavity;
• Smith-Opitz syndrome , a genetic deviation that affects the processes, which subsequently leads to the development of many severe pathologies, for example, or mental retardation.

Biochemical screening of the 1st trimester

Let's talk in more detail about the second stage of a comprehensive screening examination of pregnant women. What it is biochemical screening of the 1st trimester, And what are the standards set for its main indicators? In fact, biochemical screening - is nothing but biochemical analysis blood of the expectant mother.

This study is carried out only after ultrasound. This is due to the fact that, thanks to an ultrasound examination, the doctor determines the exact gestational age, on which the standard values ​​​​of the main indicators of blood biochemistry directly depend. So, remember that you need to go for biochemical screening only with the results of an ultrasound scan.

How to prepare for your first pregnancy screening

We talked about how they do it, and most importantly, when they do a screening ultrasound, now you should pay attention to preparing for the biochemical analysis. As in the case of any other blood test, this study must be prepared in advance.

If you want to get a reliable result of biochemical screening, you will have to follow the following recommendations exactly:

• blood for biochemical screening is taken strictly on an empty stomach, doctors do not even recommend drinking plain water, not to mention any food;
• a few days before the screening, you should change your usual diet and begin to follow a sparing diet, in which you can not eat too fatty and spicy foods (so as not to increase the level), as well as seafood, nuts, chocolate, citrus fruits and other allergenic foods, even if you have not previously had an allergic reaction to anything.

Strict adherence to these recommendations will provide a reliable result of biochemical screening. Believe me, it’s better to be patient for a while and give up your favorite treats so that you don’t worry about the results of the analysis later. After all, any deviation from the established norms, doctors will interpret as a pathology in the development of the baby.

Quite often, in various forums dedicated to pregnancy and childbirth, women talk about how the results of the first screening, expected with such excitement, turned out to be bad, and they were forced to do all the procedures again. Fortunately, in the end, pregnant women received good news about the health of their babies, since the adjusted results showed the absence of any developmental abnormalities.

The whole point was that expectant mothers were not properly prepared for screening, which ultimately led to inaccurate data.

Imagine how many nerves were spent and bitter tears were shed while women were waiting for new test results.

Such colossal stress does not pass without a trace for the health of any person, and even more so for a pregnant woman.

Biochemical screening of the 1st trimester, interpretation of the results

When conducting the first biochemical screening analysis, indicators such as free β-subunit of human chorionic gonadotropin (Further hCG ), and PAPP-A (plasma protein A associated with pregnancy) . Let's consider each of them in detail.

PAPP-A - what is it?

As mentioned above, PAPP-A - This is an indicator of a biochemical blood test of a pregnant woman, which helps specialists to establish at an early stage the presence of genetic pathologies in the development of the fetus. The full name of this quantity sounds like pregnancy-associated plasma protein A , which in literal translation into Russian means - pregnancy-associated plasma protein A .

It is protein (protein) A, produced during pregnancy by the placenta, that is responsible for the harmonious development of the unborn child. Therefore, an indicator such as the level of PAPP-A, calculated at 12 or 13 weeks during pregnancy, is considered a characteristic marker for determining genetic abnormalities.

It is mandatory to undergo an analysis to check the level of PAPP-A should:

• pregnant women over the age of 35;
• women who have previously given birth to children with genetic abnormalities;
• expectant mothers in whose family there are relatives with genetic abnormalities in development;
• women who have had diseases such as , or shortly before pregnancy;
• pregnant women who have had complications or spontaneous miscarriages in the past.

Normative values ​​of such an indicator as PAPP-A depend on the gestational age. For example, the PAPP-A rate at 12 weeks is 0.79 to 4.76 mU/mL, and at 13 weeks is 1.03 to 6.01 mU/mL. In cases where, as a result of the test, this indicator deviates from the norm, the doctor prescribes additional studies.

If the analysis revealed a low level of PAPP-A, then this may indicate the presence chromosomal abnormalities in child development, for example, down syndrome, Also it signals the risk of spontaneous miscarriage and regressive pregnancy . When this indicator is increased, this is most likely the result of the fact that the doctor could not calculate the correct gestational age.

That is why blood biochemistry is taken only after an ultrasound scan. However, high PAPP-A may also indicate the likelihood of developing genetic abnormalities in the development of the fetus. Therefore, in case of any deviation from the norm, the doctor will refer the woman for an additional examination.

Scientists gave this name to this hormone not by chance, because it is thanks to him that you can reliably find out about pregnancy already 6-8 days after fertilization has occurred. eggs. It is noteworthy that hCG starts to develop chorion already in the first hours of pregnancy.

Moreover, its level is growing rapidly and by the 11-12th week of pregnancy it exceeds the initial values ​​​​by thousands of times. Then gradually loses its position, and its indicators remain unchanged (starting from the second trimester) until childbirth. All pregnancy test strips contain hCG.

If the level human chorionic gonadotropin increased, this may indicate:

• about the presence of the fetus down syndrome ;
• O multiple pregnancy ;
• about the development of the mother;

When the level of hCG is below the stipulated standards, it says:

• about a possible Edwards syndrome in the fetus;
• about risk miscarriage ;
• O placental insufficiency .

After the pregnant woman has undergone ultrasound and blood biochemistry, the specialist must decipher the results of the examination, as well as calculate the possible risks of developing genetic abnormalities or other pathologies using a special computer program PRISCA (Priska).

The screening summary form will contain the following information:

• about age risk anomalies in development (depending on the age of the pregnant woman, possible deviations change);
• about the values ​​of biochemical parameters of a woman's blood test;
• about the risk of possible diseases;
• MoM coefficient .

In order to calculate as reliably as possible the possible risks of developing certain abnormalities in the fetus, experts calculate the so-called MoM (multiple of median) coefficient. To do this, all the obtained screening data is entered into a program that builds a graph of the deviation of each indicator of the analysis of a particular woman from the average norm established for most pregnant women.

MoM is considered normal if it does not go beyond the range of values ​​​​from 0.5 to 2.5. At the second stage, this coefficient is adjusted taking into account age, race, presence of diseases (for example, diabetes ), bad habits (for example, smoking), the number of previous pregnancies, ECO and other important factors.

At the final stage, the specialist makes a final conclusion. Remember, only a doctor can correctly interpret screening results. In the video below, the doctor explains all the key points related to the first screening.

1st trimester screening price

The question of how much this study costs and where it is better to take it is of concern to many women. The thing is that not every state clinic can do such a specific examination for free. Based on the reviews left on the forums, many expectant mothers do not trust free medicine at all.

Therefore, you can often meet the question of where to do screening in Moscow or other cities. If we talk about private institutions, then in a fairly well-known and well-established INVITRO laboratory, biochemical screening can be done for 1600 rubles.

True, this cost does not include ultrasound, which the specialist will definitely ask to present before conducting a biochemical analysis. Therefore, you will have to separately undergo an ultrasound examination in another place, and then go to the laboratory for blood donation. And it must be done on the same day.

Second screening during pregnancy, when to do and what is included in the study

According to the recommendations of the World Health Organization (hereinafter referred to as WHO), every woman is required to undergo three screenings throughout the entire period of pregnancy. Although in our time, gynecologists refer all pregnant women to this examination, there are those who, for whatever reason, skip screening.

However, for some categories of women, such a study should be mandatory. This applies primarily to those who have previously given birth to children with genetic abnormalities or malformations. In addition, it is mandatory to undergo screening:

• women over the age of 35, since the risk of developing various pathologies in the fetus depends on the age of the mother;
• women who in the first trimester took drugs or other illegal drugs for pregnant women;
• women who have previously suffered two or more miscarriages;
• women who suffer from one of the following diseases that are inherited to the child - diabetes mellitus, diseases of the musculoskeletal system and the cardiovascular system, and oncopathology;
• women who are at risk of spontaneous miscarriage.

In addition, expectant mothers should definitely undergo screening if they or their spouses were exposed to radiation before conception, and also suffered immediately before or during pregnancy. bacterial and infectious diseases . As with the first screening, the second time, the expectant mother must also do an ultrasound and pass a biochemical blood test, which is often called a triple test.

Timing of the second screening during pregnancy

So, let's answer the question of how many weeks do the second screening during pregnancy. As we have already determined, the first study is carried out in the early stages of pregnancy, namely in the period from 11 to 13 weeks of the first trimester. The next screening test is carried out during the so-called "golden" period of pregnancy, i.e. in the second trimester, which starts at 14 weeks and ends at 27 weeks.

The second trimester is called golden because it is during this period of time that all the initial ailments associated with pregnancy ( nausea, weakness, and others) recede, and a woman can fully enjoy her new state, because she feels a powerful surge of strength.

A woman should visit her gynecologist every two weeks so that he can monitor the progress of the pregnancy.

The doctor gives the expectant mother recommendations regarding her interesting situation, and also informs the woman about what examinations and for how long she should undergo. As a standard, a pregnant woman takes a urine test and a complete blood count before each visit to the gynecologist, and the second screening takes place from 16 to 20 weeks of pregnancy.

Ultrasound screening 2nd trimester - what is it?

During the second screening first, an ultrasound scan is performed to determine the exact gestational age, so that later specialists can correctly interpret the results of a biochemical blood test. On ultrasound the doctor studies the development and size of the internal organs of the fetus: the length of the bones, the volume of the chest, head and abdomen, the development of the cerebellum, lungs, brain, spine, heart, bladder, intestines, stomach, eyes, nose, as well as the symmetry of the structure of the face.

In general, everything that is visualized with the help of an ultrasound examination is subjected to analysis. In addition to studying the main characteristics of the development of the baby, experts check:

• how the placenta is located;
• the thickness of the placenta and the degree of its maturity;
• the number of vessels in the umbilical cord;
• condition of the walls, appendages and cervix;
• quantity and quality of amniotic fluid.

Norms for ultrasound screening of the 2nd trimester of pregnancy:

Deciphering the triple test (biochemical blood test)

In the second trimester, experts pay special attention to three markers of genetic abnormalities, such as:

• chorionic gonadotropin - this is produced by the fetal chorion;
• alpha-fetoprotein ( Further AFP ) - This plasma protein (protein), initially produced yellow body, and then produced fetal liver and gastrointestinal tract ;
• free estriol ( further hormone E3 ) is a hormone produced in placenta , and fetal liver.

In some cases, they also study the level inhibin (hormone) produced follicles) . For each week of pregnancy, certain standards are established. It is considered optimal to conduct a triple test at 17 weeks of gestation.

When the level of hCG during the second screening is too high, this may indicate:

• about multiple pregnancy ;
• O diabetes at mother;
• about the risk of developing down syndrome if the other two indicators are below normal.

If hCG, on the contrary, is lowered, then this says:

• about risk Edwards syndrome ;
• O frozen pregnancy;
• O placental insufficiency .

When AFP levels are high, there is a risk of:

• anomalies in development kidney ;
• defects neural tube ;
• developmental disabilities abdominal wall ;
• damage brain ;
• oligohydramnios ;
• fetal death;
• spontaneous miscarriage;
• occurrence Rhesus conflict .

Decreased AFP can be a signal:

• Edwards syndrome ;
• diabetes mothers;
• low location placenta .

At a low level, the risk is high:

• development anemia in the fetus;
• adrenal and placental insufficiency;
• spontaneous miscarriage ;
• availability down syndrome ;
• development intrauterine infection ;
• delays in the physical development of the fetus.

It should be noted that at the level hormone E3 some drugs (for example,), as well as improper and unbalanced nutrition of the mother, affect. When E3 is elevated, doctors diagnose diseases kidney or multiple pregnancy, and also predict preterm birth, when the level of estriol rises sharply.

After the expectant mother goes through two stages of screening, doctors analyze the information received using a special computer program and calculate the same MoM coefficient as in the first study. The conclusion will indicate the risks for a particular type of deviation.

Values ​​are given as a fraction, such as 1:1500 (i.e. one in 1500 pregnancies). It is considered normal if the risk is less than 1:380. Then the conclusion will indicate that the risk is below the cut-off threshold. If the risk is higher than 1:380, then the woman will be referred for additional consultation with geneticists or offered to undergo invasive diagnostics.

It is worth noting that in cases where the biochemical analysis corresponded to the norms during the first screening (indicators were calculated HCG and PAPP-A ), then for the second and third time it is enough for a woman to do only an ultrasound.

The last screening examination of the expectant mother takes place in third trimester . Many people wonder what they look at at the third screening and when this study should be done.

As a rule, if a pregnant woman was not diagnosed with any abnormalities in the development of the fetus or during pregnancy at the first or second examination, then she only has to undergo an ultrasound examination, which will allow the specialist to draw final conclusions about the condition and development of the fetus, as well as his position in the womb.

Determining the position of the fetus ( head or breech presentation ) is considered an important preparatory stage before childbirth.

In order for the delivery to be successful, and the woman to give birth on her own without surgical intervention, the child must be in the head presentation.

Otherwise, doctors plan a caesarean section.

The third screening includes procedures such as:

• ultrasound , which is passed by all pregnant women without exception;
• dopplerography is a technique that focuses mainly on the condition of the vessels placenta ;
• cardiotocography - a study that allows you to more accurately determine the heart rate of a child in the womb;
• blood biochemistry , during which attention is focused on such markers of genetic and other abnormalities as the level hCG, α-fetoprotein and PAPP-A .

Timing of the third screening during pregnancy

It is worth noting that only the doctor decides how many weeks 3 screening a woman should undergo, based on the individual characteristics of this particular pregnancy. However, it is considered optimal when the expectant mother undergoes a planned ultrasound at 32 weeks, and then immediately passes a biochemical blood test (if indicated), and also undergoes other necessary procedures.

However, for medical reasons, dopplerography or KTG fetus can be from the 28th week of pregnancy. third trimester starts at 28 weeks and ends with childbirth at 40-43 weeks. The last screening ultrasound is usually prescribed at 32-34 weeks.

Deciphering ultrasound

At what time the third screening ultrasound passes a pregnant woman, we found out, now let's talk in more detail about the decoding of the study. When performing an ultrasound in the third trimester, the doctor pays special attention to:

• for the development and construction of cardio-vascular system a child to exclude possible developmental pathologies, for example,;
• for proper development brain , organs of the abdominal cavity, spine and genitourinary system;
• to those in the cranial cavity vein of Galen , which plays an important role in the proper functioning of the brain to eliminate aneurysm ;
• on the structure and development of the face of the child.

In addition, ultrasound allows a specialist to assess the condition amniotic fluid, appendages and uterus mothers, as well as check and placenta thickness . In order to exclude hypoxia and pathologies in the development of the nervous and cardiovascular systems , as well as to identify the features of blood flow in uterine vessels and the child, as well as in the umbilical cord, carry out dopplerography .

As a rule, this procedure is carried out only according to indications simultaneously with ultrasound. In order to exclude fetal hypoxia and define heart rate, carry out KTG . This type of research focuses solely on the functioning of the baby's heart, so cardiotocography prescribed in cases where the doctor has concerns about the condition cardiovascular child systems.

Ultrasound in the third trimester of pregnancy allows you to determine not only the presentation of the child, but also the maturity of his lungs, on which the readiness for birth depends. In some cases, to save the life of the child and the mother, hospitalization may be required for the purpose of early delivery.

Index	The average rate for 32-34 weeks of pregnancy
Placenta thickness	from 25 to 43 mm
Amniotic (amniotic) index	80-280 mm
Degree of placental maturity	1-2 degree of maturation
Uterine tone	absent
uterine pharynx	closed, length not less than 3 cm
Fetal growth	average 45 cm
Fetal weight	on average 2 kg
Girth of the abdomen of the fetus	266- 285 mm
BDP	85-89 mm
Fetal thigh length	62-66 mm
fetal chest circumference	309-323 mm
Fetal forearm size	46-55 mm
Fetal leg bone size	52-57 mm
Fetal shoulder length	55-59 mm

According to the results of a biochemical blood test MoM factor should not deviate from the range from 0.5 to 2.5. The risk value for all possible deviations must correspond to 1:380.

Education: Graduated from Vitebsk State Medical University with a degree in Surgery. At the university, he headed the Council of the Student Scientific Society. Advanced training in 2010 - in the specialty "Oncology" and in 2011 - in the specialty "Mammology, visual forms of oncology".

Experience: Work in the general medical network for 3 years as a surgeon (Vitebsk Emergency Hospital, Liozno Central District Hospital) and part-time as a district oncologist and traumatologist. Work as a pharmaceutical representative for a year in the Rubicon company.

He presented 3 rationalization proposals on the topic “Optimization of antibiotic therapy depending on the species composition of microflora”, 2 works won prizes in the republican competition-review of student scientific works (categories 1 and 3).

Screening of the 1st trimester is included in the general set of examinations during the gestation period to assess the health of the child and possible threats to gestation. Screenings are a common research method that applies not only to pregnant women: a referral for screening studies is also prescribed for newborns, as well as any population groups included in the risk group for developing any diseases, abnormalities, dysfunctions.

Screening studies allow you to determine the likely possibility of the presence of pathology. In the first trimester of pregnancy, screening combines an ultrasound examination and analysis of blood parameters, while the results are deciphered exclusively in a comprehensive analysis of both types of research.

First screening during pregnancy: period and timing of the study

During pregnancy, women are offered to undergo three screenings to identify and correct possible deviations in the course of pregnancy or fetal development in time.

1 screening is carried out in the first trimester. The terms of pregnancy in the classic version are set on the basis of an obstetric calculation, where the first day of the gestational period is the date of the start of the last menstruation before pregnancy. With the calendar method for determining the gestational age, experts start from the day of conception. However, since it is difficult to determine this date during physiological conception (the day of ovulation and the day of the fusion of the egg and sperm may differ by 3-5 days), it is recommended to adhere to an obstetric technique focused on the date of the last menstruation.

With a long menstrual cycle, the specialist can make changes to the screening dates, however, on average, the first screening study is carried out between 11 and 14 weeks of gestational age, limiting the upper limit of the period to 13 weeks and 6 days from the date of the start of the last menstrual bleeding.

Why was this period chosen for the first screening? At 12 obstetric weeks, the border between the embryonic and fetal or fetal developmental period passes: the unborn baby moves from the stage of the embryo to the fetus. The presence of formed structures and changes in the body make it possible to assign a new status to the future baby at the perinatal stage of development.

Also, this period is the minimum at which it is possible to identify the most common, although quite rare, deviations, as well as the reactions of the mother's body to the development of a new life.

Screening - voluntary research or obligation?

Since early diagnosis of probable deviations allows you to quickly and effectively help the expectant mother to correct possible negative consequences, screening studies during the gestation period are strongly recommended for all pregnant women, regardless of age, health status and the presence of healthy children. Deviations recorded during the study may occur spontaneously without correlation with the health of parents, relatives and lifestyle.

Despite the fact that the screening study is carried out in the direction of a gynecologist, screening can be waived. This procedure is voluntary, although it is recommended by the Ministry of Health as part of the medical support for pregnancy in any woman.

If screening is refused for one reason or another, it must be remembered that this study is useful for everyone, and in particular for certain categories of expectant mothers. The high-risk group includes:

• future mothers over the age of 35, regardless of previous experience of pregnancy and childbirth. This recommendation is associated with an increase in the number of probable chromosomal disorders in the beginning of the aging process;
• women who have been diagnosed with a condition that threatens spontaneous miscarriage or miscarriage, missed, non-developing pregnancy;
• a history of infectious diseases (including influenza, SARS during the first trimester);
• parents with genetic disorders, women who had a high risk of genetic abnormalities during previous pregnancies, the presence of pathologies or have children born with chromosomal abnormalities;
• pregnant women who are forced to take medications that are limited or prohibited during the gestation period or immediately before it, some types of vaccinations and medical procedures that preceded pregnancy in a short time;
• women whose pregnancy occurred as a result of a closely related relationship;
• women with addictions: alcohol, drug addiction, etc.

A screening study does not pose a risk to the fetus or mother, so the rejection of diagnostics, which can reveal easily correctable deviations at a given time, is at least unreasonable.

The study is carried out in public clinics free of charge. You can choose to undergo screening at any other clinic, if necessary, it is possible to re-conduct both a complete study and one of its stages, if the gestational age allows.

What is included in the first perinatal screening?

Screening in the first trimester of pregnancy is limited to an ultrasound examination of the condition of the fetus and uterus of a woman, as well as a biochemical study of the blood of a pregnant woman, in which the level of the corresponding hormones and the presence of certain markers are determined.

The size of the fetus, the characteristics of the development of its body parts, bones, the presence of certain parts of the circulatory system, in combination with the results of a blood test, make it possible to confirm the correct development of the child and the reaction of the mother's body, or to suspect the possibility of some deviations.

How to prepare for the first screening?

Ultrasound examination of the fetus and uterus can be carried out by two methods: using an apparatus with a transvaginal sensor or a transabdominal method of external examination through the surface of the peritoneum.

In the first case, preparation for the study consists in emptying the bladder immediately before the ultrasound, in the second, before the study, it is necessary to fill the bladder, which will create the necessary darkening and contrast. Filling the bladder should be done approximately 30 minutes before the start of the study, the required volume of fluid is from 0.5 to 0.7 liters. It is preferable to drink non-carbonated water and not go to the toilet, starting from 4 hours before the time of visiting a specialist until the end of the ultrasound.

During the procedure itself, the position of the fetus is an important factor. If the child lies in such a way that it is difficult to calculate the exact dimensions of some parts of the body, then the expectant mother may be asked to walk, bend over, strain and relax her stomach, imitate coughing, etc. At the same time, it is sometimes possible to determine the sex of the unborn child, however, for for a more accurate result, it is better to wait for the second ultrasound for a period above 20 weeks.

Blood biochemistry during screening of the first trimester should be carried out strictly after ultrasound. The blood formula in the mother's body during the gestation period changes daily, and without a correlation with the date of the ultrasound, the specialist will not be able to correctly interpret the analysis data.

For the most reliable results of a biochemical blood test, it is necessary to exclude all factors that may affect the functioning of various organs. Thus, preparation for the second stage of screening includes:

• exclusion from the diet of food-potential allergens for all women (cocoa products, nuts, shellfish, citrus fruits, out-of-season vegetables and fruits) and identified allergens for pregnant women with a history of allergic reactions. It is necessary to notify the specialist about the presence of an allergy at the time of screening or shortly before it, this will allow a more accurate assessment of the results of the analysis. It is not worth talking about the need not to take alcohol during pregnancy, but this rule is especially important before screening and applies even to small doses of alcohol on holidays;
• the last meal should be 12 hours before blood sampling for research, in the evening of the previous day. After the rise and before the analysis, you can not drink;
• just before blood sampling, you need to sit for 15-20 minutes, avoid stress, physical activity (jogging after the bus, climbing a long staircase, etc.).

Failure to comply with the above rules may lead to distortions in the test results, which may be incorrectly interpreted as a deviation in the development of the fetus or the course of pregnancy. Such unnecessary risks must be avoided.

Fetal parameters assessed by ultrasound at first trimester screening

In the process of ultrasound examination, the specialist evaluates the size of the fetus according to various indicators, as well as some important parameters of the child’s body at this period of development, the developmental features and condition of the placenta and uterus of the mother.

In the results of ultrasound during the first screening, you can see the following designations:

• KTR, or the length of the fetus from the crown of the head to the coccyx: this is how the process of intrauterine development denotes the “growth” of the child, since the most characteristic position of the fetus - with legs bent and drawn to the chest, especially in the later stages, does not allow determining the length of the entire body. Full "height" can be roughly estimated from the length of the femur bone, which, like the length of the bones of the shoulder and forearm, is an important indicator of fetal development;
• OG is an indicator of the size of the fetal head, measured in circumference (calculated based on the diameter);
• BDP is an indicator of the bioparental size of the head between the parietal bones. This indicator reflects both the development of the head structures of the fetus, and, in the later stages, allows us to make assumptions about the preferred method of delivery of the mother. With a large volume of the skull and a narrowed pelvis, most likely, a caesarean section will be offered. The distance from the forehead to the back of the child's head is also measured;
• TVP is an indicator of the thickness of the collar space or cervical fold of the fetus, assessed only in the first trimester. By week 16, this formation is transformed into new organs, and during the first screening for this indicator, in combination with blood markers, the absence or increased likelihood of chromosomal disorders is diagnosed;
• the thickness of the nasal bone as a probable indicator of the presence of genetic abnormalities is measured by ultrasound at 12-13 weeks, ultrasound at 11 obstetric weeks in most cases only allows you to notice its presence and the beginning of formation;
• structural features of the brain, skull bones: this indicator describes how symmetrically and in accordance with the norm the cranium and brain tissues of the fetus develop;
• Heart rate, an indicator of heart rate or heartbeat, is estimated according to the age norm. Also, when examining the heart, if possible, the specialist studies the size, structural sections of the heart muscle. The localization of the heart, stomach, large arteries and veins is also examined;
• localization of the chorion (placenta), the thickness of this organ. In later studies, the presence and number of calcifications will also be studied - inclusions indicating the physiological aging of the placenta;
• the number of umbilical vessels;
• the volume and condition of the amniotic fluid;
• characteristics of the tone of the uterus and cervical pharynx.

Average values ​​of the main parameters in accordance with the weeks of pregnancy:

Interpretation of the results of biochemical screening of the first trimester

The main indicators that specialists are guided by when deciphering the results of a biochemical blood test at this stage are the level of human chorionic gonadotropin, the hCG pregnancy marker hormone, and plasma protein A, or PAPP-A.

The fetal membrane (chorion), which begins to form immediately after the fertilization of the egg by the sperm, produces chorionic gonadotropin on the very first day. However, the reference values ​​that allow determining pregnancy, this hormone reaches no earlier than after 2 weeks. Highly sensitive express tests and a blood test for pregnancy determine the presence of this particular component.

In the first weeks of pregnancy, the level of chorionic gonadotropin increases, doubling the rates almost daily. The level of this hormone reaches its peak concentration by 11-12 weeks, then there is a decrease and fixation at insignificant levels.
High hCG in relation to the norm may indicate the following abnormalities and / or physiological conditions:

• multiple pregnancy, in which the hormone is produced by several chorions;
• endocrinological diseases of the mother (diabetes mellitus) in history or developing against the background of gestation;
• manifestation of severe toxicosis of the first trimester;
• chromosomal disorder - Down syndrome in the fetus.

Reduced relative to reference values, the level of human chorionic gonadotropin (hCG) may indicate the following disorders:

• placental insufficiency;
• the presence of an ectopic pregnancy;
• increased risk of miscarriage, spontaneous abortion;
• genetic disorder - Edwards syndrome in the fetus.

When assessing the level of PAPP-A, only low values ​​matter. They may indicate a threatened abortion due to an inadequate response of the mother's immune system or insufficient functioning of the placenta, as well as some chromosomal abnormalities in the fetus.

Comprehensive interpretation of screening results

The results of the screening of the first trimester after a full assessment of all indicators will contain the following data:

• risks of deviations associated with the age of the mother;
• assessment and interpretation of biochemical parameters of the mother's blood;
• the likelihood of the presence or occurrence of various diseases;
• MoM value.

Based on the results of an ultrasound examination and a biochemical blood test, specialists bring the data together and assign the so-called MoM index (multiple of median). This coefficient is formed on the basis of variable indicators typical for the range of results of studies of healthy women with a normal pregnancy and a fetus developing in a timely manner.

The norms for the first screening are from 0.5 to 2.5 units for a singleton pregnancy, and up to 3.5 if two or more babies are expected.
After calculating the IOM, the results are entered into the program, which takes into account all the factors that affect the health of the mother and child and the course of pregnancy: age, height-to-weight ratio, certain diseases (in particular, diabetes), the presence of bad habits (smoking), the number of children born fetuses, physiological or extracorporeal method of conception, etc.

Based on the evaluation of all data, the program provides a probable risk of genetic abnormalities in the fetus. The result is presented as a ratio of 1:1000 for several genetic diseases, expressing the risks of this syndrome in each specific case. An index of 1:380 or more is considered positive for a low risk of violations, an index below 1:380 means an increase in risk.

But this indicator is not a final diagnosis, but an assessment of probabilities. So, if the conclusion of a specialist contains an index of 1:70 to Down syndrome, this means that only 1 out of 70 women with similar results has a child with developmental disabilities. In 69, pregnancy proceeds without deviations and ends with the birth of a healthy child.

The following factors influence the distortion of the results:

• non-compliance with the rules of preparation for biochemical analysis;
• outdated ultrasound equipment;
• in vitro fertilization;
• endocrinological disorders (diabetes mellitus of both types);
• multiple pregnancy;
• increased body mass index of the mother (overweight).

What to do if screening results are disappointing?

Many women are afraid to pass the “first exam” in the life of the fetus, afraid of both hearing negative news and hasty appointments and even pressure to terminate the pregnancy. If there are doubts about the results, you can undergo additional screening, following the rules for preparing and alternating ultrasound and biochemistry, and assess the condition and results in the complex.

In fact, “high risk” is diagnosed at rates from 1:250 to 1:380 for any syndrome, which means a slightly increased, but not necessarily, probability of a child having genetic abnormalities. With such indicators, it is recommended to lead a healthy lifestyle, regularly see a gynecologist and consult a geneticist.

In some cases, a geneticist may offer to undergo an additional examination for accurate diagnosis (chorionic villus biopsy, amniocentesis, cordocentesis), on the basis of which recommendations for parents will be made.